The Drill Press

B r n YOUR rn MBTAL WORXING SHOP FROM SCRAP

Ths Drill Press .1

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..

Written and Illustrated by David J. Gingery

FIRST EDITION FIRST PRINTING 1982

copyright

@ 1982 David J. Gingery

LIBRARY OF CONGRESS CATALOG CARD NUMBER 80-66142

INTERNATIONAL STANDARD BOOK NUMBER 0-9604330-4-x

DAVID J. GINGERY METAL SHOP FROM SCRAP 2045 Boonvi 1 l e S p r i n g f i e l d , Mo. 65803

IT

CONTENTS PAGE

CHAPTER

I I1 111 IV

v

VI VII VIII

CONSTRUCTION METHODS-------------------F I T T I N G OUT T H E LATHE------------------T H E COLUMN AND BASE--------------------T H E Q U I L L FEED MECHANISM---------------T H E QUILL------------------------------T H E S P I N D L E DRIVE----------------------T H E MOTOR DRIVE------------------------T H E WORK TABLE--------------------------

INDEX TO MAJOR SUB HEADINGS----------------------

T H E METHODS AND MATERIALS THAT ARE SUGGESTED I N T H I S MANUAL WERE DEVELOPED BY A NONPROFESSIONAL. THE AUTHOR I S NOT AN ENGINEER OR S C I E N T I S T . NO L I A B I L I T Y I S A S S U M E D FOR I N J U R Y TO PERSONS OR PROPERTY THAT MAY R E S U L T FROM THE USE O F T H I S INFORMATION.

I t ' s t r u e t h a t you can buy a small d r i l l p r e s s f o r a moderate p r i c e , b u t t h a t would d e p r i v e you of t h e fun of b u i l d i n g one, and you would n o t g a i n t h e s k i l l and knowl e d g e t h a t w i l l be developed by t h e s e e x e r c i s e s . I f you have followed t h e s e r i e s i n s e q u e n c e , and comp l e t e d t h e l a t h e , t h e shaper and t h e m i l l e r , you w i l l have done c o n s i d e r a b l e d r i l l i n g w i t h your e l e c t r i c h a n d d r i l l . This i s t e d i o u s work, and f r u s t r a t i n g too, f o r i t t a k e s p r a c t i c e t o produce a h o l e t h a t i s i n l i n e and on c e n t e r w i t h a hand d r i l l . No doubt your d e s i r e t o own a d r i l l p r e s s i s much g r e a t e r than when you began. The p a t t e r n s and c a s t i n g s f o r t h e d r i l l p r e s s a r e n o t d i f f i c u l t i f y o u have t h e back ground of t h e e a r l i e r proj e c t s , s o w e ' l l spend m o r e t i m e d i s c u s s i n g m a c h i n i n g o p e r a t i o n s than we w i l l on foundry. When I began, I expected t o make c o n s i d e r a b l e u s e of both t h e m i l l i n g machine and t h e shaper t o machine t h e c a s t i n g s , b u t t h e home made l a t h e w i t h i t s 7" swing was e a s i l y capable of doing a l l o f t h e work except m i l l i n g t h e keyway i n t h e s p i n d l e . I t would appear t h a t t h e d r i l l p r e s s could have been p r e s e n t e d e a r l i e r i n t h e s e r i e s because it h a s such a simp l e appearance, but t h e r e a r e some e x a c t i n g requirements i n t h e machining o p e r a t i o n s t h a t I f e e l would have d i s couraged many. W e a r e s t i l l working w i t h simple a c c e s s o r i e s , and t h e p r o j e c t i s a d d i t i o n a l p r o o f o f t h e w o r t h o f a simple l a t h e equipped w i t h no more than a f a c e p l a t e and c e n t e r s . The d r i l l p r e s s w i l l be a v i t a l n e c c e s s i t y f o r b u i l d i n g t h e d e l u x e a c c e s s o r i e s though, and s o w i l l t h e a d d i t i o n a l s k i l l and knowledge t h a t you w i l l a c q u i r e wlth t h i s p r o j e c t . The d e s i g n e x c e e d s t h e n e e d s of most home shop operat i o n s , f o r it w i l l d r i l l a 518" h o l e i n s t e e l w i t h e a s e . I t can be s c a l e d down t o a s m a l l e r s i z e e a s i l y , o r you can s c a l e i t up t o a h e f t y f l o o r model i f you want t o . Keep i n mind t h a t s o m e o f t h e p a r t s u s e t h e e x t r e m e c a p a c i t y of t h e l a t h e though, s o you w i l l have todepend on t h e l a r g e r swing of t h e m i l l e r o r a l a r g e r l a t h e i f you s c a l e up. The d r i l l p r e s s i s l i k e l y t o b e t h e g r e a t e s t c h a l l e n g e I t w i l l c e r t a i n l y be t h e most used machine i n t h e yet. shop, and you w i l l b e a f a r b e t t e r machinist and mechanic when you have b u i l t i t .

Slate's Se~zsifh~ Drill.

INTRODUCTION

The engravings o f o l d m a c h i n e s i n e a r l i e r manuals have been an aid i n d e s c r i b i n g t h e design and f u n c t i o n of each machine. Modem machines have been much improved, but t h e e s s e n t i a l elements of design remain t h e same. I have some f i n e old engravings o f " camel back " d r i l l i n g machines, but I t h i n k S l a t e s " S e n s i t i v e " d r i l l p r e s s is t h e best i l l u s t r a t i o n fordiscussion in t h i s project. I t h a s i n t e r e s t i n g f e a t u r e s t h a t a r e o b v i o u s , but t h e r e a r e d e s i g n cons i d e r a t i o n s t h a t might escape n o t i c e i f n o t pointed o u t . Like t h e o t h e r engravings, t h i s one i s from an 1888 H i l l and Clarke c a t a l o g . Note t h a t t h e bracket which supports t h e driven pull e y and t h e cone p u l l e y i s c a s t and machined s e p a r a t e l y . I t was p o s s i b l e t o a d j u s t t h e bracket t o bring t h e spind l e e x a c t l y perpendicular t o t h e t a b l e and p a r a l l e l t o t h e column. This i s t h e f i r s t v i t a l design c o n s i d e r a t i o n i n building an a c c u r a t e d r i l l p r e s s . The t a b l e could n o t b e r a i s e d o r l o w e r e d , b u t t h e q u i l l support would be moved up o r down f o r t h e same purpose. The s p i n d l e was mounted i n c l o s e f i t t i n g bearings i n t h e q u i l l , and i t s upper end passed through t h e h u b o f t h e d r i v e n p u l l e y which was mounted i n i t s own bearings. No b e l t t e n s i o n was t r a n s f e r r e d t o t h e s p i n d l e . I t i s most l i k e l y t h a t t h e b e a r i n g s were poured babbit, though i t m a y have had a b a l l t h r u s t bearing on t h e q u i l l . The feed l e v e r r o t a t e s a s m a l l pinion gear which f i t s a rack milled i n t h e q u i l l , and t h e q u i l l support i s s p l i t S O t h a t i t can be adjusted c l o s e l y t o t h e q u i l l a f t e r it wears i n use. The t a b l e could be swung a s i d e s o t h a t a s h a f t could be s e t i n t h e cup c e n t e r f o r accurate c e n t e r d r i l l i n g . An a d d i t o n a l accessory clamp was a v a i l a b l e f o r g r i p p i n g t h e upper end of t h e s h a f t . The machine sold f o r $80.00 i n 1888, and i t was offered a s a bench model without t h e p e d e s t a l f o r $60.00. That was a p r e t t y high p r i c e f o r such a s i m p l e machine i n those days, and t h e reason i s t h e amount of hand work t h a t was I think neccessary t o f i n i s h i t t o p r e c i s e standards. we have advanced more i n t h e design of d r i l l i n g machines than i n any o t h e r of t h e machine groups. You can buy a small d r i l l p r e s s complete with motor f o r about $150.00, and i t i s a b e t t e r machine than t h i s e a r l y model. Such a 6

comparison i n other machine groups shows t h a t t h e r e must have been a l a g i n i n t e r e s t and lack of competition i n t h e manufacture and marketing of d r i l l i n g machines, f o r l a t h e s and m i l l e r s and shapers were remarkably cheap by compari s o n . I t was n o t u n t i l theround column appeared t h a t i t b e c a m e p o s s i b l e t o m a s s p r o d u c e d r i l l i n g machines cheaply. S l a t e ' s machine was termed a " s e n s i t i v e " d r i l l bec a u s e t h e o p e r a t o r could f e e l t h e amount of feed p r e s s u r e with h i s hand. I t i s a t t h e moment t h a t t h e d r i l l p o i n t c u t s through t h e m a t e r i a l t h a t small d r i l l s break, and a reduction of feed p r e s s u r e i s needed a t t h a t moment. I f t h e r e i s excess v e r t i c a l play i n t h e s p i n d l e t h e advantage of a s e n s i t i v e hand feed i s l o s t . Our d r i l l p r e s s w i l l lookmuch d i f f e r e n t , but t h e same considerations must be kept i n mind as you make each p a r t and assemble them. As t h e bed i s t h e foundation of t h e l a t h e , t h e column i s t h e foundation of t h e d r i l l p r e s s . A l l of t h e members of t h e d r i l l p r e s s a r e e i t h e r p a r a l l e l t o t h e c o l u m n o r a t exact r i g h t angles t o i t . With c a r e , you can produce t h e p a r t s t o n e a r p e r f e c t i o n , and you can e a s i l y i n s t a l l shims t o c o r r e c t f o r small e r r o r s i f you h a v e n o t y e t developedthekeen eye and s e n s i t i v e f i n g e r s . You w i l l c e r t a i n l y grow i n s k i l l as you machine each p a r t , andyour simple l a t h e w i l l win y o u r r e s p e c t as i t performs t h e s e operations without t h e a i d of expensive a c c e s s o r i e s and t o o l i n g . The machining operations a r e t u r n i n g , boring and fating o f f , and y o u w i l l h a v e acquired t h e s e s k i l l s i n e a r l i e r p r o j e c t s i n t h e s e r i e s . The important v a r i a t i o n s a r e i n You s e t t i n g up t h e work and holding i t f o r machining. w i l l g a i n s o m e new simple a c c e s s o r i e s f o r f u t u r e p r o j e c t s as you f i t out t o machine t h e p a r t s f o r t h e d r i l l p r e s s . A l l of t h e p a t t e r n s a r e of simple shape and easy t o mold and c a s t . They a r e a l l within t h e c a p a c i t y of t h e charcoal foundry using t h e one q u a r t p o t . Like t h e o t h e r home made machines, t h e p r o j e c t may be a b i t i n t i m i d a t i n g , but I u r g e y o u t o g o ahead and t r y out your s k i l l . Once you have t h e base and column b u i l t you a r e not l i k e l y t o w a n t t o s t o p . I t may take s i x weeks, o r i t may t a k e s i x months. In e i t h e r c a s e you w i l l n o t have a s e r i e s of monthly back breaking payments t o make, and you w i l l own s t i l l another f i n e machine you have b u i l t .

CHAPTER I CONSTRUCTION METHODS

I t w i l l be t h e boast of every m a n u f a c t u r e r o f a modern d r i l l p r e s s t h a t t h e head of h i s machine i s c a s t i n one p i e c e and t h a t i t i s p r e c i s e l y machined s o t h a t t h e column and s p i n d l e a r e e x a c t l y p a r a l l e l . He i s j u s t l y ent i t l e d t o h i s b o a s t , f o r t h e s i m p l i c i t y , d u r a b i l i t y and accuracy of modern machines i s amazing. The product i s a t r i b u t e t o t h e s k i l l and genius of t h e e n g i n e e r , p a t t e r n maker, molder and machinist. I t r e q u i r e s g r e a t s k i l l , knowledge and experience t o design a p a t t e r n f o r t h e mass production of such an item a s t h e head f o r a d r i l l p r e s s . There a r e hundreds of det a i l s t o consider, and a s i n g l e e r r o r can c r e a t e a g i a n t heap of scrap i r o n . Our job ismuch e a s i e r because we a r e only b u i l d i n g one d r i l l p r e s s , and we're n o t g o i n g t o t r y t o c a s t t h e head i n one p i e c e . FOUNDRY WORK Having separated t h e major p a r t s of t h e machine i n t o manageable sub assemblies, t h e r e a r e no d i f f i c u l t p a t t e r n s t o make and most of t h e molding i s r o u t i n e p r a c t i c e . We won't have t o d i s c u s s it i n d e t a i l except t o review some of t h e b a s i c p r i n c i p l e s when t h e need a r i s e s . PATTERN MAKING A l l of t h e p a t t e r n s a r e simple r e c t a n g u l a r o r c y l i n d r i c a l shapes, o r combinations joined with g l u e andbrads. I t ' s worth t h e time and t r o u b l e t o produce accurate and smoothly f i n i s h e d p a t t e r n s because thewood o f t h e p a t t e r n i s much e a s i e r t o work than t h e metal of t h e c a s t i n g . Draft i s t h e a l l important f a c t o r , but i t must n o t be over done. Very shallow p a t t e r n s c a n b e made with l i t t l e o r n o d r a f t because rapping w i l l e n l a r g e t h e c a v i t y enough s o t h a t t h e p a t t e r n c a n be c l e a n l y drawn from t h e mold. A p a t t e r n w i t h depth of 3" does n o t need a g r e a t e r angle of d r a f t than one o f l " depth, but t h e d r a f t ismuch more i m p o r t a n t o n t h e d e e p e r p a t t e r n . With few exceptions, d r a f t of one degree i s more than adequate f o r t h e p a t t e r n s i n t h i s project.

8

The nominal dimensions i n t h e p a t t e r n drawings r e f e r t o the s i z e o f t h e p a t t e r n a t the parting plane. I t w i l l u s u a l l y be b e s t t o c u t t h e p a t t e r n t o t h e nominal s i z e , and then form t h e d r a f t w i t h a s a n d i n g block. A l l v e r t i c a l s u r f a c e s s l o p e s l i g h t l y t o a s m a l l e r dimension than a t t h e p a r t i n g p l a n e . T e s t t h e angle of d r a f t by holding a small t r y square a g a i n s t t h e p a r t i n g p l a n e t o make s u r e the v e r t i c a l surfaces slope s l i g h t l y .

BARELY PERCEPTIBLE DRAFT

+TRY

SQUARE

PATTERN PARTING PLANE When more t h a n o n e v e r t i c a l r i b o r w e b b f o r m s a c h a n n e l , t h e i r a x i s must be a t e x a c t r i g h t a n g l e s t o t h e p a r t i n g p l a n e s o t h e p a t t e r n won't be locked i n t h e mold. 'PARALLEL

I

!

I

WILL LOCK I N MOLD

CORRECT

F i l l e t s a r e t h e s l i g h t l y rounded junction a t i n s i d e c o r n e r s . They l e a v e a c l e a n e r c a v i t y and r e l i e v e s t r a i n a t t h e c o r n e r s when t h e metal s o l i d i f i e s , but i f they a r e made t o o l a r g e they cause s h r i n k c a v i t i e s . Outside corn e r s a r e s l i g h t l y rounded except a t t h e p a r t i n g p l a n e .

ROUNDED

COHMON PROBLEMS Aluminum c a s t i n g s r e q u i r e sprues and r i s e r s a p u t t h r e e times as l a r g e a s i r o n c a s t i n g s . You could hardly use a sprue t h a t was too l a r g e u n l e s s you exceed your melting c a p a c i t y , but one t h a t i s too small w i l l cause a shrink flaw i n t h e c a s t i n g . Too much water i n t h e sand and f a i l u r e t o vent with t h e wire w i l l cause depressions i n t h e s u r f a c e of t h e c a s t i n g t h a t look much l i k e shrink c a v i t i e s . Rammingtoohard can produce t h e same e f f e c t . I f t h e sand i s too dry, o r i f you allow t h e mold t o stand too long before pouring, you may c a r r y l o o s e sand i n t o t h e c a v i t y when you pour. Newly tempered sand i s d i f f i c u l t t o work because t h e moisture i s n ' t u n i f o r m l y spread throughout t h e sand. It improves a g r e a t d e a l a f t e r standing f o r s e v e r a l hours. I always shake o u t my c a s t i n g s d i r e c t l y i n t o t h e r i d d l e placed i n my sand bin. Then I r i d d l e t h e sand t o leave only t h e hardened lumps i n t h e r i d d l e . These I break up and r i d d l e i n t o t h e bin, s p r i n k l e t o r e p l a c e l o s t water, and mix it up with t h e main body of sand.. When I c l o s e up shop I c o v e r t h e s a n d bin wlth p l a s t i c t o p r e v e n t evapo r a t i o n so my sand i s ready when ever I need i t . F i l l t h e f l a s k i n progressive l a y e r s of about 2" thickness, and ram each l a y e r uniformly. I f there are soft s p o t s o r empty corners i t ' s because you were n o t systema t i c andthorough with your ramming. Press sand i n t o t h e c o r n e r s a n d s m a l l core a r e a s with your f i n g e r s before you begin general ramming. I f you attempt t o s l i c k up t h e p a r t i n g f a c e of t h e drag a f t e r t h e copeisrammed you a r e l i k e l y t o have a run out a t t h e p a r t i n g l i n e when you pour. Don't d i s t u r b t h e f a c e of t h e drag once t h e cope i s rammed up. P o u r i n g t o t h e s i d e of t h e sprue w i l l wash loose sand i n t o t h e c a v i t y . Pour d i r e c t l y i n t o t h e opening as f a s t a s it w i l l accept t h e metal, and d o n ' t stop u n t i l i t i s completely f i l l e d . I f g a t e s and runners a r e too small i t h a s thesame eff e c t as an undersize s p m e o r r i s e r . They should be from 2 1 3 t o 314 t h e v o l u m e o f t h e sprue o r r i s e r , and as s h o r t as p r a c t i c a l . Use a l i g h t t o examine t h e c a v i t y , and swab any a r e a s t h a t t h r e a t e n t r o u b l e . Dustnewly swabbed areas with p a r t ing t o harden them up.

11

CHAPTER I1 FITTING OUT THE LATHE

These simple a c c e s s o r i e s w i l l handle a l l of t h e work t h a t would normally r e q u i r e a t h r e e o r f o u r jaw chuck, and they w i l l be a v a l u a b l e a d d i t i o n t o your shop f o r f u t u r e projects. A PLAIN ANGLE PLATE Someofthe c a s t i n g s c a n b e b o l t e d d i r e c t l y t o t h e f a c e p l a t e tomachine them, but o t h e r s w i l l have t o be mounted For a t r i g h t angles t o t h e t u r n i n g a x i s of t h e l a t h e . t h i s you need an angle p l a t e . Only one p a t t e r n i s r e q u i r e d , but it t a k e s an angle p l a t e tomachine another one s o y o u ' l l have t o c a s t two of them from t h e same p a t t e r n . The s h o r t e r l e g of t h e angle i s t h e mounting l e g , and it n e e d s t o b e rounded t o c l e a r t h e bed when mounted n e a r t h e r i m of t h e f a c e p l a t e . I realized t h i s a b i t late, s o y o u ' l l n o t i c e t h a t t h o s e i n t h e photos have n o t y e t been rounded o f f . I had t o do i t t h e hard way l a t e r .

THE ANGLE PLATE PATTERN Two simple shapes of white pine joined with glue and brads. Only a minimum of d r a f t i s r e q u i r e d , and wipe a very small f i l l e t a t t h e i n s i d e corner of t h e angle.

2"

DRAFT

MOLDING THE ANGLE PLATE This i s a r o u t i n e mold w i t h t h e e n t i r e p a t t e r n i n t h e drag. Ram up t h e p a t t e r n i n t h e d r a g , r o l l over and s e t Ram up a 1 114" sprue p i n about 1" away from t h e base. the cope, open t h e mold t o draw t h e p a t t e r n and c u t t h e g a t e , and c l o s e up t o pour. Make twomolds from t h e same p a t t e r n and pour them a t thesame time. I t w i l l be more economical t o o p e r a t e your foundry i f you p r e p a r e anumber of molds t o be poured with each melt s o t h a t you u s e up t h e e n t i r e f u e l charge. A s t h e f u e l bed s e t t l e s , add c h a r c o a l i n s i n g l e l a y e r s f r e q u e n t l y t o m a i n t a i n t h e h e i g h t of t h e bed. To add l a r g e amounts w i l l c o o l o f f t h e f i r e and waste f u e l . The broad f l a t s u r f a c e o f t h i s c a s t i n g w i l l be s l i g h t l y concave because of normal shrinkage. A machining allowance has been m a d e s o t h e r e w i l l be ample t h i c k n e s s a f t e r i t i s faced o f f smooth.

MACHINING THE ANGLE PLATES The f i n a l a c c u r a c y o f t h e angle p l a t e s w i l l bedependent upon t h e t r u e n e s s of your f a c e p l a t e and t h e l a t h e c r o s s slide. R o t a t e t h e f a c e p l a t e t o s e e i f it wobbles. I f it does i t i s bent and you must s t r a i g h t e n i t and f a c e i t o f f t o t r u e i t up. T e s t t h e s u r f a c e o f t h e p l a t e w i t h agood s t r a i g h t edge t o s e e i f i t i s c o n c a v e o r convex. I f your c r o s s s l i d e i s traveling a t exact r i g h t angles t o t h e turning axis i t w i l l be p e r f e c t l y f l a t when faced o f f . C o r r e c t any e r r o r by s c r a p i n g t h e f r o n t v e r t i c a l pad o f t h e c a r r i a g e box s l i d e . With t h e l a t h e a t normal s t a n d a r d s of accuracy you a r e ready t o begin machining t h e angle p l a t e s . D r i l l and t a p f o u r 5116"-18 h o l e s i n each c a s t i n g a s shown i n t h e drawing.

These tapped h o l e s w i l l s e r v e f o r mounting t h e c a s t i n g s f o r machining, and w i l l a l s o be used i n t h e d i f f e r e n t o o e r a t i o n s on t h e d r i l l p r e s s c a s t i n g s . Other h o l e s can be d r i l l e d o r tapped f o r f u t u r e j o b s . The f i r s t s t e p i s t o f a c e o f f t h e l a r g e s u r f a c e of t h e c a s t i n g s . J u s t b o l t t h e c a s t i n g t o t h e face p l a t e with a cap screw t h r o u g h t h e f a c e p l a t e , u s i n g a bushing o r some s e t screw c o l l a r s i n a s t a c k f o r s p a c e r s . One b o l t w i l l clamp i t s e c u r e l y enough t o t a k e moderate c u t s a s you make s e v e r a l p a s s e s t o b r i n g t h e s u r f a c e smooth and f l a t . Yo a t t e m p t i s m a d e a t t h i s p o i n t tomake t h e b a s e a n g l e t r u e , and t h e f i n i s h e d t h i c k n e s s i s n o t c r i t i c a l . Even i f t h e t h i c k n e s s f i n i s h e s up a t a s l i t t l e a s 112" t h e p l a t e w i l l b e s t r o n g enough. Face o f f b o t h c a s t i n g s , and t h e r e i s no need t o make them of e q u a l t h i c k n e s s .

" n ? ifcon:! s ' i s to ' ' 1 ~ , a of one o r t h e s e faced o f f a n ~ l e sto t h e f a c e p l a t e w i t h t h e machined s u r face a t exact r i g h t angles t o the face p l a t e . Because of t h e d r a f t t h e a n g l e w i l l be g r e a t e r t h a n 9 0 d e g r e e s , s o you need t o a d d s h e e t m e t a l shims t o b r i n g F i l e t h e c o r n e r of it t r u e square v i t h t h e f a c e p l a t e . t h e a n g l e s o i t r e s t s f i r m l y on t h e f a c e p l a t e , and u s e a s i n g l e b o l t t h r o u g h t h e f a c e p l a t e s l o t i n t o t h e tapped h o l e

I n t h e base t h a t i s n e a r e s t t o t h e c e n t e r . T e s t w l t h an a c c u r a t e s q u a r e , and add shills u n t i l t h e a n g l e i s t r u e . Re-check t h e a n g l e a f t e r t i g h t e n i n g t h e b o l t f i r m l y , and be c a r e f u l not t o d e f o r m t h e f a c e p l a t e by o v e r - t i g h t e n i n g t h e mounting b o l t .

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FACE OFF

14" BOLTS AND NUTS

This w i l l g l v e you one t r u e a n g l e p l a t e , a n d v o u n e e d o n l y b o l t t h e f a c e d o f f b a s e on t h e f a c e p l a t e w l t h o u t t h e shims t o machine t h e second a n g l e p l a t e t n l e s q u a r e .

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FACE OFF

The q u i l l g u i d e i s o n e of t h e c a s t i n g a s s e m b l i e s t h a t i s mounted on t h e a n g l e p l a t e f o r b o r i n g . Note t h e weights t h a t a r e added f o r c o u n t e r b a l a n c i n g t h e work.

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A number o f s m a l l e r p a r t s need t o be bored a c c u r a t e l y s o t h a t t h e y can be mounted on an a r b o r between c e n t e r s . The s p r u e forms a handy shank f o r mounting them i n t h e V block a n g l e p l a t e . A s t a r t i n g h o l e i s d r i l l e d , t h e y a r e bored t o s i z e , a s e t screw i s i n s t a l l e d and t h e y a r e c u t from t h e s p r u e t o be mounted on t h e a r b o r .

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MOLDING THE SPLIT PATTERN

R a m up t h e d r a g h a l f p a t t e r n j u s t a s you d i d f o r t h e p l a i n angle p l a t e s . Vent with t h e w i r e , r u b i n a bottom board and r o l l over. The p i n s i n t h e cope h a l f a r e meant t o f i t f r e e l y s o t h a t t h e p a r t s w i l l s e p a r a t e when t h e mold i s opened. S e t t h e cope p a r t s i n p l a c e , s e t a 1 114" s p r u e p i n about 1" away from t h e base and ram up t h e cope. Remove t h e s p r u e p i n and c u t t h e s p r u e opening t o a f u n n e l shape. Vent t h e cope, r u b i n a bottom board and open t h e mold. Lay t h e cope down on t h e bottom board t o swab, r a p and draw t h e p a t t e r n p a r t s . You should be a b l e t o g r a s p t h e p i n s w i t h a small p l i e r s t o l i f t o u t t h e p a t t e r n p a r t s . Drive a p e g i n t o t h e d r a g h a l f p a t t e r n , swab a l l around t h e p a t t e r n , r a p and draw i t from t h e mold. Cut t h e g a t e , c l e a n up and f i n i s h c a r e f u l l y , and c l o s e up t o pour. THE CLAMP BAR

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The i n v e r t e d V block h a s an included angle of 90 deg r e e s , and s o does t h e small V. Molding i s r o u t i n e a s f o r any simple p a t t e r n , and t h e mold i s fed w i t h a 1 114" s p r u e .

MACHINING THE BASE A 1" diameter by 8" long a r b o r w i l l beneeded f o r some of t h e machining o p e r a t i o n s , and it w i l l s e r v e t o h o l d t h e V block angle p l a t e t o f a c e o f f t h e mounting base.

D r i l l a 114" h o l e c e n t e r e d 1 / 2 " f r o n each end of t h e clamp b a r , and u s e t h e b a r a s a g u i d e t o d r i l l matching 114" h o l e s i n t h e main body of t h e a n g l e p l a t e . Tap t h e h o l e s i n t h e a n g l e p l a t e f o r 5/16"-18 t h r e a d s , and e n l a r g e t h e h o l e s i n t h e c l a ~ pb a r t o 318". F i l e t h e V n o t c h e s i n t h e a n g l e p l a t e t o b r i n g them a s n e a r i d e n t i c a l a s p o s s i b l e . You can u s e a l a r g e p i e c e o f s q u a r e s t o c k a s a guage. Clamp t h e f i x t u r e t o t h e a r b o r and mount i t betveen c e n t e r s on t h e l a t h e t o f a c e o f f t h e mounting l e g . D r i l l and t a p two 5/16"-18 h o l e s i n t h e b a s e on t h e same dimensions a s f o r t h e p l a i n a n g l e p l a t e . When b o l t e d t o t h e f a c e p l a t e , work clamped i n t h e V b l o c k s w i l l be h e l d p a r a l l e l t o t h e t u r n i n g a x i s of t h e lathe. I n o r d e r t o b e a t r u l y p r e c i s i o n f i x t u r e the V notches would have t o be a b s o l u t e l y i d e n t i c a l , b u t i t w i l l a l i g n work w i t h i n a f r a c t i o n of one d e g r e e i f you u s e r e a s o n a b l e c a r e a s you f i t them by hand. T h i s w i l l be a d e q u a t e f o r t h e needs of t h i s p r o j e c t and most o p e r a t i o n s t h a t a r e t o be done i n t h e home shop.

II

DKiLLIUG, TAPPIUG 4VD B O R I N G IdITI1 T3E LATHE Yanv of t h e h o l e s can be d r i l l e d and tapped by hand, b u t a few must be done on t h e f a c e p l a t e u s i n g t h e t a i l s t o c k chuck. You c a n o r d e r a 112" chuck w i t h a '11 Morse t a p e r a d a p t e r from Wholesale Tool Co., and i t w i l l prov i d e t h e needed a c c e s s o r y f o r t h e t a i l s t o c k and a l s o t h e chuck f o r t h e d r i l l p r e s s when i t i s c o m p l e t e . I n t h e p h o t o below, t h e work t a b l e clamp b a s e i s b o l t ed t o t h e f a c e p l a t e w i t h a s h o r t l e n g t h o f p i p e a s t h e S p a c e r s o t h a t t h e f a c e d o f f s u r f a c e w i l l be p a r a l l e l t o t h e column. A s m a l l d i m p l e was c u t i n t h e c e n t e r of t h e f a c e d o f f s u r f a c e t o s t a r t t h e d r i l l , and a 5/16" t a p s i z e d r i l l i s h e l d i n t h e t a i l s t o c k chuck and f e d i n t o t h e work w i t h t h e t a i l s t o c k screw. The v i s e g r i p p l i e r s p r e v e n t t h e shank of t h e a d a p t e r from t u r n i n g . The same method i s u s e d t o d r i l l t h e s t a r t i n g h o l e f o r h o l e s t h a t must be bored t o a p r e c i s e s i z e . - -----It3

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$11 :,peratlo?:; ,?re co-,?ic!r?i ; % i : ~ i t l it i t h e ori g i n a l s e t u p on t h e f a c e p l a t e , s o t h e Faced o f f s u r f a c e w i l l be p a r a l l e l t o t h e column, and t h e tapped h o l e w i l l be e x a c t l y p e r p e n d i c u l a r t o t h e f a c e d o f f s u r f a c e . Work t h a t i s t o be bored ismounted e i t h e r d i r e c t l y t o the face p l a t e , with spacers t o give clearance f o r holes t h a t a r e bored through, o r w i t h on of t h e a n g l e f i x t u r e s . There w i l l be more time s p e n t i n b o r i n g t h a n i n any o t h e r p h a s e o f c o n s t r u c t i o n . These o p e r a t i o n s w i l l d e t e r mine t h e u l t i m a t e accuracy o f t h e d r i l l p r e s s , s o they must be done w i t h g r e a t c a r e and p a t i e n c e .

BORIYG TOOLS The t o o l p o s t of t h e home made l a t h e w i l l hold a 114" forged b o r i n g t o o l i n i t s s l o t . When extended a s much a s 2 112" t o 3", t h e t o o l i s v e r y f l e x i b l e and t h e r e i s much t e n d e n c y f o r i t t o s p r i n g away from t h e work. The s u p p o r t a t t h e t o o l p o s t and t h e form and c o n d i t i o n of t h e c u t t i n g edge w i l l h a v e a g r e a t e f f e c t . Much time can be saved by g r i n d i n g t o p r o p e r form and honing t o a r a z o r s h a r p edge.

The photo shows t h e column base c a s t i n g beinp, bored w i t h t h e t o o l mounted i n t h e t o o l p o s t w i t h o n l y washers f o r s u p p o r t . When I added t h e simple V block t o s u p p o r t t h e t o o l 1 w a s a b l e t o make d e e p e r c u t s w i t h each p a s s and was much

You can buv forcer1 bori.7,: L o u t s but thev a r e q u i t e exp e n s i v e a t 5 6 . 0 0 t o 5 7 . 0 0 each. 1 36" l e n g t h o i l / 4 " d r i l l rod w i l l make a h a l f dozen o r more f o r l e s s t h a n t h e p r i c e of one. There i s l i t t l e p o i n t i n making a 1 / 4 " b o r i n g t o o l any l o n g e r t h a n 5" o r 6 " because t h e y a r e n o t r i g i d enough f o r deep h o l e b o r i n g . I t ' s a simple m a t t e r t o h e a t t h e end of t h e rod t o a b r i g h t r e d h e a t and f o r g e a s h o r t hook. You h e a t it t o a b r i g h t r e d a g a i n and quench i t i n o i l o r w a t e r t o hardThen you p o l i s h t h e hardened end w i t h emery and en i t . h e a t i t u n t i l i t t u r n s a l i g h t s t r a w c o l o r and quench i t t o temper i t . Commercially made b o r i n g t o o l s a r e hardened and temp e r e d f o r t h e e n t i r e l e n g t h , and t h a t makes a more r i g i d t o o l , b u t i t i s d i f f i c u l t t o do w i t h o u t a m u f f l e f u r n a c e t o h e a t t h e e n t i r e t o o l e v e n l y . I harden and temper only t l ~ cr;or: l s .

24

The conventional boring t o o l i s bent t o a s h o r t hook and ground t o a form much l i k e a t u r n i n g t o o l .

Such a t o o l works very w e l l , b u t i t won't e n t e r t h e small s t a r t i n g h o l e t o f i n i s h a bore a t l e s s than about 314". A s m a l l e r t o o l i s made by h e a t i n g t h e e n d t o b r i g h t red and s w e l l i n g it w i t h a few blows of t h e hammer. A f t e r hardening and tempering, i t i s ground t o a " D " shape and given t h e proper angle and c u t t i n g edge. Such a t o o l w i l l e n t e r a s m a l l s t a r t i n g h o l e , and i t w i l l work very w e l l on l a r g e bores t o o .

BORING TECHNIQUE Learning t o b o r e p r e c i s e l y r e q u i r e s study and p a t i e n c e . The s l i g h t e s t e r r o r i n t o o l form o r s e t up can make a g r e a t d e a l of d i f f e r e n c e . Mysterious t h i n g s may happen i n your e a r l y experience, but they w i l l be found t o have a simple explanation. Given t h e p r o p e r formand s e t u p , t h e t o o l w i l l c u t w e l l o n l y i f i t has a v e r y keen edge. That r e q u i r e s wet honing t o r a z o r s h a r p n e s s i n a d d i t i o n t o g r i n d i n g t o form. The c u t t i n g edge must b e o n t h e c e n t e r l i n e o f t h e bore f o r a c c u r a t e l y p r e d i c t a b l e c u t s . I f it i s aboveorbelow c e n t e r t h e c u t w i l l be deeper than p r e d i c t e d .

The c u t t i n g edge needs a s l i g h t amount of " r a k e " t o c u t p r o p e r l y . That means t h e t o p s u r f a c e of t h e t o o l i s slanted. I f the rake i s too s l i g h t t h e c u t t i n g action i s poor a n d t h e edge i s q u i c k l y blunted. I f t h e r a k e i s t o o g r e a t t h e t o o l w i l l c h a t t e r and produce a rough c u t .

2 TO 4 DEGREES OF RAKE

, n

The c u t t i n g e d g e n e e d s " r e l i e f " f o r c l e a r a n c e below t h e c u t t i n g edge. I f t h e r e i s n o t e n o u g h r e l i e f t h e e f f e c t i s s i m i l a r t o n o t enough t o p r a k e : Poor c u t t i n g a c t i o n , i f any, and t h e t o o l i s q u i c k l y b l u n t e d . Too much r e l i e f causes c h a t t e r and a rough c u t . I t c a n t a k e s e v e r a l evenings of s t u d y and p r a c t i c e t o I t w i l l be worth l e a r n how t o g r i n d and sharpen t o o l s . your while t o p r o v i d e a couple of e x t r a c a s t i n g s f o r pract i c e s o t h a t you can master t h i s simple s k i l l . PREDICTING THE FINISHED SIZE OF THE BORE E a c h o f t h e r e q u i r e d bores w i l l need t o b e f i n i s h e d t o anexactsizesomatingpartswill f i t without p l a y . Since t h e home made l a t h e l a c k s graduated c o l l a r s on t h e feed screws, t h i s may seem t o be an impossible c h o r e . A c t u a l l y , graduated c o l l a r s would be of l i t t l e v a l u e i f you had them. The g r a d u a t i o n s only p r o v i d e an a c c u r a t e e s t i m a t e of t h e d e p t h of c u t , and they a r e n o t a b l e t o t a k e i n t o conside r a t i o n t h e y i e l d of t h e t o o l and t h e work. You can e s t lmate j u s t a s w e l l without g r a d u a t i o n s . A c t u a l l y , t h e r e a r e c l e a r g r a d u a t i o n s even though you have no markings on t h e c o l l a r . Since one f u l l t u r n of t h e feed screw w i l l a d v a n c e t h e t o o l a p r e d i c t a b l e amount, then a f r a c t i o n of a t u r n i s a l s o p r e d i c t a b l e . I t i s easy t o n o t e t h e p o s i t i o n o f t h e feed handle and r o t a t e i t j u s t one h a l f t u r n , and j u s t a s easy t o r o t a t e i t j u s t one quarter. This g i v e s you f o u r reasonably a c c u r a t e d i v i s i o n s i f you know how much t h e t o o l i s advanced w l t h a f u l l t u r n of t h e screw. I t does n o t t a k e long t o l e a r n t o d i v i d e t h e q u a r t e r t u r n s i n t o y e t s m a l l e r increments s o you can p r e d i c t a c u t of a s l i t t l e a s .002" with amazing accuracy. 26

We've d i s c u s s e d i t i n e a r l i e r manuals, but i t can be an e l u s i v e p r o c e s s o f t h o u g h t u n t i l i t i s w e l l understood. We'll review i t h e r e i n c a s e you s t i l l oeed a l i t t l e h e l p . You need only know t h e p i t c h o f t h e feed screw and you know how much t h e t o o l i s advanced with one t u r n of t h e screw. I t r e q u i r e s 20 t u r n s of t h e screw t o advance t h e t o o l one f u l l inch on t h e home made l a t h e . That means i t i s a 2 0 p i t c h screw, and one f u l l t u r n moves t h e t o o l one t w e n t i e t h of an i n c h . Other l a t h e s may have 8, 10, o r 16 p i t c h screws, and you can e a s i l y f i n d o u t by counting t h e number of t u r n s t h a t move t h e t o o l one inch. Then apply t h e f r a c t i o n t o determine t h e amount of feed f o r one t u r n . Convert t h e f r a c t i o n t o a decimal number t o d e t e r m i n e how many t h o u s a n d t h s o f a n i n c h each t e r n r e p r e s e n t s . On t h e home made l a t h e 1 / 2 0 " i s e q u a 1 t o . 0 5 0 " . ( One d i v i d e d by twenty. ) One h a l f t u r n r e p r e s e n t s .025", one f o u r t h t u r n r e p r e s e n t s .0125", and one e i g h t h t u r n r e p r e s e n t s ,00625". Keep i n mind t h a t t h e s e f i g u r e s r e p r e s e n t t h e t r a v e l o f t h e t o o l , n o t t h e d e p t h of c u t . A s you a r e moving t h e t o o l on t h e r a d i u s o f t h e c u t t i n g c i r c l e , t h e e f f e c t w i l l be twice a s g r e a t on t h e d i a m e t e r . On t h e home made l a t h e and one f o u r t h of a t u r n w i l l advance t h e c u t t e r .0125" i t w i l l change t h e d i a m e t e r by .025". For l a t h e work, i t i s n e c c e s s a r y t o reason i n terms of depth of c u t r a t h e r than t h e amount of t o o l t r a v e l . Whether o r n o t t h e screw h a s g r a d u a t i o n s on t h e coll a r , t h e p r e d i c t e d depth of c u t i s p u r e l y t h e o r e t i c a l . I t d o e s n o t t a k e i n t o c o n s i d e r a t i o n t h e y i e l d of t h e t o o l o r the work p i e c e , and t h e measured r e s u l t w i l l n o t be what was i n d i c a t e d i n m o s t c a s e s . I n a c t u a l p r a c t i c e you w i l l make a s e r i e s of c u t s t o c l e a n up t h e work. Then you adv a n c e t h e c u t t e r t o make a t h e o r e t i c a l c u t of .025". You measure t h e work a f t e r t h e c u t t o f i n d t h a t you changed This means t h a t t h e t o o l o r t h e diameter by only .023". the workpiece, o r both, y i e l d e d by .002". An a d d i t i o n a l pass a t t h e same s e t t i n g may b r i n g t h e work t o s i z e , o r you may have t o advance t h e c u t t e r an a d d i t i o n a l amount t o compensate f o r y i e l d on t h e second p a s s . The d i f f e r e n c e between t h e t h e o r e t i c a l c u t and t h e act u a l c u t i s m u c h g r e a t e r w i t h t h e small forged boring t o o l because i t l a c k s f i r m s u p p o r t n e a r t h e c u t t i n g edge. You measure t h e bore b e f o r e and a f t e r each p a s s t o lea'rn t h e exact amount t h a t w i l l be c u t a t any t h e o r e t i c s e t t i n g of the c r o s s f e e d .

L e t ' s d i s c u s s a p r a c t i c a l job t o d e m o n s t r a t e t h e p r i n c i p l e s involved. A 1" X 8" a r b o r w i l l beneeded formachi n i n g some of t h e p a r t s f o r t h e d r i l l p r e s s . I t must be a t r u l y round a r b o r t h a t r u n s c o n c e n t r i c w i t h t h e a x i s o f t h e l a t h e , and i t s d i a m e t e r should be no more than 1" and no s m a l l e r than .001" u n d e r s i z e . The l e n g t h i s n o t c r i t i c a l . You could n o t p o s s i b l y l o c a t e and d r i l l t h e t u r n i n g c e n t e r s p r e c i s e l y o n a 1" s h a f t , s o you must begin ~ i t ha l a r g e r s h a f t and t u r n i t t o dimension between c e n t e r s on the lathe. An 8" l e n g t h o f l 118" o r 1 114" cold r o l l e d s t e e l i s prepared w i t h 60 degree c e n t e r s i n each end, and i t ' s mounted between c e n t e r s w i t h a dog t o d r i v e i t . I t w i l l n o t be p e r f e c t l y c e n t e r e d , s o o n e ormore pass e s w i l l have t o be made t o b r i n g t h e s h a f t c o n c e n t r i c . Nothing about t h e a c t u a l c u t t i n g d e p t h can be determined from t h e s e " c l e a n i n g up " p a s s e s , b u t y o u c a n m e a s u r e t h e c l e a n e d u p d i a m e t e r a t b o t h e n d s t o s e e i f your c e n t e r s a r e p r o p e r l y a l i g n e d . I f o n e e n d i s l a r g e r t h a n t h e o t h e r , you must a d j u s t t h e t a i l s t o c k s e t over t o b r i n g t h e t u r n i n g axis parallel t o the tool travel. You can only machine from 213 t o 314 of t h e l e n g t h of t h e s h a f t because t h e dog t a k e s up s p a c e o n t h e end. The work w i l l be t u n e d end f o r end and remounted t o machine t h e remaining l e n g t h when t h e f i r s t p o r t i o n i s f i n i s h e d . You w i l l need a micrometer o r a v e r n i e r c a l i p e r s f o r p r e c i s e measuring. My own p r e f e r e n c e i s t h e v e r n i e r c a l i p e r s because it measures both i n s i d e and o u t s i d e , and a s i n g l e t o o l covers a wide range of s i z e s . You can g e t a n i c e s t a i n l e s s s t e e l one form Wholesale Tool Co. f o r l e s s than $20.00. When t h e s h a f t i s cleaned up, a n d o f uniform diameter from end t o end, you can measure i t t o e s t a b l i s h t h e s t a r t i n g dimension. L e t ' s say you began w i t h a 1 114" diame t e r , which i s 1.25O0, and i t cleaned up a t 1.205". You must reduce i t by an a d d i t i o n a l .205" t o f i n i s h a t 1.00". The p o s i t i o n o f t h e feed screw handle now becones t h e r e f e r e n c e , and i t i s e a s i e s t t o j u d g e i t when i t i s e i t h e r i n a v e r t i c a l o r h o r i z o n t a l p o s i t i o n . Then it i s easy t o t u r n i t one q u a r t e r t u r n from h o r i z o n t a l t o b r i n g i t v e r t i c a l , o r one q u a r t e r t u r n from v e r t i c a l t o b r i n g i t horizontal. The o b j e c t now i s t o make a p a s s a t a s e t t i n g t h a t w i l l f i n i s h a t some even m u l t i p l e of .025" with t h e feed handle i n e i t h e r t h e v e r t i c a l o r h o r i z o n t a l p o s i t i o n . L e t ' s say t h a t t h e handle was e x a c t l y v e r t i c a l when

you made t h e l a s t cleaning up p a s s . The cleaned up dimension i s 1.205", and i f you advanced t h e t o o l 114 t u r n t o remove an a d d i t i o n a l .025", t h e t h e o r e t i c dimension a f t e r t h e pass w i l l be 1.180". I f you t r y t o e s t i m a t e a f r a c t i o n a l t u r n of t h e handle t o f i n i s h a t 1.175" i t w i l l n o t be e x a c t l y h o r i z o n t a l , andyou won't have a n a c c u r a t e r e f erence p o i n t . This i s where thecompound feed screw g e t s into the act. The compound feed screw on t h e mome made l a t h e has t h e same p i t c h as t h e c r o s s feed screw, but because i t i s s e t a t a n a n g l e t o t h e work it d o e s n ' t change t h e depth of c u t as much p e r t u r n . Turn t h e c r o s s feed screw 114 t u r n t o h o r i z o n t a l , and turn t h e compound screw about 1/16 t u r n and make a t r i a l pass. Measure t h e r e s u l t t o s e e how closeyoucame t o t h e t h e o r e t i c 1.175". Always t u r n o f f t h e l a t h e and wait f o r t h e work t o s t o p before you make any measurement. I f you f i n i s h e d t h e t r i a l p a s s a t something l i k e 1.177" i t i s only neccessary t o advance t h e compound a v e r y t i n y amount tocome t o an even dimension. I f you f i n i s h e d a t near 1.173" t h e compound must be backed up. There i s always a small amount c f end play i n a feed screw, and when you need t o back i t up you must move i t enough t o t a k e up t h e end play and an a d d i t i o n a l amount t o back up t h e t o o l . Maybe t h e n e x t pass w i l l f i n i s h up a t 1.151". so j u s t advance t h e c r o s s feed 114 t u r n and advance t h e compound a very t i n y amount t o attempt t o f i n i s h t h e next pass a t exactly 1.125". You s t i l l h a v e a t l e a s t f o u r more chances t o g e t i t r i g h t before t h e f i n a l p a s s . By t h e s e t r i a l s you w i l l l e a r n t o judge t h e depth of cut very a c c u r a t e l y , and you w i l l be making adjustments i n " teeny b i t s ", " t a d s ", " smidgeons ", and such terms t h a t might seem a d i s g r a c e t o some, but You can work t o a tolerance o f p l u s orminus .OOl"without graduated c o l l a r s , and they c a n ' t . The same method a p p l i e s t o boring, but m u l t i p l e pass e s asemade oneach s e t t i n g . You must measure a f t e r each pass a n d l e a r n t h e e f f e c t of each s e t t i n g . I t can t a k e a s many as f i v e o r s i x p a s s e s t o make a t h e o r e t i c c u t of .025" i n aluminum, and even more i n s t e e l . L e t ' s say you nave cleaned up t h e bore of t h e column base c a s t i n g a t 1.525", and you want t o e n l a r g e it t o t h e s i z e of t h e column, which i s 1.650". That's .125"tobe 29

removed, s o y o u h a v e p l e n t y ofroom t o work with before t h e f i n a l pass. Advance t h e screw 114 t u r n f o r a c u t of .025" and make one pass t o t h e bottom of t h e bore and withdraw t h e carriage. Measure t h e bore c a r e f u l l y , and you w i l l l i k e l y find t h a t you have only removed about .012" because t h e s l e n d e r t o o l s p r i n g s away from t h e work. Make asecond pass without changing t h e s e t t i n g o f t h e screw, and you w i l l probably have removed an a d d i t i o n a l .006". A t h i r d pass may remove .004", a f o u r t h pass .OO2", and a f i f t h pass .001". A s e r i e s o f t r i a l passes with c a r e f u l measurement aft e r each pass w i l l teach you what t o expect, and t h i s must be learned with each n e w s e t u p because t h e t o o l w i l l not perform i n t h e same way when t h e s e t up i s changed. Once you have e s t a b l i s h e d t h e s e t t i n g and determined t h e number of passes f o r a given s e t up t h e r e i s no need t o measure a f t e r any but t h e l a s t pass of each s e t t i n g . The only p r e c i s i o n t o o l I ' v e used i n building my own shop i s a $13.00 v e r n i e r c a l i p e r s t h a t enables me t o meaI h a v e n ' t p u t graduations on any of my s u r e t o .001". feed screw c o l l a r s because I simply d o n ' t need them. I g e t s a d i s t i c p l e a s u r e out of machining a piece t o within . 0 0 l W , and then handing i t t o t h e b i r d who says i t simply c a n ' t be done. DON'T GIVE UP Many of t h e o p e r a t i o n s i n building t h e s e p r o j e c t s a r e t e d i o u s and time consuming, and i t ' s easy t o g e t discouraged. Speed and s k i l l come with p r a c t i c e though, and you simply c a n ' t acquire them i n any easy way. I h a d t o mold my l a t h e bed s i x times before I got two I would have good c a s t i n g s , and I ' m not a p a t i e n t man. stopped then i f i t w e r e n o t f o r t h e commitment t o w r i t e t h i s s e r i e s o f m a n u a l s , because1 r e a l l y d i d n ' t want a l a t h e as much as I thought I d i d when I began. A l l of my machines a r e f i n i s h e d now, and I have a p r o j e c t l i s t ahead with no end i n s i g h t . I ' m glad I d i d n ' t q u i t . Many ofmy f u t u r e p r o j e c t s a r e items I would have f e l t beyond me when I began t h i s s e r i e s . Having t h e machines helpsmakethempossible, but, more important, I ' v e learned how t o solve problems. That r e a l l y i s t h e most valuable p a r t of t h e whole experience. 30

CHAPTER I11

THE COLUMN AND BASE

Themain f e a t u r e of a d r i l l p r e s s t h a t makes i t s o v a l uable i s i t s a b i l i t y t o d r i l l a t r u l y perpendicular hole e x a c t l y where you want i t . E x t r a c a r e must b e t a k e n t o b e s u r e t h a t t h e b a s e and t a b l e a r e a t r i g h t a n g l e s t o t h e column, and t h a t t h e q u i l l and s p i n d l e a r e p a r a l l e l t o t h e column.

DRESSIVG THE COLUMW

The columnof a c o m m e r c i a l l y b u i l t d r i l l p r e s s w i l l be a c c u r a t e l y machined and ground t o a h i g h f i n i s h , and t h i s job would b e b e y o n d t h e r a n g e o f m o s t home shops. By u s i n g V block clamps i n s t e a d of t h e c o n v e n t i o n a l bored clamps we can t o l e r a t e a column t h a t i s n o t t r u e round and uniform i n f i i a m e t e r over i t s e n t i r e l e n g t h . Ordinary w a t e r p i p e -

w i l l d o t h e job, and it i s o n l y neccessary t o f i l e t h e s u r f a c e and p o l i s h i t with emery c l o t h o r sand paper. I ' v e u s e d s t a n d a r d w e i g h t p i p e f o r my d r i l l p r e s s , but you c a n g e t e x t r a h e a v y pipe f o r a s t r o n g e r column. I t i s t h e same o u t s i d e diameter, b u t t h e wall t h i c k n e s s i s about 113 g r e a t e r . I n o t e a s l i g h t d e f l e c t i o n of t h e column on my d r i l l p r e s s when d r i l l i n g l a r g e h o l e s i n s t e e l , though i t would o n l y b e a s e r i o u s p r o b l e m i n v e r y high c l a s s work. Youshouldconsider e x t r a heavy pipe i f you plan on much heavydutywork. Black pipe i s much e a s i e r t o p o l i s h than galvanized. As d e t a i l e d i n t h i s m a n u a l , t h e column i s 1 114" pipe. You c a n u s e l a r g e r p i p e f o r your column, but then you must e n l a r g e t h e column base and re-design t h e clamps f o r t h e head and work t a b l e . The clamps a r e designed t o c o n t a c t t h e c o l u m n a t o p p o s i n g p o i n t s , and t h e V should be broadened f o r l a r g e r p i p e . There i s n o reason why you c a n ' t use a t a l l column and a l a r g e r base t o b u i l d a f l o o r model. I f you do, I suggest a 2" e x t r a heavy pipe column and a l a r g e r base. You can use 114" X 2" angle t o frame t h e base, w i d e n i t t o 12 314" a n d u s e t h r e e s l a b s o f 114" X 3" cold r o l l e d s t e e l f o r t h e Move top s u r f a c e with two s l o t s , and make i t 18" deep. t h e column base about 4" forward of t h e r e a r edge of t h e Add base f o r b e t t e r balance, and b o l t it t o t h e f l o o r . a b r a c e m a d e o f a n g l e i r o n bolted t o t h e underside t o span t h e top i r o n s . Dressing thecolumn i s a simple job i f you have a l a t h e with enough c a p a c i t y between c e n t e r s . You would j u s t mount i t with a p a i r of p i p e c e n t e r s , draw f i l e i t and p o l i s h up with emery c l o t h o r sand paper. I n t h e p a s t I ' v e done t h e job on a wood l a t h e by preparing a p a i r of hardwood c e n t e r s which I drove i n t o t h e ends o f t h e p i p e t o mount i t on wood t u r n i n g c e n t e r s . I t i s extremely dangerous and should n o t be done. I f oneof t h e wooden c e n t e r s breaks o r s l i p s o f f , t h e pipe becomes a deadly m i s s i l e . When spinning work l e a v e s t h e l a t h e c e n t e r s , i t w i l l e i t h e r miss you and s c a r e y o u n e a r t o death, o r i t w i l l h i t you and k i l l you. I t i s n o t l i k e l y t o be a minor i n j u r y a t b e s t . Having been f o r t u n a t e enough t o only be scared h a l f t o d e a t h , I devised a s a f e r method. I t ' s a s i m p l e arbor mountedon a p a i r of p i l l o w blocks, and you a r e l i k e l y t o h a v e most of what you need on hand. The s h a f t and themotor a t l e a s t w i l l be used t o build t h e d r i l l p r e s s , and t h e remainder amounts t o l i t t l e c o s t .

The base i s 3/14" plywood, and t h e s u p p o r t s f o r t h e p i l low b l o c k s a r e 6" l e n g t h s of 2" X 4" lumber. The s u p p o r t s a r e glued a n d n a i l e d t o t h e b a s e , and t h e p i l l o w b l o c k s a r e mounted w i t h 114" c a r r i a g e b o l t s t h a t p a s s through t h e base and t h e s u p p o r t s . Lag b o l t s w o u l d n o t be s a f e because t h e wooden s u p p o r t s could break away.

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' 1 ' ' 1 ' p i e c e of i / ' i " ~plv!;oo I w a s n ihlc i i o r thr? mot o r mount, and a n o t h e r m a l l p i e c e was added t o t h e oppos i t e end s o i t would r e s t e v e n l y on t h e bench.

I purchased a 36" l e n g t h of 518" cold r o l l e d s h a f t , h a l f of which became t h e s p i n d l e f o r t h e d r i l l p r e s s . A P a i r of 518" s e t screw c o l l a r s t a k e up end p l a y . I b o r r o w e d t h e 7 " p u l l e y f r o m t h e shapers c o u n t e r s h a f t , and used a 2" p u l l e y on t h e 1725 RPM motor t o g i v e aworki n g speed of l e s s than 500 RPM. The 1 114" p i p e i s prepared f o r mounting by d r i l l i n g f o u r 114" h o l e s 318" from each end and rapping them 5116"1 8 f o r t h e a d j u s t i n g screws. This p r o v i d e s ameans t o adj u s t t h e p i p e t o n e a r c e n t e r on t h e s h a f t . 518" SHAFT

m /

I t does n o t have t o be p e r f e c t l y c e n t e r e d , and i t ' s n o t d i f f i c u l t t o b r i n g it v e r y c l o s e t o t r u e . There i s d a n g e r from t h e s p i n n i n g screws because they become n e a r l y i n v i s i b l e i n motion. They can t a k e o f f a k n u c k l e o r a whole f i n g e r i n a f l a s h . Don't go n e a r such a monster wearing a n e c k t i e , long s l e e v e s , o r l o o s e f i t t i n g c l o t h i n g of any kind. 2 6 " t o 2 8 " makes a p r a c t i c a l h e i g h t f o r a bench d r i l l p r e s s . One i n c h on each end w i l l be wasted when you c u t away t h e tapped h o l e s . T h e r e i s a p r o t e c t i v e c o a t i n g on black p i p e t h a t w i l l clog up your f i l e , s o d r e s s i t up w i t h c o a r s e sand paper b e f o r e you b e g i n t o f i l e . Use a l a r g e s i n g l e c u t f i l e of a t l e a s t 1 2 " l e n g t h . 14" o r 16" i s even b e t t e r . Don't allow t h e f i l e t o r i d e t h e work, but move it a s though i t were held s t a t i o n a r y i n t h e v i s e . L i f t it on t h e back s t r o k e s o y o u d o n ' t wear o u t t h e t e e t h . Make a s e r i e s of d i a g o n a l c u t s along t h e e n t i r e l e n g t h t o keep t h e diameter u n i f o m . I t ' s n o t p o s s i b l e t o b r i n g i t t r u e round, and t h e o n l y o b j e c t i s t o remove t h e s c a l y s u r f a c e and d r a s t i c h i g h a r e a s toimprove i t s s u r f a c e a b i t . The whole opera t i o n only t a k e s 10 o r 15 minutes, and you can f i n i s h by p o l i s h i n g w i t h c o a r s e emery c l o t h o r sand p a p e r .

When i t i s d r e s s e d and p o l i s h e d you w i l l have removed only .002" o r .003" of m a t e r i a l from t h e h i g h a r e a s . You c a n c u t p a r t l y t h r o u g h t h e s p i n n i n g p i p e w i t h a hack saw about 1" from each end. Be v e r y c a r e f u l of t h e s p i n n i n g b o l t s , a n d d o n ' t c u t more t h a n about 314 through. F i n i s h c u t t i n g o f f t h e ends w i t h t h e column h e l d i n t h e vise.

THE COLUMN BASE CASTING T h i s p a t t e r n w i l l be e a s y t o make i f you d r i l l a p a i r of d i a g o n a l l y o p p o s i t e h o l e s i n t h e f l a n g e and mount i t on t h e l a t h e f a c e p l a t e t o b o r e t h e t a p e r e d h o l e and f i n i s h t h e c i r c u l a r p a r t . When i t ' s f i n i s h e d j u s t f i l l t h e h o l e s with body p u t t y . I t r e q u i r e s o n l y minimum d r a f t o n t h e o u t s i d e s u r f a c e s , but t h e b o r e t a p e r s from 1" d i a m e t e r a t t h e b a s e t o 1 1/2" a t t h e t o p s o i t w i l l l e a v e a c l e a n g r e e n sand c o r e i n t h e

FACE PLATE

----j

BORE TAPER

This i s a r o u t i n e mold, f e d with a 1 114" s u r u e a t a n y s i d e . Press t h e c o r e a r e a f u l l of sand with your f i n g e r s as you f i l l t h e d r a g , but d o n ' t ram i t any t i g h t e r than t h e mainbody o f t h e d r a g . I f t h e c o r e i s rammed t o o t i g h t i t w i l l n o t y i e l d when you r a p t h e p a t t e r n , but w i l l break away and l i f t out when you draw t h e p a t t e r n . I t must be r e s i l i e n t enough t o y i e l d when you rap, but f i r m e n o u g h t o Take e x t r a r e t a i n i t s shape when t h e p a t t e r n i s drawn. c a r e t o c l e a n up t h e c a v i t y t o avoid any sand i n c l u s i o n s i n t h e c a s t i n g . Swab t h e g a t e , b o t h t o p and bottom of t h e sprue opening, and any weak a r e a s a t t h e edge of t h e core.

MACHINING THE COLUMN BASE CASTING I f you a r e n o t s k i l l e d a t boring on t h e l a t h e , you w i l l be when you have f i n i s h e d t h i s c a s t i n g . Don't be u p s e t i f youhave t o s p e n d two o r t h r e e evenings a t i t . Forget, f o r now, t h a t you a r e b u i l d i n g a d r i l l p r e s s . J u s t use as much time as you need t o l e a r n how t o machine t h i s one p a r t . Don't work l a t e u n t i l you a r e b l e a r y eyed and t e n s e . I t ' s n o t a bad i d e a t o make two c a s t i n g s , o r even t h r e e , s o you w i l l have another on hand i n c a s e you s p o i l one by boring o v e r s i z e . Nothing w i l l be l o s t b u t a l i t t l e time, and you w i l l g a i n a valuable s k i l l . The column w i l l n o t be p e r f e c t l y round, s o you must determine its average diameter and bore t o .001" over t h e average s i z e . C a r e f u l l y measure t h e diameter o f t h e c o l urn a t s e v e r a l p l a c e s around it t o determine t h e l a r g e s t and s m a l l e s t dimension. Mine measures 1.662" a t t h e small e s t a n d 1 . 6 6 7 " a t t h e l a r g e s t , so i t i s .005" out o f r o u n d . I expected worse, s o I was p l e a s e d . I bored t h e base t o 1.665", which i s j u s t o n e h a l f thousandth o v e r t h e a v e r a g e , and i t was j u s t a b i t t o o snug when I drove i t onto t h e I needed no s e t screws t o lock t h e column, but column. you could add one o r more s e t screws i f you bore j u s t a b i t too loose. You could mount t h e c a s t i n g with spacers and bore i t a l l t h e way through, butyou w i l l be more c e r t a i n t h a t t h e column i s e x a c t l y perpendicular t o t h e base i f you mount d i r e c t l y t o t h e f a c e p l a t e and bore t o a 118" shoulder a t t h e bottom of t h e hole. D r i l l f o u r 114" h o l e s i n t h e f l a n g e , b u t t a p j u s t two The tapped holes of them d i a g o n a l l y o p p o s i t e 5116"-18. w i l l be used t o mount i t on t h e f a c e p l a t e , and a l l four w i l l be used a s a guide t o d r i l l t h e t a p h o l e s i n t h e b a s e

36

later. Then t h e base i s tapped 5116"-18, and t h e h o l e s i n t h e c a s t i n g a r e enlarged t o 5/16" f o r t h e b o l t s . The f i r s t o p e r a t i o n i s t o f a c e o f f t h e bottom, s o b o l t i t t o t h e f a c e p l a t e w i t h s e t screw c o l l a r s o r bushings of equal l e n g t h f o r s p a c e r s .

TAP 5116"-18 SPACERS The o b j e c t h e r e i s t o machine t h e bottom t r u e f l a t s o You can use a s t a c k of s e t screw c o l l a r s and f l a t washers f o r spacers, o r a p a i r of bushings o r s l e e v e s of equal l e n g t h , s o t h a t t h e bottom s u r f a c e w i l l b e p a r a l l e l t o t h e f a c e p l a t e . Center i t on t h e f a c e p l a t e reasonably c l o s e , f a c e o f f t h e A ; bottom s u r f a c e , and e n l a r g e t h e bore t o about 1 318". ' 118" shoulder w i l l be l e f t a t t h e bottom of t h e bore, s o +i there i s no need t o be p r e c i s e a t t h i s p o i n t . T e s t t h e faced o f f s u r f a c e w i t h a good s t r a i g h t edge : t o be s u r e i t i s t r u e f l a t , then mount t h e machined s u r , face on t h e f a c e p l a t e without s p a c e r s . Center t h e outside diameter of t h e c i r c u l a r p o r t i o n w e l l s o t h a t t h e w a l l thickness of t h e boss w i l l be uniform a f t e r boring.

i t w i l l mount f i r m l y f o r t h e boring o p e r a t i o n .

i 1

a

-

LEAVE 118" SHOULDER

FACE OFF

Face o f f t h e end of t h e c i r c u l a r p o r t i o n , then proceed You t o c l e a n up t h e bore t o w i t h i n 118" of t h e bottom. can make one o r more groups of p a s s e s a t a c u t t i n g d e p t h of .050" u n t i l t h e b o r e i s c l e a n e d u p , but reduce t h e d e p t h t o .025" when you a r e w i t h i n .loo" of f i n i s h e d s i z e . Use n o t e s t o k e e p t r a c k of what you a r e doing, and measure a s many t i m e s a s you need t o t o g e t c o n s i s t e n t r e a d i n g s with your c a l i p e r s . When you can g e t t h e same r e a d i n g two o r t h r e e times i n a row you a r e doing i t r i g h t . Ultimate succ e s s depends almost e n t i r e l y on your a b i l i t y t o measure accurately. You can make a simple V block t o support and s t i f f e n t h e b o r i n g t o o l f r o m 118" X 114" key s t o c k . Cut a s h a l l o w Clamp groove i n each of two blocks with t h e hack saw. them t o g e t h e r i n t h e v i s e and s t e p d r i l l through t h e cent e r t o a b o u t 7/32". Then f i l e t h e h a l f h o l e t o a V shape. I h a d t o f i l e a shallow notch i n t h e u n d e r s i d e of mine t o c l e a r t h e lower edge of t h e s l o t i n my t o o l p o s t . CLAMP TOGETHER

\

SAW CUTS

I

I

Zd

BORING TOOL

FILE NOTCH

I

-TOOL

POST

BLOCK

Usual p r a c t i c e i s t o clamp t h e t o o l with two b l o c k s , one on t h e bottom and t h e o t h e r on t o p . The s l o t i n my t o o l p o s t i s n o t deep enough f o r both blocks, b u t t h e one block s u p p o r t i n g t h e l o w e r s u r f a c e of t h e b a r s t i f f e n s i t greatly. Measure t h e h e i g h t o f t h e t a i l c e n t e r and s e t t h e cuti n g e d g e o f t h e t o o l a t t h e same h e i g h t . Extend t h e t o o l j u s t s l i g h t l y more than enough t o r e a c h t h e b o t t o m o f t h e bore. Hone t h e t o o l t o r a z o r sharpness, w i t h a t i n y r a d i u s a t t h e nose.

The i n t e n t i o n i s t o b o r e t h e c a s t i n g t o a f o r c e d f i t on t h e column. The f o u r h o l e s i n t h e f l a n g e w i l l be t h e t e m p l a t e f o r d r i l l i n g t h e t a p h o l e s i n t h e mounting b a s e , s o you should b u i l d t h e b a s e and f i t t h e c a s t i n g t o i t bef o r e you d r i v e i t o n t o t h e column. Clamp t h e c a s t i n g t o t h e assembled b a s e , d r i l l one 1/4" h o l e i n t h e b a s e t h r o u g h one of t h e h o l e s i n t h e c a s t i n g , Enlarge t h e s e p a r a t e t h e p a r t s and t a p t h e b a s e 5/16"-18. h o l e i n t h e c a s t i n g t o 5/16", and b o l t i t t o t h e base t o d r i l l t h e r e m a i n i n g t a p h o l e s i n t h e b a s e assembly. Then t a p t h e remaining h o l e s , e n l a r g e h o l e s i n t h e c a s t i n g , and make a t r i a l assembly w i t h a l l f o u r b o l t s . When t h e c a s t i n g i s f i t t o t h e base you can d r i v e i t o n t o e i t h e r end o f t h e column. R e s t t h e column on a block of hardwood, a n d u s e a n o t h e r b l o c k t o p r o t e c t t h e c a s t i n g a s y o u d r i v e i t on w i t h a one o r one and a h a l f pound hammer. F i n a l l y , b o l t t h e column b a s e c a s t i n g t o t h e mounting base w i t h f o u r 5116"-18 X 1" c a p s c r e w s w i t h l o c k w a s h e r s .

THE MOUNTING BASE My o r i g i n a l p l a n w a s t o p r e s e n t t h e d e s i g n w i t h a c a s t aluminum b a s e . A f t e r c a s t i n g i t a n d d o i n g p r e l i m i n a r y w o r k on i t , I r e a l i z e d t h a t i t was t h e machining of t h e c a s t i n g t h a t would be a s e r i o u s problem i n t h e d e v e l o p i n g shop. The f a b r i c a t e d mounting base i s t h e more p r a c t i c a l i d e a a t this point. The e n t i r e assembly i s shown a s b o l t e d t o g e t h e r w i t h 114"-20 X 1 / 2 " cap screws w i t h l o c k washers, b u t it c a n b e welded i f you have t h e equipment. I used 114" X 3" c o l d r o l l e d s t e e l f o r t h e t o p , b u t I hot r o l l e d s t e e l would work almost a s w e l l . Dimensions a r e n o t c r i t i c a l , b u t o f c o u r s e t h e s l o t should be c a r e f u l l y spaced, t h e assembly should be w e l l squared, and i t must r e s t f i r m l y on a f l a t s u r f a c e s o i t won't be t w i s t e d when b o l t e d t o t h e bench t o p . As i n a l l s t a c k e d a s s e m b l i e s u s i n g rows of screws t o I join them, i n s t a l l o n e b o l t c o m p l e t e l y b e f o r e d r i l l i n g t h e remaining h o l e s . Only t h e f r o n t member of t h e frame i s n o t c h e d t o a d m i t t h e h e a d of a c a r r i a g e b o l t f o r mounting work on t h e b a s e . Clamp t h e t o p p l a t e s t o t h e f r o n t and back a n g l e s w i t h a l e n g t h of 318" key s t o c k between them t o s p a c e f o r t h e s l o t . Then d r i l l t a p s i z e h o l e s t h r o u g h b o t h members t o

;

i

begin c o n s t r u c t i o n . Tap t h e h o l e s i n t h e t o p members, and e n l a r g e t h e h o l e s i n t h e a n g l e s t o 114". I n s t a l l thecap screws through t h e bottom. Square up t h e assembly a s you l o c a t e and i n s t a l l t h e screws through t h e f r o n t andback a n g l e s , then i n s t s l l t h e s i d e a n g l e s p a r a l l e l t o each o t h e r . I n s t a l l one of t h e mounting f e e t completely, but ins t a l l t h e o t h e r w i t h j u s t t h e c e n t e r screw. Thenyoucan r e s t i t on a f l a t s u r f a c e t o a l i g n i t b e f o r e you i n s t a l l t h e o t h e r two screws. You can c u t t h e notch i n t h e f r o n t angle w i t h a hack saw, then s h e a r away t h e m a t e r i a l between t h e c u t s w i t h a cold c h i s e l while holding t h e angle i n t h e bench v i s e .

BOTTOM VIM

A l l frame members shown a r e 118" X 1 114" a n g l e i r o n . The l o c a t i o n s f o r t h e screws a r e approximate, and a l l o f t h e screws a r e I/&"-20 X 112" cap screws w i t h l o c k washers. Add one o r more f l a t washers i f t h e screws o r o t r u d e .

118" X 1 114" ANGLE

The frame members a r e c u t a t 4 5 d e g r e e s , b u t t h e f i t a t t h e c o r n e r s i s n o t c r i t i c a l e x c e p t f o r appearance. I t would be b e s t t o b o l t t h e t o p p l a t e s , b u t t h e frame members c a n a s w e l l be welded t o g e t h e r . When t h e t o p p l a t e s a r e i n s t a l l e d , you can clamp t h e i column b a s e c a s t i n g i n p l a c e and d r i l l t h e 114" t a p h o l e s b through t h e b a s e c a s t i n g . Tap t h e h o l e s i n t h e t o p p l a t e , e n l a r g e t h e h o l e s i n t h e c a s t i n g t o 5/16", and d r i v e t h e c a s t i n g o n t o t h e column b e f o r e you b o l t i t i n p l a c e . Because t h e column b a s e c a s t i n g was bored p e r p e n d i c u l a r t o t h e bottom s u r f a c e , t h e column w i l l b e p e r p e n d i c u l a r t o t h e mounting b a s e t o p s u r f a c e . From t h i s p o i n t b o t h t h e column and t h e b a s e t o p s u r f a c e w i l l be r e f e r e n c e p o i n t s f o r checking t h e a c c u r a c y a s components a r e added.

!.

41

THE HEAD CLAHP AND WORK TABLE CLAMP ASSEMBLIES

I t would be g r e a t i f we could c a s t a one p i e c e head, w h i c h i s q u i t e a chore i n i t s e l f . .Then a l l we would need i s about $50,000.00 Worth of equipment t o machine it and t h e job would be done. Since $200.00 w i l l buy a p r e t t y g o o d d r i l l p r e s s , and most of us d o n ' t have $50,000.00 t o spend, w e ' l l j u s t f o r g e t about t h a t i d e a and say no more about i t . There i s a cheaper way. The clamps c a n ' t be made with a c i r c u l a r bore because t h e column i s n o t o f u n i f o r m diameter over i t s f u l l l e n g t h . The V block clamps make it p o s s i b l e t o u s e a l e s s t h a n p e r f e c t column because they make c o n t a c t on two p a i r s of opposing p o i n t s . The dimensions given a r e f o r t h e 1 518" d i a m e t e r o f a 1 114" p i p e column. I f you u s e a l a r g e r column you must widen t h e base of t h e V, s o clamping p r e s s u r e w i l l be on o p p o s i t e s i d e s t o avoid d i s t o r t i n g t h e column. The head clamp and t h e t a b l e clamp d i f f e r o n l y i n t h e length. A l l t h r e e clamp blocks a r e i d e n t i c a l , s o only t h r e e simple p a t t e r n s a r e r e q u i r e d . Only a minimum of d r a f t i s r e q u i r e d on a l l t h r e e p a t t e r n s . Wipe a very small f i l l e t on a l l i n s i d e c o r n e r s . Use 314" t h i c k p i n e s t o c k , and j o i n t h e p a r t s with g l u e and b r a d s . Form t h e V ' s c a r e f u l l y t o reduce f i n i s h i n g work on t h e c a s t i n g s .

-rm 7

HEAD CLAMP U K E 1BASE

@ GATE

DRAFT

The a n g u l a r b l o c k s a r e a l l i d e n t i c a l , and i t r e q u i r e s twelve of them t o make t h e t h r e e p a t t e r n s .

GATE

TABLE CLAMP B A S E , MAKE 1

CLAMP BLOCK, K 4 K E 3 Make j u s t one of each p a t t e r n , b u t t h r e e c a s t i n g s a r e made w i t h t h e clamp b l o c k p a t t e r n . A l l r e q u i r e a 1 114" s p r u e o n e i t h e r s i d e a s i n d i c a t e d , and a 1 1 / 4 " r i s e r connected t o t h e o p p o s i t e s i d e w i l l be needed t o avoid a s h r i n k c a v i t y . You could a l s o s e t t h e r i s e r i n t h e c e n t e r of t h e p a t t e r n , a s i n d i c a t e d on t h e clamp b l o c k p a t t e r n drawing. A s always, c l e a n up t h e c a v i t i e s i n t h e mold c a r e f u l l y b e f o r e c l o s i n g up t o pour.

MACHINING THE CLAMP BASES The drawing on page 4 3 shows a t o p view of t h e assemb l e d clamps. Two 318"-16 X 3 112" c a p screws a r e used w i t h each clamp block. Note t h e p o s i t i o n i n g of t h e b l o c k s on t h e s i d e view. D r i l l 5/16" h o l e s t h r o u g h t h e b l o c k s on 2 114" c e n t e r s , and clamp t h e b l o c k and b a s e t o g e t h e r w i t h a l e n g t h of p i p e between them t o g u i d e t h e d r i l l a s y o u d r i l l t h e t a p h o l e s i n t h e b a s e . E n l a r g e t h e h o l e s i n t h e b l o c k s t o 3/8", and t a p t h e h o l e s i n t h e b a s e s 318"-16. Make s u r e t h e V b l o c k s c o n t a c t t h e column e v e n l y , and c o r r e c t t o a good f i t by f i l i n g i f neccessary. By b o l t i n g t h e clamp b a s e s t o t h e f a c e p l a t e w i t h a s h o r t l e n g t h of p i p e t h e same d i a m e t e r as t h e column for a s p a c e r and f a c i n g it o f f , t h e machined s u r f a c e w i l l be p a r a l l e l t o t h e column. See t h e p h o t o s o f t h e t a b l e clamp base on pages 23 and 2 4 . The head clamp base r e q u i r e s o n l y f a c i n g o f f , w h i l e t h e t a b l e clamp b a s e n e e d s t o b e d r i l l e d and tapped. You can u s e d i a g o n a l l y o p p o s i t e h o l e s i n t h e head clamp b a s e f o r mounting, b u t i t w i l l p r o b a b l y be b e s t t o d r i l l and t a p two h o l e s n e a r t h e c e n t e r j u s t f o r mounting on t h e f a c e plate. This casting i s j u s t barely wlthin t h e capacity of t h e home made l a t h e , s o i t must be c a r e f u l l y c e n t e r e d on t h e f a c e p l a t e . U s e c a p s c r e w s and f l a t washers through t h e s l o t t e d h o l e s i n t h e f a c e p l a t e f o r mounting, andadjust s o t h a t the f l a t surface i s o a r a l l e l t o the face p l a t e . Tighten t h e b o l t s j u s t enough f o r a f i r m h o l d , b u t d o n ' t o v e r - t i g h t e n and d i s t o r t t h e f a c e p l a t e o r t h e p i p e . Rot a t e Che work by hand, t o be s u r e of c l e a r a n c e , and f i l e t h e c o r n e r s o f t h e c a s t i n g i f i t w o n ' t c l e a r when c e n t e r e d . Mark t h e c e n t e r of t h e t a b l e clamp b a s e and punch i t . Mount it on t h e f a c e p l a t e w i t h t h e l e n g t h o f p i p e , and b r i n g up t h e t a i l c e n t e r c o e n t e r t h e punch mark a s you c e n t e r i t o n t h e f a c e p l a t e . C e n t e r it c a r e f u l l y and adj u s t it p a r a l l e l t o t h e f a c e p l a t e b e f o r e f a c i n g i t o f f . Face i t o f f c l e a n , a n d c u t a s m a l l dimple i n t h e cent e r f o r t h e d r i l l t o s t a r t . Use t h e t a i l s t o c k chuck t o d r i l l a 5/16" h o l e t h r o u g h t h e c e n t e r , a n d g u i d e a 318"-16 tap w i t h t h e t a i l c e n t e r t o t a p t h e h o l e . Turn t h e f a c e p l a t e by hand a s you t a p t h e h o l e . Face o f f a d e p r e s s i o n about ,020" deep t o a d i a m e t e r of about 2 1/2" s o t h a t o n l y t h e o u t e r d i a m e t e r o f t h e t a b l e arm w i l l c o n t a c t i t . The remainder o f t h e work t a b l e w i l l come a b i t l a t e r . 45

THE HEAD CHANNEL CASTINGS This i s a s i m p l e p a t t e r n w i t h even 112" s e c t i o n t h i c k n e s s throughout. There a r e two i d e n t i c a l channels, s o only one p a t t e r n i s r e q u i r e d . Only aminimum of d r a f t i s needed, and a v e r y small f i l l e t on t h e i n s i d e c o r n e r s . A rout i n e mold, fed w i t h a 1 114" s p r u e a t e i t h e r end.

HACHINING THE HEAD CHANNEL CASTINGS The head clamp base i s i n s t a l l e d on t h e column, and i t s s u r f a c e h a s been machined p a r a l l e l t o t h e column. The head channels w i l l be machined with t h e i r f r o n t and back s u r f a c e s p a r a l l e l t o provide a t r u e v e r t i c a l s u r f a c e f o r t h e q u i l l g u i d e when they a r e b o l t e d t o t h e head clamp. The beginning procedure i s t h e same a s f o r machining t h e accessory a n g l e p l a t e s . A p a i r of 5/16"-18 h o l e s a r e tapped i n one l e g of each channel, t h e c o r n e r s a r e f i l e d s o i t w i l l r e s t on t h e f a c e p l a t e without rocking, and one c h a n n e l i s b o l t e d t o t h e f a c e p l a t e with shims t o b r i n g i t t o r i g h t a n g l e s t o t h e f a c e p l a t e . S e e t h e p h o t o on page 15. Then, u s i n g an a c c u r a t e 314" wide guage, such a s t h e blade of a small s q u a r e o r a r u l e , t h e seconrl channel i s b o l t e d t o t h e f a c e p l a t e and shimmed p a r a l l e l t o t h e f i r s t . The exposed l e g s a r e f a c e d off smooth, then t h e channels are i n v e r t e d and b o l t e d t o t h e f a c e p l a t e without shims t o f a c e o f f t h e second s i d e . The r e s u l t i s a p a i r of channels

that just have when

are exactly parallel. T h i s i s a n o t h e r job t h a t i s b a r e l y w i t h i n t h e c a p a c i t y of t h e l a t h e , s o you may t o f i l e t h e c o r n e r s a b i t i f t h e y d o n ' t c l e a r t h e bed c e n t e r e d on t h e f a c e p l a t e .

3 / 4 " GUAGE 'FACE

FACE PLATE

PLATE

Take p l e n t y of time t o s e t up a c c u r a t e l y , and make a s e r i e s o f p a s s e s t o c l e a n up t h e s u r f a c e . Only a l i g h t c u t can be made because t h e work i s s o f a r from t h e support of t h e s p i n d l e bearings. The p h o t o o n p a g e 4 8 shows t h e f i r s t s i d e being f a c e d o f f . Note t h e shims t h a t were c u t from an aluminum beverage c a n . I t r e q u i r e s two b o l t s i n each l e g f o r t h e f i r s t s e t up because t h e mounting s u r f a c e i s rough. Only one h o l e i s t a p p e d i n t h e c e n t e r of each o f t h e f a c e d o f f l e g s f o r t h e second s e t up, b e c a u s e t h e machined s u r f a c e w i l l r e s t and g r i p w e l l on t h e f a c e p l a t e w i t h o u t t h e shims. 47

The t h r e e h o l e s t h a t a r e t a 7 p e d i n e a c h c h a n n e l were Thev w i l l h a v e n o f o r m o u n t i n g on t h e f a c e p l a t e o n l y . The l c ? t h a t h a s j u s t further use i n the construction. o n e h o l e w i l l be b o l t e d t o t h e head c l a n p b a s e w i t h two new h o l e s , t o h e d r i l l e d t h r o u g h t h e clamp b a s e i n t o t h e channel. I n s t a l l t h e head c l a ~ pa t t h e l o w e r end o f t h e column and u s e an a c c u r a t e s q u a r e t o s c r i b e a v e r t i c a l l i n e t h a t i s e x a c t l v p e r p e n d i c u l a r t o t h e mountinp, b a s e t o p s u r f a c e . Then r e n o v e t h e b a s e Cram t h e c o l u n n and s c r i b e a l i n e on e a c h s i d e o f t h e c e n t e r , 318" away and p a r a l l e l . This i s t h e p,uideline f o r locatini: t h e channels. R l i g n t h e chann e l s c a r e f u l l " on t h e s c r i b e d l i n e s , c l a n p t h e n s e c u r e l v , and d r i l l l / / r " h o l e s throup,h h o t h t h e b a s e and t h e chann e l s from t h e r e a r s i d e of t h e b a s e . The h o l e s i n t h e c h a n n e l s w i l l h e e n l a r z e d t o 5/16". and t h e h o l e s i n t h e b a s e a r e t a p p e d 5/16"-18. n o l t t h e c h a n n e l s t o t h e b a s e w i t h 5116"-18 Y 1" c a p s c r e w s w i t h l o c k w a s h e r s , and i n s t a l l t h e clamp a t t h e t o p of t h e c o l u n n . You now h a v e a t r u e v e r t i c a l s u r f a c e on which t o ;nount t h e q u i l l z u i d e .

HEAD CHANNEL

-

These methods and s t a n d a r d s p r o d u c e s o m e t h i n g l e s s t h a n a p e r f e c t assembly, b u t i t w i l l be s o c l o s e a s t o be d i f f i c u l t t o d e t e c t t h e e r r o r i f you have worked c a r e f u l l y . Because che column i s n o t f u l l y machined, i t w o u l d n o t do any good t o c h e c k alignment w i t h a d i a l i n d i c a t o r because no r e l i a b l e r e a d i n g could be had. E i t h e r t h e h e a d o r w o r k t a b l e could a p p e a r p e r f e c t l y a l i g n e d on one p o r t i o n of t h e column, and p o s s i b l y be o u t o f alignment by a h a l f d e g r e e on a n o t h e r p o s i t i o n . More p r a c t i c a l t e s t s can be made a t a l a t e r t i m e , and t h e r e a r e s i m p l e ways t o c o r r e c t e r r o r s .

CHAPTER I V THE QUILL FEED MECHANISM The s p i n d l e is mounted i n t h e q u i l l , which s l i d e s i n i t s c l o s e f i t t i n g guide t o feed t h e d r i l l a c c u r a t e l y and with f i r m support. Since m i l l i n g a r a c k and c r o s s boring f o r a pinion i s out of t h e q u e s t i o n f o r most of u s , we need a device f o r advancing t h e q u i l l t h a t i s within our a b i l i t y . Many have solved t h e problem with a r o l l e r chain and a small sprocket, and t h e i d e a works very well. I t s c o s t i s moderate, and it works n e a r l y as well as a r a c k and pini o n . A b i c y c l e chain w i l l work, but a standard # 3 5 r o l l e r chain is b e t t e r . I ' m s t i l l hung up on t h e i d e a of doing a t e n d o l l a r job f o r f i f t y c e n t s , s o my s o l u t i o n i s a c a b l e winch. I used a 1/16" c a b l e t h a t was intended t o o p e r a t e t h e brakes on a b i c y c l e . I t c o s t $1.00 and I used j u s t h a l f of i t , s o I was a b l e t o s t a y within t h e proposed budget. There i s no doubt t h a t a chain d r i v e i s much s t r o n g e r , and t h a t should be your choice i f you plan on a l a r g e amount of heavy duty work with your d r i l l p r e s s , but t h e c a b l e winch w i l l serve f o r a l l ordinary purposes. A small sprocket would be i n s t a l l e d o n t h e c r o s s s h a f t i n p l a c e of t h e winch drum, and t h e s t u d r e q u i r e s abracke t t o a t t a c h it t o t h e chain. A l l o t h e r d e t a i l s of cons t r u c t i o n remain t h e same. The smooth top i d l e r w i l l work a s well f o r t h e chain as i t does f o r t h e c a b l e . The s e c r e t o f success with t h e c a b l e feed i s t o posit i o n t h e drum s o t h a t t h e c a b l e e n t e r s and leave s t h e h o l e s o t h a t i t does n o t f l e x a t t h e sharp bend. I t w i l l g i v e long s e r v i c e i f p r o p e r l y i n s t a l l e d , but w i l l soon break i f allowed t o f l e x each time t h e q u i l l i s f e d .

RIGHT

50

WRONG

t

THE C H A I N DRIVE QUILL FEED The c r o s s s h a f t i s f i t t e d w i t h a 10 t o o t h 1/35 sprocke t , and t h e i d l e r i s p o s i t i o n e d s o t h a t t h e f r o n t loop of t h e c h a i n t r a v e l s p a r a l l e l t o t h e v e r t i c a l s u r f a c e of t h e head channels. The 318" s t u d i s threaded i n t o a tapped h o l e i n a 2" l e n g t h o f 114" X 314" s t e e l and locked with a jamb n u t . The s t u d b r a c k e t i s f a s t e n e d t o t h e c h a i n w i t h two 3/16" b o l t s through t h e c h a i n and i n t o a tapped 118" X 112" X 1" s t e e l n u t p l a t e . A s h o r t l e n g t h of c a b l e i s f a s t e n e d t o t h e s t u d b r a c k e t , r u n s over t h e i d l e r , and connects t o t h e r e t u r n s p r i n g .

CUTAWAY VIEW WITH RIGHT CHANNEL CLEARED AWAY

THE CABLE WINCH FEED

A s p e c i a l c r o s s s h a f t i s prepared, and t h e s t u d i s a d i f f e r e n t arrangement, but t h e c a b l e d r i v e i s t h e samein a l l other d e t a i l s . I ' v e used t h e c a b l e method some y e a r s ago on a l a r g e f l o o r model d r i l l p r e s s . A t t h e time I used 118" c a b l e , I t would n o t be and i t was q u i t e a chore t o thread i t . p r a c t i c a l t o u s e a 118" c a b l e i n a small machine, but i t w i l l g r e a t l y s t r e n g t h e n t h e feed i f y o u u s e a d o u b l e s t r a n d of 1/16" c a b l e . That would r e q u i r e l a r g e r h o l e s i n t h e drum and s t u d , but a l l o t h e r d e t a i l s would be t h e same a s f o r t h e s i n g l e s t r a n d . I ' v e d r i l l e d numerous h o l e s with my s i n g l e s t r a n d feed, including 518'' h o l e s i n s t e e l , and it appears amply s t r o n g f o r t h e work.

CUTAWAY VIEW WITH RIGHT CHANNEL CLEARED AWAY

The s t u d i s a 318" cap screw with t h e head c u t away, and a 118" h o l e i s d r i l l e d through 318" from t h e threaded A p a i r of n u t s d r i v e two f l a t washers t o g e t h e r t o end. clamp t h e c a b l e .

The 2 112" l e n g t h i s g r e a t e r than needed. The a c t u a l l e n g t h w i l l be determined when t h e q u i l l i s i n s . t a l l e d . A small f l a t i s ground o r f i l e d on t h e t o p s u r f a c e f o r a s e t screw t o s e a t a g a i n s t . Threading t h e c a b l e i s easy i f done i n sequence, but i t r e q u i r e s a b i t o f study. A s i n g l e s t r a n d i s i l l u s t r a t ed, b u t t h e procedure i s t h e same with a double s t r a n d .

HOLE I N STUD

,

I f you c a n ' t f i n d a s ' n a l l s l e e v e t o make t h e s p r i n g l o o p , y o u c a n d r i l l a 118" h o l e i n a s h o r t p i e c e of s t e e l r o d . Make t h e l o o p a s s ' n a l l a s p o s s i b l e , and n a s h t h e s l e eve f l a t w i t h a ham-er. l i o o k t h e l o o p t o t h e r e t u r n s p r i n g and p a s s t h e c a b l e over t h e i d l e r . S l i p t h e f r e e end t h r o u g h t h e h o l e i n t h e s t u d and t h e n through t h e h o l e i n t h e druT. R o t a t e t h e drum s o t h a t t h e c a b l e e n t e r s a t t h e b o t t o 1 and l e a v e s a t t h e t o p , and clamp t h e c r o s s s h a f t s o i t c a n ' t change p o s i t i o n . Draw t h e c a b l e snur: s o t h a t t h e r e t u r n s p r i n g s t r e t c h e s n o more t h a n llir", and l o c k t h e s e t screw i n t h e drum. P a s s t h e f r e e end of t h e c a b l e o v e r t h e f r o n t of t h e drum, u n d e r i t and up t h e r e a r s i d e , t h e n o v e r t h e t o p of t h e i d l e r and t h r o u g h t h e h o l e i n t h e s t u d . Draw t h e c a h l e snug t o e l i m i n a t e a l l s l a c k , t h e n r a i s e t h e s t u d assembly t o t h e t o n and t i g h t e n i t up t o l o c k t h e c a b l e . The s t u d s h o u l d be locked as h i g h a s p o s s i b l e . The a d j u s t - n e n t s c r e w s on t h e c r o s s s h a f t b e a r i n g s w i l l remove any s l i g h t amount of s l a c k t o e l i l n i n a t e hack l a s h .

You'll n o t i c e i n t h e photo t h a t I f a i l e d t o r o t a t e t h e d r u m s o t h a t t h e c a b l e entered a t t h e bottom. This caused t h e c a b l e t o f l e x a t t h e sharpbend each time t h e q u i l l was advanced, and it wasn't long before i t began t o f r a y . I d i d t h e job r i g h t t h e second time, and i t has endured hundreds of q u i l l advances with no s i g n of f a i l u r e . With t h e s e p r i n c i p l e s understoodyoucanchoose e i t h e r chain o r c a b l e feed, and proceed t o make t h e p a r t s .

THE CROSS SHAFT BEARING SUPPORT CASTINGS One o f t h e most d i f f i c u l t jobs i n machining a o n e piece head would be boring f o r t h e c r o s s s h a f t bearings. By c a s t i n g them s e p a r a t e l y and machining them on t h e f a c e p l a t e , t h e job becomes simple. These c a s t i n g s w i l l be t h e same whether y o u u s e c h a i n or cable feed. An opposing p a i r i s needed, but both c a s t i n g s a r e made f r o m o n e t h r e e p i e c e s p l i t p a t t e r n . The main body can be a b i t t r i c k y i f you a r e n o t experienced i n l a y o u t , so f o l low t h e simple s t e p s and i t w i l l be a breeze. Prepare a block of pine 3/8"X2 1/4"X31/4", and draw a l i n e o n t h e c e n t e r . Then draw two crossed l i n e s a s shown o n t h e s k e t c h . The crossed l i n e s a r e t h e c e n t e r s f o r t h e circular portions.

i

1I

'

1 2 Useacompass o r a c i r c l e template t o draw c i r c l e s on the c e n t e r s made by t h e crossed l i n e s . Only one of t h e s e i s r e q u i r e d , and i t w i l l be formed without any d r a f t because i t i s r e v e r s i b l e . This i s a good e x e r c i s e i n p a t t e r n making, molding and casting, and i t ' s easy and fun t o machine. I t w i l l be a r e a l " show off " p a r t of your machine.

When t h e c i r c l e s a r e drawn, d r a w a d i a g o n a l l i n e t a n g e n t t o them, and another l i n e p a r a l l e l t o t h e t a n g e n t and 112" i n t o t h e l a r g e c i r c l e .

5

6

Connect t h e p a r a l l e l l i n e s a t r i g h t a n g l e s 318" from t h e l a r g e c i r c l e . Then draw a l i n e t a n g e n t t o t h e small c i r c l e and p a r a l l e l t o t h e c e n t e r l i n e . F i n a l l y , draw a l i n e t a n g e n t t o both c i r c l e s t o complete t h e o u t l i n e . Cut i t o u t t o t h e l i n e with a coping saw o r j i g saw, and sand t h e edges smooth. There i s no d r a f t , s o t h e edges must be e x a c t l y p e r p e n d i c u l a r and very smooth.

The hub i s a s i m p l e d i s c of p i n e w i t h minimum d r a f t . I t i s a l i g n e d w i t h t h e main body by a s m a l l p i n i n t h e exa c t c e n t e r . A small hole i s d r i l l e d i n t h e top t o a c c e p t a g u i d e p i n i n t h e end of t h e s p r u e p i n .

The l u g f o r t h e a d j u s t m e n t screw i s a s i m p l e block w i t h minimum d r a f t , and it i s a l i g n e d w i t h t h e main body by two small p i n s .

UP=

PINS

The p i n h o l e s i n t h e main body a r e d r i l l e d through a t exact t i g h t a n g l e s t o t h e s u r f a c e s o t h a t t h e l o o s e p a r t s ; can be s e t on e i t h e r s i d e t o make an opposing p a i r . The pins can be s m a l l n a i l s , and you can u s e a n a i l of t h e s a q e s i z e t o d r i l l t h e h o l e s i n t h e main body. Make t h e p i n s very s h o r t , cement them f i r m l y i n t h e l o o s e p i e c e s , and make them f i t t h e h o l e s i n t h e main body f r e e l y s o t h e y w i l l s e p a r a t e e a s i l y when t h e mold i s opened. P r e p a r e a 1 114" s p r u e p i n w i t h a s m a l l g u i d e p i n i n $ t h e end t o f i t t h e h o l e i n t h e t o p of t h e hub p i e c e . [ The c a s t i n g s w i l l be bored and f i t w i t h b u s h i n e s . and

The hub w i l l f a c e t o t h e o u t s i d e on e i t h e r s i d e , and t h e adjustment screw l u g w i l l f a c e t o t h e i n s i d e .

LEFT

RIGHT

MOLDING THE CROSS SHAFT BEARIGN SUPPORTS Lay t h e m a i n b o d y p a t t e r n o n t h e molding board and s e t t h e a d j u s t i n g screw l u g p a t t e r n i n p l a c e .

Ram up and vent t h e drag, r u b i n a bottom board, and r o l l over. S e t t h e h u b i n p l a c e and s e t t h e sprue p i n i n n place on t h e hub. SPRUE

DRAG SAND

Ramup t h e cope c a r e f u l l y t o avoid s t r i k i n g t h e sprue p i n . F i n i s h t h e sprue opening t o f h e funnel shape a n d p u l l out t h e sprue pin. Rub i n a bottom board and open t h e mold, layingthecopedown on t h e bottom board. Swab, r a p and draw t h e hub p a t t e r n from t h e cope, and l i k e w i s e t h e main body p a t t e r n from t h e drag. You should be a b l e t o grasp one of t h e p i n s on t h e lug p a t t e r n t o draw i t from t h e drag. Clean up c a r e f u l l y , e s p e c i a l l y t h e sprue, and swab any a r e a s t h a t t h r e a t e n t r o u b l e . Close up and pour r a p i d l y . The sprue serves as a r i s e r , o r it might be more properly c a l l e s a l1 sinking head ''. I t s u p p l i e s molten metal t o t h e heavy hub s e c t i o n as it s h r i n k s on s o l i d i f i cation. Repeat t h e mold beginning with t h e lug on t h e o p p o s i t e s i d e of t h e main body f o r t h e o t h e r bearing support.

MACHINING THE CROSS SHAFT BEARING SUPPORTS Sawoff t h e sprue a t t h e shoulder and l o c a t e t h e cent e r of both c i r c u l a r p o r t i o n s . D r i l l a 114" hole i n t h e small end,which i s t h e mounting e a r , and t a p i t 5/16"-18. Make a punch mark i n t h e c e n t e r of t h e hub. Mount t h e c a s t i n g t o t h e f a c e p l a t e with a s e t screw c o l l a r and a c o u p l e of washers as spacers so t h e lug w i l l c l e a r t h e s u r f a c e of t h e f a c e p l a t e . Bring up t h e t a i l c e n t e r t o e n t e r t h e punch mark i n the hub a s you a d j u s t i t t o c e n t e r . I n s t a l l a c o u p l e o f s e t screw c o l l a r s as a s t o p l u g on the f a c e p l a t e t o p r e v e n t t h e c a s t i n g from s l i p p i n g as you d r i l l and bore t h e hub. Faceoff t h e end o f t h e h u b and c u t a small cone c e n t e r t o s t a r t t h e d r i l l , anduse t h e t a i l stock d r i l l t o d r i l l a 318" o r 112" s t a r t i n g hole. Carefully bore t o .62SW f o r a snug push f i t on a 5/8" X 112" bronze bushing. Push t h e bushing i n and r e p e a t t h e procedure f o r t h e opposite support. There i s no r e a l need t o machine t h e o u t s i d e of t h e hub except t o improve i t s appearance i f you wish. D r i l l and t a p a #lo-24 hole i n t h e c e n t e r of t h e adjusting screw lug s o t h a t t h e screw w i l l engage t h e bottom of t h e head channel when t h e l u g i s i n s t a l l e d . A 1110-24 X 1" machine screw with a jamb nut serves as the adjustment screw.

INSTALLING THE CROSS SHAFT BEARINGS A s no S t e p s were taken t o make t h e b e a r i n g s u p p o r t s i d e n t i c a l , one s i d e i s i n s t a l l e d and used a s a guide f o r positioning the opposite side. Locate, punch and d r i l l a 114" h o l e 318" from t h e bottom of t h e head channel and 1" from t h e r e a r l e g , on one s i d e only. Enlarge t h e tapped h o l e i n t h e e a r t o 5/16" by d r i l l i n g o u t t h e t h r e a d s . Don't e n l a r g e t h e o p p o s i t e s i d e a t t h i s time. Tap t h e h o l e i n t h e head channel 5/16"-18, and b o l t t h e b e a r i n g support t o t h e channel with a 5116"-18 x 1 114" cap screw. I n s t a l l a jamb n u t on t h e i n s i d e .

S l i p a s h o r t l e n g t h of 112" s h a f t through t h e bushing and s l i d e t h e o p p o s i t e b e a r i n g support onto t h e s h a f t and a g a i n s t t h e channel. Clamp i t t o t h e channel a s you adj u s t i t s p o s i t i o n , and d r i l l a 114" h o l e i n t h e channel i through t h e tapped h o l e i n t h e e a r .

I

ADJUSTING SCREWS

CUTAWAY VIEW AT FRONT Tap t h e second h o l e i n t h e c h a n n e l a n d e n l a r g e t h e h o l e i n t h e e a r t o 5/16". The 1 114" b o l t s a r e used because theyhave a s h o u l d e r t h a t i s n o t threaded. A standard 1" b o l t w i l l have t h r e a d s a l l t h e way t o t h e head, and would n o t make a good p i v o t f o r t h e bearing supports. C u t a p o r t i o n o f t h e end of t h e b o l t s away so t h e r e w i l l be c l e a r a n c e f o r t h e c a b l e and r e t u r n spring.

THE CROSS SHAFT

If y o u e l e c t t h e c h a i n d r i v e f e e d , t h e c r o s s s h a f t w i l l s i m p l y b e a 6 1/2" l e n g t h o f 1 / Z W cold r o l l e d s t e e l round. The sprocket w i l l be locked t o t h e s h a f t w i t h i t s s e t screw t o r e p l a c e t h e winch drum. A f l a t should be ground o r f i l e d on t h e s h a f t f o r t h e s e t screw t o s e a t a g a i n s t .

A s p e c i a l s h a f t i s machined on t h e l a t h e i f youchoose t h e c a b l e winch f e e d . I t ' s a s i m p l e between c e n t e r s job, and t h e rough s t o c k i s a 6 112" l e n g t h of 1" o r 1 1 1 8 " c o l d r o l l e d s t e e l round.

Turn t h e 112" d i a m e t e r p o r t i o n t o n e a r s i z e and f i n i s h by f i l i n g and p o l i s h i n g w i t h emery. The s h o u l d e r of t h e drum i s an a i d i n i n s t a l l i n g t h e c a b l e , b u t i t h a s no f u n c t i o n i n t h e o p e r a t i o n o f t h e f e e d . I t ' s s i z e can be anv d i a m e t e r t h a t i s l e f t a f t e r c l e a n i n a IID t h e 0 . D . . and about 1/16" wide.

-

1

When t h e s h a f t i s machined t o s i z e and shape, d r i l l a 1/16" h o l e through t h e c e n t e r o f t h e drum, a n d c o u n t e r s i n k it s l i g h t l y on each end t o break t h e sharp edge.

TAP 114"-28 @-DRILL

1/16''

CUTAWAY VIEW OF DRUM D r i l l a 7/32" h o l e a t r i g h t a n g l e s t o meet t h e 1/16" h o l e , but n o t beyond t h e c e n t e r . Tap t h e h o l e f o r a 114"28 s e t screw. ~ e c a u s et h e s e t screw would c u t t h e c a b l e . a 3 / 1 6 " b a l l -~~ b e a r i n g i s d r o p p e d i n t h e h o l e and a s o c k e t head s e t screw d r i v e s the b a l l against the cable t o lock it.

THE IDLER PULLEY This c a n b e t h e same s i z e and shape whether you u s e a c h a i n o r c a b l e feed. I mounted a s h o r t l e n g t h of 1" cold r o l l e d round i n t h e V block a n g l e p l a t e , and bored a 1/2" h o l e about 1" deep. Then I hacksawed t h e bored blank from t h e s t o c k , i n s t a l l e d a 114" s e t screw, and mounted i t on an arbor between c e n t e r s t o m a c h i n e i t t o t h e same s i z e and shape a s t h e drum. The s e t screw i s used only f o r machining, and a 112" X 318" bronze bushing i s i n s t a l l e d i n t h e bore t o complete t h e i d l e r .

fie

SAW OFF

BORE 112" X 1" DEEP

SET SCREW

INSTALLING THE CROSS SHAFT AND IDLER One c r o s s s h a f t b e a r i n g support m u s t b e r e m o v e d t o i n s t a l l the cross shaft. The l o n g e s t end extends t o t h e right. I n s t a l l a s e t screw c o l l a r on t h e l e f t e n d t o p o s i t i o n thedrum midway b e t w e e n t h e c h a n n e l s . A f l a t s h o u l d be f i l e d o r g r o u n d on t h e s h a f t f o r t h e s e t screw t o s e a t a g a i n s t . L i g h t l y l o c k a s e t screw c o l l a r o n t h e r i g h t end t o hold t h e drum i n c e n t e r p o s i t i o n . A 318"-16 ZY 2 112" cap screw forms t h e a x l e f o r t h e i d l e r p u l l e y , and i t ' s locked w i t h a jamb n u t . The r i g h t hand channel w i l l be d r i l l e d 3/8", and t h e l e f t hand w i l l be d r i l l e d 5/16" and tapped 318"-16. The b e s t way i s t o s t e p d r i l l both h o l e s t o 5/16", e n l a r g e t h e h o l e i n t h e r i g h t channel t o 3/8", a n d t a p t h e h o l e i n t h e l e f t chann e l u s i n g t h e r i g h t hand h o l e t o guide t h e t a p . These h o l e c e n t e r s must be c a r e f u l l y l o c a t e d s o t h e c a b l e o r t h e c h a i n w i l l r u n p a r a l l e l t o t h e f r o n t of t h e channel. We can view t h e head a s though t h e l e f t hand channel were r e moved while we d i s c u s s l o c a t i n g t h e h o l e c e n t e r s .

As t h e c e n t e r o f t h e bearing support moves down and t o t h e r e a r when t h e a d j u s t i n g screw i s turned i n , it should be a d j u s t e d t o i t s e s t i m a t e d f i n a l p o s i t i o n now. A gap of about 114" w i l l be c l o s e enough. W i t h t h e d r u m i n p o s i t i o n and t h e a d j u s t i n g screws s e t , measure t h e d i s t a n c e from t h e f r o n t s u r f a c e of t h e chann e l t o t h e f r o n t s u r f a c e of t h e drum. Add one h a l f t h e diameter of t h e i d l e r t o t h e " A " dimension and l o c a t e t h e i d l e r c e n t e r 112" below t h e t o p edge of t h e channel. This w i l l b r i n g t h e f r o n t s u r f a c e of t h e i d l e r t o t h e same d i s t a n c e from t h e f r o n t a s t h e drum. I n t h e c a s e of t h e c a b l e feed i t w i l l be " A " p l u s 7/16", but you w i l l have t o c a l c u l a t e t h e r o o t d i a m e t e r of t h e s p r o c k e t t o f i n d t h e " A " dimensionifyou use the chain feed. A s l i g h t e r r o r w i l l n o t be s e r i o u s , but g e t i t a s c l o s e a s p o s s i b l e . A small a d j u s t a b l e square i s a handy t o o l f o r such a With t h e job because i t works n i c e l y a s a depth guage. v e r t i c a l c e n t e r l i n e s c r i b e d o n t h e t o p of t h e channel, i t i s easy t o u s e t h e s q u a r e t o drop t h e l i n e down t h e outs i d e of t h e channel and then s c r i b e a c r o s s l i n e a t a d e p t h of 112". D r i l l a 1 / 8 " h o l e i n each channel. Then d r i l l a 3 / 1 6 " h o l e through both channels from one s i d e . Follow w i t h a 114" d r i l l , t h e n a 5/16" d r i l l . Enlarge t h e r i g h t hand h o l e t o 318". and t a p t h e l e f t hand h o l e 318"-16. I n s t a l l t h e i d l e r w i t h i t s a x l e and jambnut, and t u r n t h e a d j u s t i n g screws o u t s o t h a t t h e l u g s r e s t on t h e bottom of t h e channel.

THE RETURN SPRING AND BRACKET The s p r i n g b r a c k e t i s made of a 1" l e n g t h of 118" X 1 112" a n g l e i r o n , and i t ' s b o l t e d t o t h e b o t t o m o f t h e h e a d clamp base w i t h a 114"-20 cap screw tapped i n t o t h e base. See t h e drawing on page 52.

I ' d l i k e t o g i v e an exact s p e c i f i c a t i o n f o r t h e spring, but t h i s i s one of t h e hazards of working o u t o f t h e junk box. The one I used i s wound of 1/16" wire, and it measu r e s 7/16" i n diameter and 3" long, including t h e loops. There i s a d i f f e r e n c e i n t e n s i o n i n s p r i n g s of t h e same apparent s i z e , soyou may have t o d o some experimenting t o find the r i g h t tension. S t i f f enoughtoretum t h e q u i l l , but n o t so s t i f f as t o make t h e feed d i f f i c u l t . INSTALL THE CABLE OR THE C H A I N I n s t a l l e i t h e r t h e c a b l e o r chain as discussed e a r l i e r , and a d j u s t t h e c r o s s s h a f t bearing supports t o t a k e up any s l a c k . E i t h e r t h e c a b l e o r chain i s i n s t a l l e d with t h e a d j u s t i n g screws withdrawn s o t h a t a minimum of t r a v e l i s u s e d t o t a k e up s l a c k . Adjust f o r a smooth motion without t e n s i o n between t h e drum and i d l e r .

THE HAND WHEEL SPOKES Wooden macrame beads a r e a v a i l a b l e i n a 1" diameter with a 318" h o l e through t h e c e n t e r , and t h i s makes a p e r f e c t p a t t e r n f o r t h e b a l l end of t h e spokes. Get t h r e e of them s o you cam mold a l l t h r e e s p o k e s i n a s i n g l e f l a s k . Glue a 318'' l e n g t h of 318" dowel i n o n e e n d o f t h e h o l e t o plug i t , and smoothup t h e plugged end with body p u t t y . A 6" l e n g t h of 318'' s t e e l rod i s s l i p p e d i n t o t h e hole t o complete t h e p a t t e r n , and t h e same r o d i s u s e d a s a c o r e when t h e mold i s poured. A sand match o r a p l a s t e r matchwould be u s e d i f t h i s job was t o be done r e p e a t e d l y , but s u c h l a b o r i s n o t j u s t i f i e d f o r a o n e t i m e job. Simple bedding i s t h e r i g h t way. J u s t ram up a blank drag over a smooth molding board and r o l l i t over. Press a l l t h r e e p a t t e r n s i n t o t h e p a r t i n g f a c e of t h e drag t o t h e h a l f way p o i n t . S e t a 1 114" sprue p i n about 1" away from t h e c e n t e r b a l l and ram up t h e cope. Remove t h e sprue p i n , f i n i s h t h e sprue opening t o a funnel shape and open t h e mold. L i f t o u t t h e p a t t e r n s , and run t h e vent wire through t h e mold from t h e i n s i d e of each c a v i t y i n both t h e cope and t h e d r a g . Cut a g a t e from each b a l l c a v i t y i n t h e d r a g t o t h e p r i n t l e f t by t h e sprue p i n , and c l e a n up t h e mold. 67

S l i p t h e beads o f f t h e r o d s , and s e t t h e r o d s i n t h e o r i g i n a l p r i n t t h a t they l e f t i n t h e mold. Close up t h e mold and pour.

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Cut o f f t h e g a t e s , f i l e u p t h e r o u g h a r e a s a t t h e f i n s and t h e g a t e s t u b , and chuck t h e rod i n your e l e c t r i c d r i l l t o p o l i s h up t h e b a l l w i t h emery c l o t h . Cut 318"-16 t h r e a d s f o r about 112" on each spoke.

THE HAND WHEEL HUB A simple p a t t e r n madeoftwo 2 118" d i s c s o f p i n e t h a t a r e glued t o g e t h e r , and a 1 114" X 3 112" s p r u e p i n with a small alignment p i n i n t h e end t o e n t e r a matching h o l e in t h e hub, and t h e s p r u e forms a shank s o i t can be mounted

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Bore i t c a r e f u l l y f o r a good f i t on t h e s r o s s s h a f t , and hack saw i t from t h e shank. I n s t a l l two 114"-28 s e t screws a t 9 0 degree i n t e r v a l s 318'' from e i t h e r end of t h e c a s t i n g , and mount t h e bored c a s t i n g on a 1/2" arbor between c e n t e r s f o r o u t s i d e machining. Reduce t h e o u t s i d e d i a m e t e r t o 2 " o v e r t h e e n t i r e hub, then r e d u c e t h e s e t screw end t o 1 114" f o r a shoulder of 5/8". Machine a 2 5 t o 3 0 degree bevel beginning 318" from t h e o p p o s i t e end. Face o f f both ends t o c l e a n them up. SET SCREgS AT

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I t would be n e a r l y impossible t o d r i l l t h e angular t a p h o l e s f o r t h e spokes f r e e hand, s o a simple j i g i s u s e d t o mount t h e hub on t h e f a c e p l a t e a t t h e proper angle. A power lawn mower a x l e i s a n o l d f r i e n d by now i f you have b u i l t t h e metal l a t h e . I t p r o v i d e s t h e a r b o r f o r t h e j i g , and i t s hex head i s a convenient index t o space t h e t a p h o l e s a t 120 degree i n t e r v a l s . The mounting block i s a simple aluminum c a s t i n g with a 318"-16 h o l e tapped i n t h e base f o r mounting, and anot h e r of t h e same s i z e t a p p e d i n t h e angular s u r f a c e f o r t h e arbor. I machined mine f r o m a s c r a p by mounting i t i n t h e f a c e p l a t e angle clamps t h a t a r e d e s c r i b e d i n b o o k s 3 and 4 , but I t h i n k i t e a s i e r t o make a p a t t e r n of t h e c o r r e c t s i z e and shape and f i n i s h with a f i l e . I f you have t h e f a c e p l a t e angle clamps, use them t o hold t h e b a s e a s you d r i l l t h e t a p h o l e s with t h e t a i l s t o c k d r i l l . They should be perpendicular t o t h e s u r f a c e f o r an a c c u r a t e s e t up.

The a n g u l a r f a c e i s a t t h e same b e v e l a s t h e hub s o it w i l l be s u p p o r t e d a t r i g h t a n g l e s t o t h e t u r n i n g a x i s of the lathe. The lawn mower a x l e h a s a 112" shank about 1 112'' l o n g , and i t s t h r e a d e d p o r t i o n i s 318"-16 about 1 / 2 " l o n g .

With a l i n e s c r i b e d on t h e f i x t u r e t h a t i s p a r a l l e l t o t h e a x i s of t h e a r b o r , i t i s easy t o b o l t t h e f i x t u r e t o t h e f a c e p l a t e and a l i g n i t h o r i z o n t a l l y w i t h a t o o l i n t h e t o o l p o s t a s you c e n t e r t h e beveled a r e a of t h e hub w i t h the t a i l stock center. Lock t h e h u b on t h e a r b o r w i t h e i t h e r of t h e s e t screws i n t h e hub, and s c r i b e a mark t o a l i g n w i t h any p o i n t on t h e h e x h e a d . Cut a s m a l l dimple t o s t a r t t h e d r i l l , and d r i l l a 5/16" h o l e w i t h t h e t a i l s t o c k chuck. Use t h e t a i l s t o c k chuck t o h o l d t h e t a p a s you s t a r t t h e t h r e a d s s o t h e y w i l l be t r u e w i t h t h e a x i s . R o t a t e t h e f a c e p l a t e by hand w h i l e t a p p i n g .

Loosen t h e s e t screw and advance t h e mark two p o i n t s on t h e hex head of t h e a r b o r , and l o c k i t f o r t h e second h o l e . D r i l l and t a p i t and r e p e a t f o r t h e t h i r d h o l e . One o r t h e o t h e r of t h e s e t screws w i l l be i n a c c e s s i b l e f o r a t l e a s t one o f t h e s e t ups, b u t e i t h e r one i s sufficient. Screw t h e spokes i n t o t h e hub, f i l e o r g r i n d f l a t s on t h e c r o s s s h a f t f o r t h e s e t screws t o s e a t a g a i n s t , and i n s t a l l t h e hand wheel.

Prentice

12

Inch Swing Upright Drill.

The e n g r a v i n g i s from HILL & C l a r k e ' s 1885 C a t a l o g . T h i s was a bench model, b u t n o t a t o y . I t weighed 225 pounds, and i t s mounting b a s e was 12" X 2 4 " . 4 $12 morse t a p e r s o c k e t i n t h e s p i n d l e , and a speed r a n g e low enough f o r l a r g e h o l e d r i l l i n g m a d e i t a h e a v y d u t y machine. The p r i c e , i n c l u d i n g an overhead c o u n t e r s h a f t , was $85.00. Note how t h e components were c a s t and machined separ a t e l y , and b o l t e d t o g e t h e r w i t h f l a n g e d j o i n t s . They f a c e d t h e same problem we do w i t h l i m i t e d f a c i l i t i e s . The c h a i n a t t h e t o p of t h e q u i l l r u n s over p u l l e y s , and s u p p o r t s a weight t o c o u n t e r b a l a n c e t h e q u i l l .

CHAPTER V THE QUILL

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I used 5"-4"-3"-2" d i e c a s t stel, cone p u l l e y s w i t h a 518" b o r e , and was a b l e t o f i n d them only i n S e a r s Tool c a t a l o g . Y o u ' l l need two of them, and i f you u s e t h e r e d u c t i o n f o r l a r g e h o l e d r i l l i n g y o u ' l l need a t h i r d pulbored t o f i t your motor s h a f t . l e y w h i c h c a n b e a 4"-3"-2" There a r e two 518" b a l l b e a r i n g s i n t h e q u i l l , and a p a i r o f t h e same s i z e a r e used i n t h e r e d u c t i o n . The d r i I purchased a l l of ven p u l l e y u s e s two 1" b a l l b e a r i n g s . my b e a r i n g s , b u s h i n g s and s e t s c r e w c o l l a r s from t h e W. W . G r a i n g e r Company, who have branches a l l o v e r t h e c o u n t r y . T h i s i s a w h o l e s a l e company, and you must buy through a d e a l e r o r y o u r employer i f you a r e n o t a r e - s e l l e r o r manu f a c t u r e r . G r a i n g e r ' s number f o r t h e 518" b a l l b e a r i n g i s R-10-ZZ-1L006, and i t i n t e r c h a n g e s w i t h a F a f n i r 57KDD. I t i s an e l e c t r i c motor g r a d e b e a r i n g w i t h 518" bore and The 1" b e a r i n g 1.375" O . D . , and i t s t h i c k n e s s i s 5/16". 73

i s a Grainger R-16-ZZ-1L009, and it i n t e r c h a n g e s with a F a f n i r SlOKDD. The bore i s l " , O . D . i s 2", and i t ' s 112" t h i c k . Grainger'snumberZX529 p i l l o w block has a 518" X 7/8" flangedbronzebushingthatserves w e l l f o r t h e t h r u s t bearing, a n d t h e y s t o c k f i n i s h e d bore bronze bushings f o r t h e c r o s s s h a f t b e a r i n g s and t h e i d l e r p u l l e y . Lacking t h r e a d c u t t i n g g e a r on t h e l a t h e , it i s n e a r impossible t o c u t t h r e a d s on t h e s p i n d l e t h a t would be acc u r a t e enough f o r mounting t h e chuck. The e a s i e s t mount would be a chuck with i t s back bored 5/8" and f i t w i t h a s e t screw. You can g e t one from Gilliom Mfg. I n c . , S t . C h a r l e s , Mo. 63301. You w i l l s e e Gilliom adds i n magazines o f f e r i n g metal p a r t s k i t s f o r wood working machinery. I recommend t h e i r k i t s h i g h l y , f o r 1 h a v e b u i l t some of them t o my complete s a t i s f a c t i o n . I p u r c h a s e d t h e chuck formy d r i l l p r e s s from Wholesale Tool Company. I t ' s a l / 2 " key t i g h t e n chuck w i t h i t s b a c k I t comes w i t h a #1 Morse bored f o r a W33 Jacobs t a p e r . t a p e r a d a p t e r shank, s o it can do double duty a s a t a i l s t o c k chuck f o r t h e l a t h e . I f y o u a r e g o i n g t o b e d o i n g metal work you r e a l l y need t o know about t h e WholesaleToolCompany. Send them $1.00 f o r a c a t a l o g and expect t o be p l e a s e d . They have f o u r l a r g e o u t l e t s , s o o r d e r from t h e n e a r e s t one. Wholesale Tool Co. I n c . , 12155 Stephens D r . , Box 68, Warren Mich. 48090. W T TooltNorth, I n c . , 1234 Washington S t . , Box 481 Stoughton, Mass., 02072. W T Tool/South, I n c . , 4200 B a r r i n g e r D r . Box 240965, C h a r l o t t e , N . C . 28210. Wholesale Tool Co. ofOklahoma, I n c . , 7240 E . 46th S t . Box 45952, T u l s a Oklahoma, 74145. A l l branches have a t o l l f r e e o r d e r i n g number, and they a c c e p t bank c r e d i t c a r d s . T h e i r minimum o r d e r amount i s $15.00, and they s e l l t o i n d i v i d u a l s l i k e you and I . A r e a l l y g r e a t s t o c k a t good p r i c e s , and s e r v i c e i s f a s t . These a r e n o t advertisements from any o f t h e c o m p a n i e s mentioned. A l l o t h e r n e e d e d i t e m s should be a v a i l a b l e i n most moderatelywellstockedhardware s t o r e s and f a r m s u p p l y S t o r e s . Check your junkboxand any broken down a p p l i a n c e s you f i n d l a y i n g about. You might f i n d some of what you need a t n o c o s t . A b u r n e d o u t 1 1 2 " e l e c t r i c h a n d d r i l l may have a c h u c k w i t h a t a p e r e d b a c k b o r e i f i t was a r e v e r s i b l e mod-

THE QUILL SUPPORT CASTINGS The lower b e a r i n g support i s i d e n t i c a l t o t h e h a n d w h e e l hub, and you should have i t c a s t a l r e a d y . The upper support i s l o n g e r , a n d i t has a l u g c a s t on t h a t w i l l be d r i l l e d t o r e c e i v e t h e feed s t u d . Three 2" diameter d i s c s of 314" p i n e stockmakeup t h e main body, and t h e tapered l u g i s f a s t e n e d t o t h e s i d e with g l u e a n d b r a d s . The mold i s fed with t h e same s p r u e t h a t was used f o r t h e h a n d wheel hub and t h e upper s u p p o r t . I t w i l l b e b e s t t o make t h e c i r c u l a r p a r t a b i t o v e r s i z e and mount i t b e t w e e n c e n t e r s t o t r u e i t up s o i t w i l l be t r u e round and c o n c e n t r i c w i t h t h e g u i d e p i n h o l e f o r t h e s p r u e . Add t h e t a p e r e d l u g t o t h e f i n i s h e d body and wipe a smooth f i l l e t a t t h e junction.

FILLET

FILLET

Only minimum d r a f t is r e q u i r e d , and n o t e t h a t it i s p a r t e d a t t h e same plane t h a t i s u s e d f o r t h e sprue guide p i n . Otherwise you could n o t draw i t from t h e mold. The mold i s fed w i t h t h e 1 114" sprue which p r o v i d e s t h e shank f o r mounting i t i n t h e V block angle p l a t e .

MACHINING THE BEARING SUPPORTS Both c a s t i n g s a r e bored t o 1" f o r mounting on an a r bor, and they a r e counterbored t o 1.375" t o r e c i e v e t h e

75

b a l l b e a r i n g s . The b o r e s must be c o n c e n t r i c , s o t h e y a r e done i n sequence w i t h o u t changing t h e o r i g i n a l s e t u p . Yark t h e c e n t e r of t h e c a s t i n g and b r i n g up t h e t a i l c e n t e r t o p o s i t i o n it on t h e t u r n i n g a x i s of t h e l a t h e a s you s e t u p f o r b o r i n g . D r i l l a 3 1 8 " o r 112" s t a r t i n p , h o l e w i t h t h e t a i l s t o c k d r i l l t o a d e p t h t h a t r e a c h e s about 112" i n t o t h e shank. T h i s w i l l be about 2" on t h e lower s u p p o r t , and about 2 112" on t h e upper s u p p o r t . 1 114" o f t h e l u g i s c u t away w i t h a hack saw s o t h e d i a m e t e r can be reduced t o e n t e r t h e q u i l l s l e e v e . T h i s i s a nuch e a s i e r job t h a n t o gake a more comples p a t t e r n and mold w i t h a l o o s e p i e c e . Bore a l l t h e way t o t h e b o t t o m t o 1" d i a m e t e r , and u s e a s h o r t l e n g t h of 1" s h a f t a s a guage t o be s u r e i t w i l l f i t on t h e 1" a r b o r . Then c o u n t e r b o r e t o 1.375" t o a d e p t h

!'!r.,50 0 p e r a t i o : t s t a ' r e c r 1 n s i ~ l e r . 3 ?,1 1t m e , an I ,,~.>': -.!list he v e r v p a t i e n t and n e a s u r e w i t h g r e a t c a r e . I r you a r e n e w t o t h i s work, i t r n a y t a k e t h r e e e v e n i n g s o r more t o do t h e job, b u t remember t h a t you a r e g a i n i n g s k i l l t h a t w i l l repay you f o r your p a t i e n c e l a t e r . I t i s n o g r e a t l o s s i f you s p o i l a c a s t i n g and have t o s t a r t o v e r , and you w i l l do b e t t e r on t h e second t r y . Don't g i v e up.

The b e a r i n g s themselves c a s s e r v e a s t h e g a u g e f o r t h e 1.375" c o u n t e r b o r e , b u t be c a r e f u l n o t t o g e t them s t u c k i n t h e b o r e b e f o r e t h e job i s f i n i s h e d . The c a s t i n g i s n o t d e s i g n e d f o r a f o r c e f i t b e a r i n g , b e c a u s e t h e r e i s no way provided t o d r i v e i t o u t of t h e bore f o r r e p l a c e m e n t . I t should s l i d e i n t o t h e b o r e w i t h f i n g e r p r e s s u r e , and s l i d e o u t w i t h no more t h a n v e r y l i g h t t a p s on t h e bearI t would be b e t t e r t o have t h e c o u n t e r b o r e .001" ing. o v e r s i z e t h a n .0005" u n d e r s i z e .

I-

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4 It 7

LUG CUT AWAY

UPPER

LOWER

A 1/4"-28 s e t screw i s i n s t a l l e d i n each c a s t i n g a t a p o i n t about 3/16" from t h e s h o u l d e r o f t h e c o u n t e r b o r e . The o p p o s i t e end of each c a s t i n g w i l l b e r e d u c e d t o f i t t h e i n s i d e of t h e q u i l l , and t h e s e t screw must n o t e n t e r a t t h e a r e a t h a t i s t o be machined. A f t e r t h e b o r i n g i s completed, andyou have t e s t e d t o be s u r e t h a t i t w i l l f i t t h e a r b o r and t h a t t h e b e a r i n g s w i l l f i t p r o p e r l y , c u t t h e shank o f f w i t h a hack saw and mount t h e c a s t i n g s o n a 1" X 8" a r b o r between c e n t e r s f o r t h e o u t s i d e machining o p e r a t i o n s . The a r b o r should have a f l a t f i l e d o r ground f o r t h e s e t screws t o s e a t a g a i n s t . The q u i l l t u b e i s a 5" l e n g t h of 1 114" p i p e , and i t s i n s i d e d i a m e t e r i s a n y t h i n g b u t smooth and t r u e . I t w i l l be machined on a p a i r of c o l l a r s t h a t w i l l swage t h e i n s i d e d i a m e t e r t o a m o r e d e f i n i t e d i m e n s i o n , which was found by e x p e r i m e n t a t i o n b a s e d o n an e s t i m a t e o f t b e average o f measurements. The b e a r i n g s u p p o r t s w i l l be shouldered s o 1.438" w i l l t h a t they c a n b e d r i v e n i n t o t h e q u i l l tube. be t h e d i a m e t e r o f t h e s h o u l d e r , and t h a t w i l l be a t i g h t

f i t when i t i s d r i v e n i n t o t h e t u b e . \ l a c h i n e b o t h s h o u l d e r s , b u t d o n ' t d r i v e them i n t o t h e t u b e u n t i l i t h a s been

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),>to above shows t h e upper s u p p o r c .ilr:l : t 5 s h o u l .. d e r :-iaciiinerl t o s i z e , and t h e end of t h e l u g h a s been rnachined l i g h t l y t o c l e a n i t u p . The lower s u p p o r t i s b e i n g r e d u c e d t o 1 . 8 7 5 " a f t e r machining t h e s h o u l d e r . I

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UPPER

~

LOWER

The upper s u p p o r t i s b o l t e d t o t h e a n c l e p l a t e and a 318" h o l e i s d r i l l e d throuch t h e l u g t o r e c e i v e t h e f e e d s t u d . Align t h e c a s t i n g c a r e f u l l y w i t h t h e turninp, a x i s of t h e l a t h e s o t h a t t h e h o l e i s w e l l c e n t e r e d . A 114"28 s e t screw i s i n s t a l l e d i n t h e t o p of t h e lup, t o l o c k the feed stud.

A 5 114" l e n g t h o f 1 114" black p i p e f u r n i s h e s roup,h s t o c k f o r t h e t u b e . I t s nominal o u t s i d e d i a m e t e r i s n o t e a s y t o measure because i t i s so rough, b u t i t i s 1.660" i f i t were p e r f e c t l y round. There i s ample s t o c k t o f i n i s h smoothly a t 1.625" i f i t i s c a r e f u l l y c e n t e r e d on t h e l a t h e . Cut t h e p i p e w i t h a h a c k saw r a t h e r t h a n p i p e c u t t e r s s o t h a t t h e ends w i l l n o t be r e d u c e d . The i n s i d e d i a m e t e r i s extremely rough, b u t t h e speci a l a r b o r w i l l c l e a n i t up and swage i t t o a more d e f i n i t e size. Standard s t e e l s e t screw c o l l a r s of 1" bore measure 1.500" on t h e o u t s i d e . Lock a p a i r of them on a 1" a r b o r and reduce t h e d i a m e t e r t o 1.438". These w i l l be d r i v e n i n t o each end of t h e t u b e s o i t can be mounted on t h e a r b o r . Remove t h e s e t screw from one o f t h e c o l l a r s and d r i v e

i t i n t o e i t h e r end of t h e tube. Be c a r e f u l n o t todamage t h e tube o r t h e c o l l a r a s you d r i v e it i n about 314". D r i l l a 5/16" h o l e 3 / 4 " from t h e o p p o s i t e end of t h e tube, a n d d r i v e t h e second c o l l a r i n s o t h a t i t s s e t screw a l i g n s with the d r i l l e d hole. P u t t h e assembly on t h e a r b o r and mount i t between t h e lathe centers.

Make l i g h t c u t s along t h e e n t i r e l e n g t h of t h e tube t o c l e a n i t up, then measure each end t o be s u r e you a r e not cutting a taper. Adjust t h e t a i l s t o c k s e t over i f t h e r e i s any n o t i c e a b l e d i f f e r e n c e i n d i a m e t e r a t each end of t h e t u b e . Very c a r e f u l l y reduce t h e diameter of t h e tube, and f a c e o f f both ends t o reduce t h e l e n g t h t o 5". The f i n ished s i z e w i l l be 1.625", a n d i t w i l l be b e s t t o t u r n i t 1.626" and f i n i s h w i t h a f i l e and emery c l o t h t o a smooth s u r f a c e . Chamfer both ends i n s i d e and o u t s i d e . When t h e t u b e i s machined t o s i z e , d r i v e o u t t h e s e t screw c o l l a r s a n d d r i v e t h e f i n i s h e d b e a r i n g support c a s t i n g s i n t o t h e ends of t h e tube. Be very c a r e f u l n o t t o damage e i t h e r t h e c a s t i n g s o r t h e tube a s you d r i v e them in. The ends of t h e t u b e having been faced o f f square, and t h e s h o u l d e r s of t h e s u p p o r t s a l s o , t h e p a r t s w i l l be w e l l a l i g n e d when t h e s h o u l d e r meets t h e e n d o f t h e tube. ASSEMBLE THE QUILL AND SPINDLE A 82x529 p i l l o w block from W. W. Grainger h a s a 518" X 7/8" flanged bronze bushing t h a t w i l l m a k e a g o o d t h r u s t b e a r i n g f o r t h e lower end of t h e q u i l l . Their 718" s e t screw c o l l a r has a1.375" o u t s i d e d i a m e t e r , which makes i t

A p e r f e c t a d a p t e r t o f i t t h e f l a n g e d bushing t o t h e lower s u p p o r t c o u n t e r b o r e . J u s t c u t t h e bushing t o a s h o u l d e r l e n g t h o f 1/2", and push i t i n t o t h e c o l l a r .

Push t h e b a l l b e a r i n g s i n t o t h e s u p p o r t s and s l i p a 16" l e n g t h of 518" c o l d r o l l e d s t e e l s h a f t through both b e a r i n g s . Push t h e t h r u s t b e a r i n g a d a p t e r assembly i n t o t h e lower end a g a i n s t i t s b e a r i n g , a n d l i g h t l y l o c k a s e t screw c o l l a r a t t h e upper end s o t h a t t h e s p i n d l e e x t e n d s 2" beyond t h e f a c e of t h e t h r u s t b e a r i n g . Lightly lock t h e second c o l l a r t o b e a r a g a i n s t t h e t h r u s t b e a r i n g . SET SCREW COLLAR

I

SET SCREW COLLAR

7 5/8" X 16" SHAFT

THRUST BEARING ADAPTER THE QUILL GUIDE CASTINGS Both c a s t i n g s a r e made from t h e same p a t t e r n and t h e e a r s a r e c u t o f f one c a s t i n g t o make t h e cap. T h i s i s a s i m p l e p a t t e r n t o make, b u t t a k e c a r e t o a l i g n t h e s a d d l e s t r u e s q u a r e and p a r a l l e l s o t h e two h a l v e s w i l l mate w e l l when joined t o g e t h e r . Only minimum d r a f t i s needed, b u t t h e s a d d l e s must be t r u l y p e r p e n d i c u l a r t o t h e b a s e o r i t w i l l be d i f f i c l t t o draw from t h e mold. I t ' s a r o u t i n e mold, f e d a t e i t h e r s i d e w i t h a 1 1/4" s p r u e . Use a 1 114" r i s e r a t t h e o p p o s i t e s i d e t o avoid a s h r i n k d e p r e s s i o n i n t h e base.

I

Note t h a t t h e b a s e i s j u s t 518" t h i c k , while t h e sadd l e s a r e 314" t h i c k . This i s another c a s t i n g t h a t i s j u s t b a r e l y wlthin t h e c a p a c i t y of t h e home made l a t h e . MACHINING THE QUILL GUIDE Saw t h e e a r s off one of t h e c a s t i n g s t o form t h e cap. D r i l l t h r e e 114" h o l e s i n t h e b a s e o f e a c h c a s t i n g and t a p them 5116"-18.

BASE

CAP

The cap w i l l be i n v e r t e d t o mate with t h e base, and both t h e broad f l a t s u r f ace and t h e mating surf ace must be faced o f f on both c a s t i n g s . F i l e t h e mating s u r f a c e so it w i l l r e s t on t h e f a c e p l a t e without rocking, and mount t h e base c a s t i n g on t h e f a c e p l a t e with two 5/16" b o l t s through t h e s l o t t e d holes i n t h e f a c e p l a t e . Tighten only enoughforagoodgrip, don't d i s t o r t the p l a t e or casting

byovertighteningthebolts. Face o f f t h e b r o a d f l a t surf a c e t o reduce i t s t h i c k n e s s t o 112".

FACE OFF

FACE PLATE

--

When t h e f l a t s u r f a c e i s faced o f f , i n v e r t t h e c a s t i n g and mount i t with s h o r t e r b o l t s t o f a c e o f f t h e mating surf a c e . Repeat both o p e r a t i o n s t o f i n i s h t h e cap. The c a p i s f a s t e n e d t o t h e base with four 5/16" b o l t s , and t h e h o l e s must be t r u l y perpendicular. This would be very d i f f i c u l t t o d o f r e e hand, s o t h e job should be done on t h e f a c e p l a t e with t h e t a i l stock d r i l l . The c e n t e r tapped hole i n t h e cap w i l l s e r v e t o mount i t on t h e f a c e p l a t e with t h e h o l e c e n t e r s i n l i n e with t h e turning a x i s of t h e l a t h e . Punch each c e n t e r midway i n t h e f o u r corn e r s , and bring up t h e t a i l c e n t e r t o p o s i t i o n them f o r d r i l l i n g . D r i l l a 114" h o l e through each c o r n e r .

FACE PLATE

I t i s l i k e l y t h a t y o u w i l l have t o f i l e t h e c o r n e r s of t h e cap s o t h a t i t w i l l c l e a r t h e bed. Rotatebyhand t o

check f o r clearance before you t u r n on t h e p o w e r t o d r i l l t h e h o l e s . Reposition f o r each hole c a r e f u l l y , a n d d r i l l a l l f o u r 114" h o l e s through t h e c a s t i n g . The d r i l l e d cap now becomes a j i g t o guide t h e hand d r i l l as you d r i l l t h e t a p holes i n t h e base. Assemble t h e cap and base with one 114" b o l t t h r o u g h t h e c e n t e r of t h e base and cap, and clamp t h e assembly i n t h e bench v i s e D r i l l a 114" hole through t o d r i l l t h e f i r s t tap hole. any of t h e c o r n e r s , and d r i l l a l l t h e way through the base casting. Separate t h e p a r t s , t a p t h e hole i n t h e base In5/16"-18, and enlarge t h e hole i n t h e cap t o 5/16". s t a l l a 5/16"-18 X 2 1 / 4 " cap screw with f l a t washer and lock washer t o reassemble t h e p a r t s . Re-clamp it i n t h e v i s e and d r i l l t h e second t a p hole diagonally opposite. I n s t a l l t h e s e c o n d b o l t b e f o r e you d r i l l t h e remaining two tap holes.

Makeupfour s e t s of shims f o r t h e mating s u r f a c e s so they c a n b e i n s t a l l e d before t h e assembly i s bored. Each s e t should include two .005", two .003", two .002" and These w i l l provide means t o a d j u s t t h e f i t t h r e e .001". o f t h e q u i l l . Mark one corner of t h e assembly before you t a k e i t a p a r t t o i n s t a l l t h e shims, and put i t back toget h e r j u s t a s i t was taken a p a r t .

BORING THE QUILL GUIDE This i s another job t h a t i s j u s t b a r e l y within t h e 7" swing c a p a c i t y of t h e home made l a t h e , so s e t up must be done very c a r e f u l l y . A s i n g l e b o l t w i l l mount t h e angle p l a t e near t h e r i m o f t h e f a c e p l a t e , andone b o l t through t h e angle p l a t e and i n t o t h e c e n t e r hole i n t h e base c a s t i n g w i l l nold i t as y o u s e t u p . A second b o l t through a scrap of 114" X 314" s t e e l w i l l clamp t h e e a r s of t h e base t o t h e a n g l e p l a t e when a l l i s well aligned w i t h t h e t u r n i n g a x i s o f t h e l a t h e .

You can enlarge t h e hole i n t h e angle p l a t e t o 5/16" a n d u s e t h e t h r e a d s i n t h e base c e n t e r hole f o r t h e f i r s t b o l t . The 114" X 314" s t e e l clamp can be d r i l l e d 5/16", and t h e threads i n t h e second h o l e i n t h e angle p l a t e be used. The rough bore, a s c a s t , w i l l be a poor r e f e r e n c e f o r t h e s e t u p , somake a t e m p l a t e of s t i f f paper o r s h e e t meta l t o t a p e t o t h e end of t h e assembly. The j o i n t between t h e halves should be on t h e turning a x i s of t h e lathewhen i t i s e i t h e r v e r t i c a l o r h o r i z o n t a l , s o t h e template need onlyhave a s i n g l e l i n e t h a t coincides with t h e j o i n t . The s i d e s o f t h e base should be p a r a l l e l t o t h e t u r n i n g a x i s , and you can check i t with a t r y square off t h e f a c e p l a t e . Give p l e n t y of time and study t o t h i s s e t up, and r o t a t e t h e workbyhand before turning on t h e power. Add counter weight t o t h e f a c e p l a t e f o r balance.

COUNTERWEIGHT FACE

TURNING -AUS

'TEMPLATE LINE ON CENTER

-\ '

FIRST BOLT

SECOND BOLT AND CLAMP

' ANGLE PLATE The assembly i s faced off on t h e exposed s u r f a c e and c a r e f u l l y bored t o 1.625" t o match t h e diameter of t h e q u i l l tube. Since t h e f a c e d o f f base i s mounted a t r i g h t angles t o t h e f a c e p l a t e , i t w i l l be bored p a r a l l e l t o t h e mounting s u r f a c e of t h e base. When i t i s bolted t o t h e head chann e l s i t w i l l be p a r a l l e l t o t h e column. I spent two evenings Be very p a t i e n t with t h i s job. s e t t i n g u p a n d boring because I d i d n ' t want t o g e t n e a r l y f i n i s h e d and then have t o s t a r t over again. Measure twice and c u t once i s a sound r u l e t o work by.

N o t i c e i n t h e photo below t h a t I have made a h e a v l e r 318" b o r i n g b a r , and mounted i t on t h e compound w i t h t h e clamp dog and a c o u p l e of b o l t s . The same s e t up i s s e e n on page 17 w i t h a 114" b o r i n g b a r . E i t h e r w i l l do t h e job, b u t t h e h e a v i e r b a r speeds up t h e work.

-

v

I U S T 4 I , I , I U G THE IJIJILL (:l.ill)iJ

C l a m p t h e h a s e o f t h e q u i l l g u i d e i n t h e v i s e and i n s t a l l t h e assembled q u i l l i n t h e g u i d e . I t i s l i k e l y t h a t you w i l l have t o add o r remove shims t o b r i n g it t o a good f i t , s o keep n o t e s a s you d i s a s s e m b l e and r e a s s e m b l e t h e g u i d e . The t u b e n e e d s t o be w e l l o i l e d , and you want a v e r y c l o s e f i t f o r a l i g n i n g t h e g u i d e w i t h t h e base t o p . ? l o u n t o n e o f t h e s t e p cone p u l l e y s on a 518" a r b o r between c e n t e r s and l i g h t l y f a c e o f f t h e l a r g e e n d s o i t c a n be u s e d t o s u p p o r t t h e s p i n d l e e x a c t l y p e r p e n d i c u l a r t o t h e base top s u r f a c e . The lower end of t h e s p i n d l e i s s l i p p e d i n t o t h e p u l l e y and r e s t e d o n t h e b a s e t o p s u r f a c e a s t h e head assemb l y i s l o w e r e d on t h e column u n t i l i t s lower edge i s 314" above t h e bottom o f t h e q u i l l g u i d e . Lock t h e p u l l e y s e t screw l i g h t l y , and clamp t h e p u l l e y t o t h e base t o p . Do n o t engage t h e q u i l l f e e d s t u d a t t h i s t i m e . 86

I t w i l l be b e s t t o remove t h e hand wheel f o r c l e a r a n c e d u r i n g t h i s phase of c o n s t r u c t i o n . The remainder of t h e q u i l l feed mechanism i s l e f t i n p l a c e , but it d o e s n o t app e a r i n t h e drawing below f o r c l a r i t y . W h e n a l l i s well a l i g n e d , clamp t h e e a r s of t h e q u i l l guide t o t h e head channels, and d r i l l 114" h o l e s i n t h e head channel, u s i n g t h e two tapped h o l e s i n t h e q u i l l supp o r t base t o g u i d e t h e d r i l l . The cap must be removed t o d r i l l t h e h o l e s , and it w i l l be b e s t t o l a y t h e machine on i t s back s o t h e shims won't be dropped and mixed up. Be c a r e f u l t o keep a l l i n o r d e r s o you can reassemble a s i t was taken a p a r t . Tap t h e h o l e s i n t h e head channel 5116"18, and e n l a r g e t h e h o l e s i n t h e support base t o 5/16". I n s t a l l two 5116"-18 X 1" b o l t s with l o c k washers a n d r e assemble t h e cap before you d r i l l t h e upper h o l e s i n t h e e a r s of t h e q u i l l support base.

Check the alignment a s you snug up t h e lower b o l t s , and be s u r e t h e cap and shims a r e p r o p e r l y i n s t a l l e d as they were removed. S t e p d r i l l 114'' h o l e s through t h e e a r s and t h e head channel, t a p t h e h o l e s i n t h e channel and e n l a r g e t h e h o l e s i n t h e e a r s t o 5/16". I n s t a l l t h e remaining two b o l t s i n the ears. The cap must be removed again s o t h a t t h e feed s t u d can e n t e r t h e h o l e i n t h e u p p e r q u i l l b e a r i n g s u p p o r t . Rei n s t a l l t h e c a p b e f o r e you l o c k t h e s e t screw on t h e feed stud. Now you can add o r remove shims i n t h e q u i l l support u n t i l you have asmooth e a s y feed with j u s t a t i n y b i t of p l a y . The q u i l l tube must be w e l l o i l e d , and make n o t e s a s you add and remove shims s o you d o n ' t g e t mixed up. The q u i l l guide w i l l wear t o a b e t t e r f i t a f t e r some u s e , and you can remove a d d i t i o n a l shims t o b r i n g i t t o a more p e r f e c t f i t l a t e r . I t i s p o s s i b l e t h a t t h e r e may have been e r r o r s a s t h e p a r t s were machined, and your alignment may be something l e s s t h a n p e r f e c t . You can i n s t a l l shims between t h e h e a d clamp base and t h e head channels a t e i t h e r t h e t o p o r t h e bottom i f t h e e r r o r seems s i g n i f i c a n t . I t ' s more l i k e l y t h a t a l l w i l l b e a l i g n e d t o w i t h i n a very small f r a c t i o n of one degree, a n d t h a t w i l l meet t h e requirements of most home s h o p o p e r a t i o n s . I t i s bound t o be a g r e a t improvement over f r e e hand d r i l l i n g i n any c a s e , and any p a r t s t h a t may need re-doing w i l l be more e a s i l y done when t h e d r i l l p r e s s i s complete.

CHAPTER V I THE SPINDLE DRIVE

The d r i v e n p u l l e y i s m o u n t e d on i t s own b a l l b e a r i n g s and s u p p o r t e d t o run c o n c e n t r i c w i t h t h e s p i n d l e s o t h a t no b e l t t e n s i o n i s t r a n s f e r r e d t o t h e s p i n d l e . The keyway i n t h e d r i v e n p u l l e y i s f i t w i t h a f l o a t i n g k e y t o d r i v e t h e s p i n d l e by a keyway c u t i n t h e upper end. The keyway c a n b e c u t on t h e m i l l e r , t h e s h a p e r , o r by hand w i t h t h e simple t o o l d e s c r i b e d . CUTTING THE KEYWAY BY HAND T h i s s i m p l e method i s v e r y o l d , and I ' v e used i t w i t h s u c c e s s anumber of t i m e s . I t h a s been d e s c r i b e d i n Popu l a r Mechanics p u b l i c a t i o n s s e v e r a l t i m e s o v e r t h e p a s t 40 o r 50 y e a r s . I t ' s t h e e a s i e s t way t o c u t t h e keyway i n t h e s p i n d l e i f you have n o t b u i l t t h e m i l l e r o f t h e shaper yet. Five hacksaw b l a d e s a r e clamped i n t h e simple wooden f i x t u r e , a n d i t i s used l i k e a p l a n e o r a f i l e t o c u t t h e keyway w h i l e t h e s p i n d l e i s clamped t o t h e bench t o p . E i t h e r 1 8 t o o t h o r 24 t o o t h b l a d e s w i l l d o t h e job, w i t h 1 8 t o o t h b e i n g t h e b e t t e r c h o i c e . Cheap carbon s t e e l b l a d e s w i l l work j u s t f i n e f o r t h i s job. T h i s t o o l w i t h f i v e b l a d e s c u t s a keyway s l i g h t l y l e s s t h a n 3/16" wide, and i t t a k e s o n l y a b i t of hand f i l i n g t o widen i t t o 3/16" f o r a smooth s l i d i n g f i t on t h e key. The f i n i s h e d keyway i s 3/16" wide, 3/32" deep and 5" l o n g . There i s no harm i n going a b i t d e e p e r .

T 71-

TWO 314" X 2" X 12 112" HARDWOOD

iI

MACHINE SCREW

FIVE 112" X 12" 1 8 T . HACKSAW BLADES

7

BENCH TOP Use t h e t o o l as you would a f i l e o r hack saw. L i f t a t i n y b i t on t h e b a c k s t r o k e , and make firm forward s t r o k e s as you hold t h e t o o l l e v e l with t h e bench. A s i n g l e clamp and a s t o p block w i l l prevent movement f o t h e s h a f t . It won't t a k e long and y o u ' l l have a clean keyway. MILLING THE KEYWAY A simple c a s t aluminum holding f i x t u r e and a f l y cutt e r w i l l do t h e job. The holding f i x t u r e w i l l f i n d many a p p l i c a t i o n s on t h e m i l l e r , shaper, d r i l l p r e s s , and a l s o f o r bench work. E i t h e r t h e m i l l e r o r t h e shaper w i l l do t h e job with t h i s f i x t u r e . I t ' s a simple p a t t e r n and a r o u t i n e molding job, and i t ' s mounted on t h e f a c e p l a t e with a length of s h a f t a s a spacer t o f a c e off t h e bottom s u r f a c e . The r e s u l t i s a V b l o c k w i t h c l a m p s t h a t w i l l mount round work p a r a l l e l t o i t s base.

DRAFT -

1 114" SPRUE

The V has a 90 degree included angle. Make t h e ends a s near i d e n t i c a l a s p o s s i b l e , and mount them on t h e base of t h e p a t t e r n t r u e square and p a r a l l e l . Only minimum d r a f t i s needed, and a small f i l l e t a t i n s i d e c o r n e r s . Two 3/8" elongated holes a r e c u t i n t h e base of t h e c a s t i n g f o r mounting on t h e work t a b l e , and two 5/16"-18 h o l e s a r e tapped f o r mounting i t on t h e f a c e p l a t e t o machine t h e s u r f a c e of t h e base.

F i l e t h e V blocks f o r good c o n t a c t on t h e s h a f t , and mount it on t h e f a c e p l a t e with a 6" l e n g t h of 5/8" s h a f t a s a spacer and f a c e o f f t h e base. Align t h e c a s t i n g s o i t i s near p a r a l l e l t o t h e f a c e p l a t e , and be c a r e f u l n o t t o over t i g h t e n t h e b o l t s . Having been faced o f f with t h e s h a f t i n the V block, t h e f i x t u r e w i l l support t h e s h a f t p a r a l l e l t o t h e work t a b l e of t h e m i l l e r o r t h e shaper. The 318" elongated holes c a n b e c u t with a coping saw a f t e r d r i l l i n g a 3/8" h o l e a t each end of t h e s l o t . Four 3/16" X 314" X 1" clamps a r e tightened with 1/4" cap screws t o hold t h e work i n t h e f i x t u r e .

The s p i n d l e i s clamped i n t h e f i x t u r e , and c a r e f u l l y aligned p a r a l l e l t o t h e work t a b l e t r a v e l . The elongated h o l e s i n t h e b a s e o f t h e f i x t u r e allow f o r adjustment, and YOU can u s e t h e edge of t h e f l y c u t t e r t o t e s t oneach end of t h e t r a v e l t o a l i g n t h e work. You can use a small t r y square r e s t i n g on t h e work t a b l e and a g a i n s t the s i d e of t h e s p i n d l e t o guide you as you p o s i t i o n t h e c u t t e r i n t h e c e n t e r of t h e s p i n d l e . I made a simple s t u b holder f o r t h e m i l l e r s 518'' chuck, and f i t t e d i t with a 3/16" f l y c u t t e r t o m i l l t h e keyway. This i s t h e s i m p l e s t form of c u t t e r , and i t s general anatomy i s l i k e t h a t of a b o r i n g t o o l . I t r e q u i r e s back rake, end r e l i e f and s i d e r e l i e f Wet hone t h e edge t o r a z o r sharpness. Such a c u t t e r seems small, but a 3/16" wide c u t i n s t e e l r e q u i r e s c o n s i d e r a b l e power. I ran t h e m i l l a t 270 RPM and made about10 passes, each.010" deep. You w o n ' t g a i n a n y s t r e n g t h i n t h e d r i v e by c u t t i n g deeper than .loo". L u b r i c a t e t h e t o o l with o i l on each pass, and give i t a slow steady feed.

- - :.....--- - ..RAKE

YW' SET SCREW

RELIEF TOP VIEW

SIDE VIEW

A shaper t o o l i s ground t o t h e same form, a n d t h e s e t up p r o c e d u r e i s g e n e r a l l y thesame. D r i l l a shallow 3/16" hole a t t h e end of t h e c u t f o r t o o l c l e a r a n c e i f you use t h e s h a p e r t o c u t t h e k e y w a y . Use t h e shapers lowest speed and feed about .005" on each s t r o k e . The keyway must be on t h e c e n t e r l i n e of t h e s h a f t , and i t must be p a r a l l e l t o t h e c e n t e r l i n e . Take p l e n t y of time t o make a c a r e f u l s e t up.

THE DRIVE KM This type of key i s c a l l e d a " f e a t h e r " key. I t f i t s c l o s e l y i n t h e p u l l e y ' s keyway, a n d i t has a l u g t h a t ent e r s t h e s e t screw hole s o i t won't f a l l o u t .

Yake i t from a 1 112" l e n g t h of 3/16" X 3 1 8 ' ' key s t o c k . Cut i t t o approximate s i z e w i t h a hack saw, and f i n i s h w i t h a f i l e t o f i l l t h e space of both keyways w i t h j u s t enough c l e a r a n c e f o r asmooth s l i d i n g f i t between t h e p u l l e y and t h e s p i n d l e . The s p i n d l e n u s t move t h r o u g h t h e p u l l e y f o r t h e f u l l l e n g t h of q u i l l t r a v e l w i t h o u t b i n d i n g .

.* ',

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L

Br:

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1:EYllrAY

y e

WITH THE ' ; ' 1 : R

FITTING THE CHUCK I f y o u p u r c h a s e a c h u c k with a 518" s t r a i g h t bore, t h e s p i n d l e end need only have a f l a t ground o r f i l e d f o r t h e s e t screw t o s e a t a g a i n s t . I used such achuck from G i l l i o n on a n e a r l i e r d r i l l p r e s s , and it was e n t i r e l y s a t i s factory. The chuck you see i n t h e p h o t o s was purchased from t h e WholesaleToolCo. I t came w i t h a 8 1 morse t a p e r adapter, which adapts i t f o r use i n t h e l a t h e t a i l stock, and i t s I t ' s an easy job t o back i s bored f o r a jacobs t a p e r . c u t t h e jacobs t a p e r on t h e d r i l l p r e s s s p i n d l e . You can mount t h e s p i n d l e i n a p a i r of pillow blocks, d r i v e i t with t h e same p u l l e y arrangement a s f o r d r e s s i n g t h e column, and form t h e t a p e r with a f i l e . You'll n o t i c e an e x t r a bearing support i n t h e photo of my s e t u p f o r t h e column, and t h a t was planned f o r c u t t i n g the t a p e r . The job can a l s o b e d o n e o n t h e d r i l l p r e s s a f t e r t h e motor i s installed. J u s t e s t i m a t e t h e t a p e r a s compared v i s u a l l y with t h e tapered adapter, and f i l e t h e r o t a t i n g s p i n d l e t o a near approximation. S t a i n t h e t r i a l t a p e r with prussian blue o i l p a i n t , hold i t s t a t i o n a r y , and r o t a t e t h e chuck one t u r n by hand t o r u b t h e s t a i n o f f t h e high s p o t s . When you remove t h e chuck you w i l l be a b l e t o see whether t o i n c r e a s e o r r e d u c e t h e t a p e r . When t h e t a p e r i s r i g h t , you w i l l f e e l no s i d e play and y o u ' l l have t o r a p t h e chuck with a hammer t o g e t i t o f f t h e s p i n d l e end. I wanted a more p e r f e c t l y c o n c e n t r i c t a p e r , so I removed t h e s p i n d l e form my l a t h e , i n s t a l l e d a 314" X 518" bushing i n t h e l a r g e end, and i n s t a l l e d t h e d r i l l p r e s s s p i n d l e t o c u t t h e j a c o b s t a p e r with t h e compound. I made t r i a l passes, t e s t i n g as described a b o v e , u n t i l I had t h e conpound angle s e t c o r r e c t l y , andthen f i n i s h e d t h e t a p e r with a few more l i g h t passes.

CAUTION: THIS TYPE OFCHUCK MOUNT I S NOT SUITABLE FOR ANY PURPOSE BLIT DRILLING. SUCH ACCESSORIES AS FLY CUTTERS, ROTARY PLANING HEADS, GRINDING WHEELS, SPIRAL END MILLS OR SUCH TOOLS THAT TEND TO DRAW OUT OF THE CHUCK CAN NOT BE USED SAFELY. A SUDDEN J A R CAN DISLODGETHECHUCKANDSEND I T FLYING ABOUT YOUR SHOP. COMMERCIALLY BUILT MACHINES HAVE A LOCKING CHUCK MOUNT FOR SUCH ACCESSORIES.

THE THRUST COLLARS The upper c o l l a r merely s u p p o r t s t h e w e i g h t of t h e s p i n d l e and t h e chuck, s o i t c a n be used w i t h i t s s i n g l e s e t screw a g a i n s t a s m a l l f l a t ground o r f i l e d o n t h e s p i n dle. The lower c o l l a r opposes t h e f o r c e o f d r i l l i n g , s o t w o a d d i t i o n a l s e t s c r e w s s h o u l d be i n s t a l l e d a t 120 d e ~ , r e e intervals. Form a s h a l l o w d i m p l e i n t h e s p i n d l e by d r i l l i n g w i t h a t a p s i z e d r i l l t h r o u g h t h e s e t screw h o l e s .

120 -

-I

-=~ ~

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THE DRIVEN PULLEY The b e l t d r i v e a p p l i e s considerable p r e s s u r e on t h e p u l l e y s , and t h e d r i v e n p u l l e y i s mounted on a hollow s h a f t t h a t i s s u p p o r t e d i n d e p e n d e n t l y o f t h e s p i n d l e bearings s o t h a t t h e s p i n d l e won't be drawn out of alignment by b e l t tension. The photo on page 73 shows t h e driven p u l l e y mounted o n t h e h e a d , w i t h i t s c a s t aluminum hub and t h e t h r e e c a s t ings t h a t support it i n alignment with t h e s p i n d l e . I used a 5"-4"-3"-2" d i e c a s t p u l l e y purchased from Sears t o o l c a t a l o g . I t s 518" bore has a 3/16" keyway, and i t i s l e f t i n t a c t . The back s i d e o f t h e p u l l e y i s hollow, and t h e r e a r e four reinforcement r i b s which must b e p a r t l y broken away. The p u l l e y i s then mounted on an arbor between c e n t e r s and t h e r e c e s s of t h e f i r s t s t e p i s bored These p u l l e y s t o make i t c o n c e n t r i c with t h e hub bore. a r e of t h i n s e c t i o n , and only enough m a t e r i a l i s removed t o produce a c l e a n s t r a i g h t s i d e d bore. Mine measured 3.800" a t t h e s t a r t , and f i n i s h e d a t 3.815", so t h e wall thickness was only reduced by .0075".

BREAK AWAY FOUR RIBS

THE PULLEY SPINDLE AND HUB The hub i s c a s t on a l e n g t h of 314" black pipe which w i l l become t h e p u l l e y s hollow s p i n d l e . The p a t t e r n i s a 4" d i s c of 314" p i n e , bored t o an easy s l i p f i t on the pipe.

The p r o t e c t i v e coating i s sanded off t h e pipe, i t

i s packed w i t h molding sand and rammed up i n t h e mold as a c o r e . The d i s c i s drawn from t h e mold, but t h e p i p e i s l e f t i n p l a c e t o become a p a r t of t h e c a s t i n g . I t w i l l be b e s t t o mount t h e d i s c on t h e f a c e p l a t e w i t h a couple of s e t screw c o l l a r s a s s p a c e r s , and bore t h e c o r e h o l e a c c u r a t e l y . Thenyoucan f i l l t h e mounting h o l e s w i t h body p u t t y t o f i n i s h t h e p a t t e r n .

BORE TO FIT CORE,THEN FILL HOLES

-

314" PIPE, 3" LONG

\

DRAFT

Pack t h e p i p e c o r e with sand, s e t i t i n i t s bore i n t h e d i s c and ram up t h e d r a g . R o l l over, s e t t h e s p r u e p i n about 1" away a t any p o i n t , a n d ram up t h e cope. Open t h e mold, r a p and draw t h e d i s c , c u t t h e g a t e and c l o s e up t o pour. The p i p e c o r e w i l l be a permanent p a r t of t h e casting.

MACHINING THE HUB SPINDLE Mount t h e c a s t i n g i n t h e V block angle p l a t e by i t s p i p e s p i n d l e , and f a c e o f f t h e b a s e o f t h e hub. D r i l l two 114" h o l e s i n t h e hub and t a p them 5116"-18. Mount i t on t h e f a c e p l a t e w i t h a p a i r of s e t screw c o l l a r s f o r space r s , j u s t a s you d i d f o r boring t h e c o r e h o l e i n t h e p a t tern. Take p l e n t y of t i m e t o c e n t e r t h e p i p e on t h e t u r n i n g a x i s of t h e l a t h e . The p i p e i s only about .050" over 1" diameter, s o t h e r e i s l i t t l e room f o r e r r o r h e r e . Make s u r e t h e p i p e i s running p a r a l l e l t o t h e t u r n i n g a x i s s o i t won't f i n i s h t h i n a t any p l a c e . The exposed f a c e of t h e hub i s faced o f f t o reduce i t s t h i c k n e s s t o 518". and

t h e d i a m e t e r o f t h e p i p e i s c a r e f u l l y reduced t o 1". Cut t h e p i p e o f f a t 2" from t h e s u r f a c e of t h e hub, and f a c e o f f t h e e n d . Reduce t h e d i a m e t e r o f t h e hub t o e x a c t l y t h e same diameter a s t h e bored s t e p of t h e p u l l e y . Measure very c a r e f u l l y s o t h a t you g e t a snug f i t . A l l of t h i s work must be done without changing t h e s e t u p s o t h a t a l l w i l l be c o n c e n t r i c .

FACE PLATE

-

DIAMETER OF PULLEY BACK BORE FACE OFF

F i n i s h t h e s u r f a c e o f t h e p i p e s p i n d l e with a f i l e unt i l t h e 1" bored b a l l b e a r i n g w i l l s l i p o n e a s i l y without perceptible play. G e n t l y l o c k a 1" s e t screw c o l l a r o n t h e s p i n d l e l 314" from t h e hub t o s e r v e a s a guide f o r t h e r e t a i n i n g r i n g groove. R e s t t h e hack saw blade a g a i n s t t h e c o l l a r a s you c u t a shallow groove f o r t h e r e t a i n e r .

1 FACE PLATE

SET SCREW COLLAR SHALLOW RETAINER GROOVE

The depth of t h e r e t a i n e r groove i s only about .050M, and t h e w a l l t h i c k n e s s of t h e pipe won't allow f o r very much more than t h a t . Use t h e r e t a i n e r a s a t e s t gauge as you make l i g h t c u t s with t h e hack saw. You can f a c e o f f t h e end o f t h e s p i n d l e an a d d i t i o n a l amount when t h e groove i s finished. The hub should f i t t h e back bore of t h e p u l l e y without play, and a few l i g h t hammer blows should d r i v e i t a g a i n s t t h e shoulder of t h e bore. Two 88-32 f l a t head machine screws a r e countersunk i n t h e groove of t h e p u l l e y i n t o tapped h o l e s i n t h e h u b t o f a s t e n i t permanently. The s e t screw c o l l a r i s moved a g a i n s t t h e hub t o s e r v e as a spacer.

SET SCREW COLLAR

THE DRIVEN PULLEY BEARING SUPPORT S i m i l a r t o t h e c o l u m n b a s e c a s t i n g . Onlyminimumdraft i s r e q u i r e d on a l l o u t s i d e s u r f a c e s , b u t t h e bore i s steepl y tapered t o l e a v e a c l e a n c o r e i n t h e mold. Mount t h e p a t t e r n on t h e f a c e p l a t e with a couple of c o l l a r s t o bore t h e c o r e h o l e , t h e n f i l l t h e b o l t h o l e s with body p u t t y t o I t ' s a r o u t i n e mold using a 1 114" f i n i s h the pattern. sprue Machining i s j u s t l i k e t h e column base c a s t i n g . I t ' s mounted on t h e f a c e p l a t e t o f a c e o f f t h e base, then i t ' s i n v e r t e d on t h e f a c e p l a t e t o bore it t o 2", leaving t h e

.

GATE

I

DRAFT

7

on to so of

Tap two 5/16" h o l e s i n t h e base and mount t h e c a s t i n g t h e f a c e p l a t e t o f a c e o f f t h e b a s e and e n l a r g e t h e bore 1 314" f o r a d e p t h of about 1/4". Center t h e c a s t i n g t h e bore w i l l be c o n c e n t r i c w i t h t h e o u t s i d e diameter t h e huh p o r t i o n . FACE PLATE t FACE OFF

+ BORE 1 314"

FACE PLATE FACE OFF

BORE 2"

5/16" BOLTS I n v e r t t h e c a s t i n g on t h e f a c e p l a t e , and again c e n t e r

i t s o t h e b o r e i s c o n c e n t r i c w i t h t h e o u t s i d e diameter of t h e hub p o r t i o n . Face o f f t h e hub and bore it t o 2" f o r a d e p t h of 1 3/16" t o l e a v e a shoulder a t t h e bottom of t h e bore. The b e a r i n g s a r e bored 1" X 2" 0. D . , and they a r e 112" t h i c k . The shoulder a t t h e bottom of t h e bore w i l l r e t a i n them a t t h e lower end, and a p a i r of 114" cap screws w i l l r e t a i n them a t t h e t o p .

I t w i l l be b e s t t o bore t o a s l i p f i t r a t h e r than a force f i t . A spacing r i n g i s m a d e f r o m 1 / 1 6 " X 3/16" s t e e l t o s e p a r a t e t h e bearings. 2'0 D.

One b e a r i n g i s pushed i n t o t h e bore, then t h e spacing r i n g , and t h e second bearing i s pushed i n and f a s t e n e d with t h e two 114" cap screws w i t h f l a t washers and lock washers. Push t h e hollow s p i n d l e of t h e p u l l e y . t h r o u g h t h e b e a r i n g s and i n s t a l l t h e r e t a i n i n g r i n g . Adjust t h e s e t screw c o l l a r t o t a k e u p t h e e n d p l a y and l o c k t h e s e t screw.

I

PULLEY HUB

SPACING R I N G I

THE HEAD SIDE CASTINGS These p r o v i d e mounting f o r t h e p u l l e y bearing support and t h e s w i t c h housing. There i s a r i g h t and l e f t hand member.

518" The dimensions of both p a t t e r n s a r e t h e same. plywood w i l l work OK f o r t h e s e simple p a t t e r n s . Minimum d r a f t i s s u f f i c i e n t , and wipe a small f i l l e t on t h e i n s i d e I t ' s a r o u t i n e mold fed with a 1 114" sprue a t junction. any convenient p o i n t .

MACHINING THE HEAD SIDE CASTINGS Tap a 5/16" h o l e i n t h e c e n t e r of t h e l a r g e s t s u r f a c e of e a c h c a s t i n g . Mount t h e c a s t i n g on t h e f a c e p l a t e with a s t a c k of s e t screw c o l l a r s f o r spacers t o c l e a r t h e l e g , and f a c e o f f t h e s u r f a c e smooth. The faced o f f s u r f a c e i s then mounted on t h e angle p l a t e s o t h a t t h e l e g can be faced o f f a t r i g h t angles t o i t . *FACE PLATE

FACE PLATE

0~1 P+ OFF

ANGLE PLATE

F i n a l l y , r o t a t e t h e c a s t i n g 114 t u r n , and a l i g n t h e faced o f f l e g a t e x a c t r i g h t angles t o t h e f a c e p l a t e t o f a c e o f f t h e t o p s u r f a c e . The bottom s u r f a c e of t h e l e g i s notchedtoclearthemounting e a r s o f t h e q u i l l support, and i t i s l e f t as c a s t .

INSTALLING THE DRIVEN PULLEY Having been machined t r u e square on t h r e e s u r f a c e s , t h e h e a d s i d e c a s t i n g s w i l l support t h e d r i v e n p u l l e y bearing support a t r i g h t angles t o t h e f r o n t v e r t i c a l s u r f a c e of t h e head channels. Refer t o t h e photo on page 7 3 f o r a c l e a r view of t h e i n s t a l l a t i o n . Make a t r i a l assembly by clamping both s i d e c a s t i n g s i n t h e i r approximate l o c a t i o n on t h e head channels with 4" C clamps. I n s t a l l t h e key i n t h e d r i v e n p u l l e y and s l i p t h e e n t i r e p u l l e y assembly and bearing support onto t h e s p i n d l e t o r e s t on t h e s i d e c a s t i n g s . Tap t h e s i d e c a s t i n g s with l i g h t hammer blows as you a d j u s t t h e i r pos i t i o n u n t i l t h e s p i n d l e w i l l move f r e e l y t h r o u g h t h e p u l l e y a s t h e q u i l l i s f e d . Make s u r e t h e r e i s c l e a r a n c e between t h e p u l l e y s p i n d l e and t h e upper s e t s c r e w c o l l a r of t h e q u i l l assembly. Whenall i s well aligned, t h e b e a r i n g support w i l l r e s t squarely on t h e s i d e c a s t i n g s , and t h e s p i n d l e w i l l s l i p through t h e pulley without p e r c e p t i b l e d r a g a s t h e q u i l l i s f e d . Take p l e n t y of time t o do a l l of t h i s work c a r e f u l l y . I f t h e r e has been an e r r o r i n machining any of t h e head p a r t s i t i s l i k e l y t o show up now. You can re-machine the d e f e c t i v e p a r t , o r y o u c a n i n s t a l l shimstocompensate. An e r r o r of 1 degree o r l e s s i s n o t l i k e l y t o be apparent. The s i d e c a s t i n g s a r e each held t o t h e channels with two 114"-20 X 1" cap screws with lock washers. As i n a l l such assemblies, d r i l l t h e tap h o l e through both members, t a p t h e h o l e i n t h e channel, and e n l a r g e t h e h o l e i n t h e s i d e c a s t i n g t o 1 1 4 " . I n s t a l l one b o l t completely before you d r i l l t h e second h o l e , and i n s t a l l t h e second b o l t bef o r e you d r i l l t h e t h i r d hole. C a r e f u l l y check alignment b e f o r e d r i l l i n g each hole. Measure t h e d i s t a n c e between t h e c a s t i n g s both top and bottom t o make s u r e they a r e p a r a l l e l before you i n s t a l l t h e t h i r d and f o u r t h b o l t s . You'll have t o u s e a 6" long b i t t o d r i l l t h e 3/16" t a p h o l e s because of i n t e r f e r e n c e from t h e q u i l l and t h e pulley. When t h e s i d e channels arepermanently b o l t e d i n p l a c e a 114"-20 X 1" cap screw with lock washer i s i n s t a l l e d i n each corner o f t h e d r i v e n p u l l e y bearing support t o f a s t e n it t o the side castings.

FRONT VIEW WITH QUILL REMOVED

The view above i s a s though a l l were c l e a r e d away s o y o u c a n s e e t h e r e l a t i v e p o s i t i o n o f t h e s i d e castings, the p u l l e y b e a r i n g s u p p o r t c a s t i n g and t h e q u i l l g u i d e . I t may be n e c c e s s a r y t o remove t h e p u l l e y t o i n s t a l l t h e b o l t s through t h e bearing support i n t o t h e s i d e c a s t i n g s , b u t I was j u s t b a r e l y a b l e t o i n s t a l l mine w i t h t h e pulley i n place. I f you must remove t h e p u l l e y , be s u r e

t h e b e a r i n g s u p p o r t c a s t i n g i s w e l l clamped t o t h e s i d e c a s t i n g s i n p r o p e r alignment b e f o r e you remove i t . Check alignment by i n s t a l l i n g t h e p u l l e y b e f o r e you d r i l l t h e second b o l t h o l e .

THE SWITCH HOUSING A s i m p l e box w i t h s l o p i n g s i d e s , and i t h a s e a r s t o b o l t t o t h e f r o n t s u r f a c e o f t h e s i d e c a s t i n g s . The opening i s t h e r i g h t s i z e f o r a standard wall switch. A l l f o u r s i d e s s l o p e from t h e b a s e t o t h e s m a l l e r d i mension, and it i s of 114" s e c t i o n t h i c k n e s s t h r o u g b o u t , s o i t h a s d r a f t both i n s i d e and o u t . You could make i t of 114" plywood, b u t p i n e s t o c k i s e a s i e r t o work. Fasten t h e p a r t s t o g e t h e r w i t h g l u e and b r a d s , and sand t h e t o p and bottom s u r f a c e s t o b r i n g them f l a t and even. F i l l any f l a w s w i t h body p u t t y and sand smooth a l l o v e r b o t h i n s i d e and o u t .

SIDES, MAKE 2

EARS, MAKE 2

ENDS, MAKE 2

LUGS, MAKE 2

Cut out a l l of t h e p a r t s t o t h e s i z e and shape i n t h e s k e t c h e s . Fasten t h e e n d s t o t h e s i d e s with g l u e and small brads, leaving an equal amount o f t h e s i d e s t o p r o t r u d e a t both t h e top and bottom. Use coarse sand paper over a blockofwood t o s a n d t h e top and bottom s u r f a c e s f l a t and p a r a l l e l . Cut t h e e n d s o f t h e l u g s t o t h e proper angle t o f i t t h e m t o t h e i n s i d e o f t h e box s o t h e y w i l l be even with t h e top s u r f a c e , and i n s t a l l them with glue and brads. Form t h e proper angle on t h e edges of t h e e a r s and f a s t e n them t o t h e s i d e s t o complete t h e p a t t e r n . Wipe a small f i l l e t a t a l l i n s i d e corners, f i l l a n y f l a w s , andmake s u r e t h e lugs and e a r s have a s l i g h t amount of d r a f t . F i n a l l y , make s u r e t h e p a t t e r n w i l l r e s t squarely on t h e molding board and s e a l with varnish o r lacquer. This must be a double r o l l mold s o t h a t t h e l a r g e green sand core w i l l r e s t on t h e p a r t i n g f a c e of t h e drag r a t h e r thanhang suspended from t h e cope sand. C u t a 2 118" X 4" p l a t e from t h i n s h e e t metal t o c o v e r t h e top opening. Lay t h e p a t t e r n on t h e molding board and s e t t h e cover on i t . S e t a 1 114'' sprue p i n about 1 112" away from e i t h e r end of t h e p a t t e r n and ram up t h e cope. Vent t h e cope with t h e wire, f i n i s h t h e sprue opening and p u l l o u t t h e sprue p i n . Rub i n a bottom board and r o l l over t h e cope. R a m up t h e drag, being s u r e t o f i l l t h e hollow p o r t i o n of t h e p a t t e r n , but d o n ' t ram i t any harder than t h e main body. Vent t h e drag generously, e s p e c i a l l y through t h e core a r e a , r u b i n a bottom board and r o l l over t h e e n t i r e mold. Open t h e mold c a r e f u l l y , and s e t t h e cope on edge behind t h e drag. I t i s most l i k e l y t h a t t h e p a t t e r n w i l l r e m a i n o n t h e drag, i n which case simply rap i t a b i t and l i f t i t from t h e green sand core. I f it remains i n t h e cope, l a y t h e cope down on a bottom board t o swab, r a p and draw i t . Cut t h e g a t e i n t h e cope r a t h e r than i n t h e drag. Be s u r e t o remove t h e s h e e t metal cover, c l e a n u p t h e mold, and c l o s e up t o pour. The housing i s fastened t o t h e f r o n t s u r f a c e of t h e head s i d e c a s t i n g s with four 114" screws o r b o l t s tapped into the side castings. Break t h e p l a s t e r e a r s from a standard 20 amp wall switch, and t a p two #6-32 holes i n t h e l u g s t o mount t h e switch. A stamped s t e e l switch p l a t e w i l l f i n i s h t h e job.

CH.4PTm V I I

THE. .YOTOR DRIVE

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4 t 7. i i n vou c a n a . i,t,,r : r i - s w i t h a 4"-3"-2" p u l l e y on t h e lotor and v o u will have a machine t h a t i s a d e q u a t e f o r many home shop p u r p o s e s . I t w i l l be much b e t t e r i f you add t h e second s t a g e speed r e d u c t i o n , f o r i t i s a l n o s t c e r t a i n t h a t you w i l l want t o do some work t h a t r e q u i r e s t h e lower speed r a n g e . The s i n g l e s t a g e r e d u c t i o n g i v e s a low speed of 690 RPM, and t h a t i s adequate f o r d r i l l i n g a 3 / 8 " h o l e i n s t e e l . The second s t a g e w i l l r e d u c e t h e l o w speed t o a b o u t 2 7 5 R P M s o t h a t you can d r i l l up t o 314" h o l e s i n s t e e l w i t h o u t burning up t h e b i t . I n e i t h e r c a s e t h e motor mounting b r a c k e t and a l l o t h e r p a r t s of t h e motor d r i v e w i l l be t h e same.

THE MOTOR MOUNTING BRACKET A r e c t a n g l e o f 1 1 4 " plywood w i t h a 3 / 4 " X 1" X 6" pine block glued and bradded t o one end forms t h e p a t t e r n .

Only minimum d r a f t i s n e e d e d a t t h e o u t s i d e edges, but t h e elongated h o l e s need more d r a f t . They a r e 5/16" wide a t t h e p a r t i n g l i n e and 7/16" wide a t t h e top s u r f a c e . I t i s d i f f i c u l t t o form such tapered h o l e s , e s p e c i a l l y i n a m a t e r i a l l i k e f i r plywood. You can make a t a p e r e d wooden form, c u t t h e elongated h o l e over s i z e , and mold it t o shape with body p u t t y . M a e t h e f o r m very smoothand c o a t i t with p a r a f i n s o t h e p u t t y won't bond t o i t . J u s t one form w i l l s e r v e t o shape a l l t h e h o l e s , as t h e body p u t t y s e t s up i n j u s t a few minutes.

-4 DRAFT

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1

3bf8 \ /

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O.IFq MOLD WITH BODY PUTTY

The h o l e s must be f i n i s h e d smooth s o t h a t the small c o r e s won't be broken away when t h e p a t t e r n i s drawn. Molding t h e b r a c k e t i s r o u t i n e , but make s u r e t h a t you p r e s s t h e elongated holes f u l l of sand t o l e a v e f i r m cores i n t h e mold. You can p r e s s a couple of small brads i n t o each c o r e b e f o r e you ram up t h e cope t o r e i n f o r c e them. INSTALL THE MOUNTING BRACKET F i l e t h e elongated holes t o a smooth f i t on the 5/16" c a r r i a g e b o l t s t h a t w i l l mount t h e motor. Fasten a 3 112" b u t t hinge t o t h e r a i l with 114" Cap screws with lock washers.

HINGE

->

The o t h e r h a l f of t h e hinge i s fastened t o the l e f t s i d e o f t h e head clamp blocks w i t h t w o 1 / 4 " c a p s c r e w s with lock washers.

MOTOR BRACKET

THE BELT TENSION LEVER

A s i n g l e motion of t h e l e v e r moves t h e motor forward t o r e l e a s e t h e b e l t t e n s i o n f o r f a s t speed changes. Ret u r n t h e l e v e r and t h e b e l t i s t i g h t e n e d . The mechanism must p i v o t o n b o t h v e r t i c a l andhorizont a l p l a n e s , s o t h e l e v e r and linkaremountedonuniversal brackets. The b r a c k e t p a r t s a r e made of s c r a p s of 118" X 1 114" angle i r o n , and t h e l e v e r and l i n k a r e 118" X 1" s t r a p . The p i v o t s a r e 1/4" i r o n r i v e t s , and t h e l e v e r s t o p i s a 114" f i l l i s t e r head screw with a lock washer. Make a l l of t h e p a r t s a s d e t a i l e d . Only one of each i s r e q u i r e d .

FRONT BRACKET

LINK

FRONT BASE

WASHW

Assemble t h e f r o n t bracket t o t h e f r o n t base with a 114" r i v e t . J o i n t h e l i n k t o t h e f r o n t bracket with a 114" r i v e t and a small f l a t washer between t h e j o i n t . A standard 3/16" washer can be reamed t o a c l o s e f i t . There i s no washer i n t h e bracket t o base j o i n t . The elongated h o l e i n t h e base i s e a s i l y formed by d r i l l i n g a 5/16" h o l e and c u t t i n g away the waste with a hack saw. P e e n t h e r i v e t s well t o make a t i g h t j o i n t . Don't o i l t h e i o i n t s a t t h i s time.

a REAR BASE

REAR BRACKET

LEVER

Join the rear bracket t o the rear base with a 114" r i v e t . Join the l e v e r t o the rear bracket with a 114" r i v e t a n d a small f l a t washer between the j o i n t . I n s t a l l a 114" f i l l i s t e r head screw i n the tapped h o l e , whichwill be the l e v e r s t o u .

J o i n t h e l i n k t o t h e l e v e r with a 114" r i v e t with a washer i n t h e j o i n t and t h e assembly i s complete. Wash i t with s o l v e n t and g i v e i t a c o a t o r twoof aluminum p a i n t f o r good appearance. When t h e p a i n t i s dry, p u t a drop of o i l oneach j o i n t and work them around t o f r e e them up. D r i l l t w o l / 4 " holes throughthemotor mounting bracke t t o match t h e h o l e s i n t h e r e a r base bracket. Countersink them f r o m t h e r e a r and i n s t a l l t h e r e a r base with f l a t head screws, n u t s and lock washers.

The f r o n t base bracket i s fastened t o t h e head clamp base with a 5/16" cap screw, f l a t washer and lock washer. P o s i t i o n t h e base on t h e head clamp s o t h a t t h e p i v o t of t h e l i n k and l e v e r i s about 118" above a l i n e through t h e l e v e r p i v o t and t h e f r o n t l i n k p i v o t when t h e l e v e r r e s t s a g a i n s t t h e s t o p . Mark t h e c e n t e r of t h e elongated hole and d r i l l and t a p a 5/16"-18 hole i n t h e head clamp. 118" ABOVE CENTER

5116"-18

X 1" CAP

I

I

The elongated h o l e i n t h e f r o n t base permits a d j u s t m e n t f o r b e l t l e n g t h v a r i a t i o n s . When t h e l e v e r i s r a i s e d t h e motor i s drawn forward t o loosen t h e b e l t f o r speed changes. When t h e l e v e r i s r e t u r n e d t o t h e s t o p t h e motor i s drawn back t o t i g h t e n t h e b e l t . When t h e l e v e r l i n k p i v o t passes over c e n t e r , t h e l i n k a g e i s locked by t h e b e l t tension. THE BELT GUARD There i s p l e n t y of good argument f o r i n s t a l l i n g a f u l l b e l t guard, though I n o t i c e t h a t they a r e o f t e n removed from machines t h a t come equipped w i t h them. I n s t a l l t h e p a r t i a l guard a t t h e f r o n t a t t h e very l e a s t . You may be a b l e toremember t o k e e p your f i n g e r s o u t o f t h e d r i v e , but t h e r e i s a s e r i o u s danger of g e t t i n g your h a i r caught. You a l s o need p r o t e c t i o n i n c a s e a b e l t breaks o r f r a y s . The angle i r o n b r a c k e t s support both t h e b e l t guard and t h e c o u n t e r s h a f t b r a c k e t . They a r e 1/8" X 1 1 / 4 " , and t h e y a r e f a s t e n e d through t h e s l o t t e d h o l e s by t h e same b o l t s t h a t f a s t e n t h e d r i v e n p u l l e y bearing s u p p o r t . Loc a t e t h e s l o t s s o t h a t t h e f r o n t of t h e a n g l e s a r e i n l i n e w i t h t h e v e r t i c a l s u r f a c e o f t h e switch housing. The r e a r a n g l e b r a c k e t s a r e b o l t e d t o t h e s i d e s of t h e head chann e l s . See t h e photo on page 107.

The 9" long angle b r a c k e t i s f o r t h e f r o n t guard only. I f y o u e l e c t t h e f u l l b e l t g u a r d , make t h e b r a c k e t s 20" long with t h e s l o t s and t h e s i d e b r a c k e t s i n t h e same r e l a t i v e position. Loosen t h e p u l l e y b e a r i n g support b o l t s and s l i p t h e b r a c k e t s i n p l a c e f o r a t r i a l assemble t o l o c a t e t h e r e a r s i d e b r a c k e t s . You may have t o u s e washers between t h e

brackets and t h e channels t o bring them p a r a l l e l . Space t h e brackets 6" a p a r t and p a r a l l e l f r o n t t o back. I painted my angle brackets with aluminum p a i n t , and made t h e g u a r d o f h e a v y embossed aluminum such as i s used f o r t h e s o l i d panels i n aluminum storm doors.

Fold t h e hem t o k i l l t h e sharp edge, and bend up a t t h e dotted l i n e s . Fasten t h e guard t o t h e angle brackets with f o u r 114" b o l t s with lock washers. I f you have e l e c t e d t o i n s t a l l t h e f u l l guard, make a box of t h e same m a t e r i a l with t h e r e a r end open and t h e f r o n t end c u t t o match t h e angle of t h e f r o n t guard.

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m

/ PIVOT HERE

A hole w i l l have t o be c u t i n t h e top of t h e f u l l guard f o r t h e s p i n d l e t o pass through.

THE COUNTERSHAIT The bracket c a s t i n g f o r t h e c o u n t e r s h a f t i s somuchlike t h e p u l l e y bearing support t h a t l i t t l e n e e d b e s a i d about

c a s t i n g i t and machining i t . The p a t t e r n i s simple, and molding i s r o u t i n e . Feed w i t h a 1 114" sprue.

You could bore t h e p a t t e r n f o r a 1" core, but i t i s h a r d l y worth t h e l a b o r f o r a o n e only job. I t i s about a s easy t o d r i l l a s t a r t i n g h o l e t o bore t h e c a s t i n g . Tap 5116"-18 h o l e s i n d i a g o n a l l y o p p o s i t e c o r n e r s of t h e c a s t i n g and b o l t i t t o t h e f a c e p l a t e w i t h s e t screw c o l l a r s f o r spacers. Bore t h e c e n t e r t o 1.125" a l l t h e way through, and counterbore t o 1.375" t o a d e p t h of 718".

7k

FACE PLATE

-

OFF

BORE

SPACERS You can bore about one h a l f thousandth u n d e r s i z e f o r a f o r c e f i t on t h e b e a r i n g s , o r you can r e t a i n them with screws and washers a s on t h e p u l l e y bearings. The b e a r i n g s are 518" bored b a l l bearings j u s t a s t h e q u i l l b e a r i n g s . The 0 . D. i s 1.375", and they a r e 5/16" t h i c k . Make a spacing r i n g from 1/16" X 1/4" s t e e l t o sepa r a t e the bearings. The s p i n d l e i s a 3 112" l e n g t h of 518" cold r o l l e d I s t e e l w l t h hack saw grooves f o r t h e r e t a i n i n g r i n g s . mounted mine i n t h e s p i n d l e chuck of t h e m i l l e r t o c u t t h e

grooves. You can do t h e same job by rnountingalength of s h a f t i n a p a i r of p i l l o w blocks t o c u t t h e grooves, then cut it t o length. The grooves a r e spaced 7/8",and you can u s e a s e t screw c o l l a r t o guide t h e hack saw, j u s t a s you d i d f o r t h e driven p u l l e y s p i n d l e . Grind a f l a t on t h e s h a f t f o r t h e p u l l e y s e t screw t o s e a t a g a i n s t .

SPACING R I N G

SPINDLE

COUNTERSHAFT ASSEMBLY

CUTAWAY VIEW AT FRONT

The e n l a r g e d d r a w i n g o n p a c e 116 s h o w s t h e a s s e ~ b l va s though i t were viewed from t h e f r o n t . Enlarge one of t h e ?lake a c l i p h o l e s i n t h e c o u n t e r s h a f t b r a c k e t t o 5/16". of 118" X 314" s t e e l and b o l t i t t o t h e bottom of t h e brack e t w i t h washers t o space i t f o r a smooth slidinp, f i t on t h e r i g h t hand guard a n g l e . You can u s e one of t h e bearing retaining bolts, o r tap a separate hole i n the bracket. Tap a 5/16" h o l e i n t h e l e f t hand guard a n g l e , a t about 1 1 1 2 " from t h e r e a r . I n s t a l l t h e b r a c k e t t o t h e a n g l e w i t h a 5116"-18 X 1 114" cap screw and f l a t washer. Adj u s t t o a good f i t and l o c k t h e b o l t w i t h a jamb n u t . Now you can i n s t a l l t h e second s t e p p u l l e y and t h e mot o r w i t h i t s p u l l e y . >ly machine used a 23" b e l t and a 27" b e l t , b u t you had b e s t measure t o f i n d your b e l t s i z e .

CHAPTER V I I I THE WORK TABLE

The o r i g i n a l work t a b l e support arm, seen i n t h e photo on page 31, was a s i n g l e c a s t i n g , which was t o be machined between c e n t e r s on t h e l a t h e and bored on t h e m i l l e r . I suddenly r e a l i z e d t h a t many of you may n o t have b u i l t t h e m i l l e r , s o I s e p a r a t e d t h e arm i n t o two c a s t i n g s s o t h a t t h e e n t i r e job can be done on t h e l a t h e .

THE TABLE CASTING I t looks j u s t l i k e a l a t h e f a c e p l a t e , and i t i s maI t w i l l be b e s t t o t u r n chined j u s t l i k e a f a c e p l a t e . t h e p a t t e r n t o s i z e on t h e l a t h e s o you w i l l be s u r e t h e c a s t i n g w i l l be within t h e l a t h e s c a p a c i t y . Make t h e f a c e and r i m of 518" plywood, a n d t h e hub of 2" d i s c s of 314" p i n e . Make a wooden form f o r t h e elongated h o l e s , j u s t a s you did f o r t h e motor mounting brack e t , and mold them with body p u t t y . They a r e 318" wide a t t h e p a r t i n g p l a n e and 112" wide a t t h e top. Assemble t h e p a r t s with g l u e and brads, andmount t h e p a t t e r n on t h e l a t h e f a c e p l a t e t o machine t h e r i m and hub c o n c e n t r i c .

Molding i s r o u t i n e , b u t d o n ' t f o r g e t t o p r e s s sand i n t o t h e elongated h o l e s as you ram up t h e d r a g . I t h e l p s t o push a c o u p l e o f b r a d s i n t o e a c h o f t h e small c o r e s bef o r e you ram up t h e cope. This c a s t i n g r e q u i r e s a heavy r i s e r i n t h e c e n t e r t o feed t h e hub. I t w i l l be e a s i e s t t o s e t a 1 112" sprue a t t h e c e n t e r , which w i l l s e r v e a s t h e pouring g a t e and t h e r i s e r . This i s c a l l e d a " pop " gate.

MACHINING THE WORK TABLE The sprue w i l l be on t h e f a c e of t h e c a s t i n g , and an 1 8 t o o t h h a c k saw blade w i l l make s h o r t workof c u t t i n g i t o f f . Mount t h e c a s t i n g o n t h e l a t h e f a c e p l a t e with f o u r b o l t s through t h e elongated h o l e s , u s i n g s e t screw c o l l a r s f o r spacers s o you can bore through without touching t h e l a t h e f a c e p l a t e . Center i t c a r e f u l l y and bore i t through t o e x a c t l y 1". I n s t a l l a 5/16" o r 318" s e t screw i n t h e hub and mount i t on the 1" mandrel t o f a c e i t o f f and machine t h e r i m . The shank t h a t mounts t h e t a b l e o n t h e a r m i s a 3 314" l e n g t h o f l " cold r o l l e d s t e e l . Youcanmount t h e f i n i s h e d work t a b l e on t h e f a c e p l a t e t o s e r v e as a s e t screw chuck t o h o l e t h e shank as you f a c e o f f t h e ends. Grind a f l a t along t h e l e n g t h of t h e shank f o r t h e s e t screws t o s e a t against.

THE WORK TABLE SUPPORT ARM PATTERN A b i t unusual i n shape, but i t ' s designed e s p e c i a l l y f o r machining on t h e small l a t h e . I t ' s a s p l i t pattern with t h e drag h a l f i n two p i e c e s . D r a f t i s provided by t h e s l o p i n g v e r t i c a l members and t h e added wedges. Note t h a t Make t h e c e n t e r body of 112" pine stock. i t t a p e r s 118" on both s i d e s and t h e ends f o r d r a f t both i n s i d e and o u t s i d e .

Add t h e f r o n t end, which forms t h e e a r s f o r mounting t h e t a b l e shank bracket as shown above, and add a wedge t o t h e back s i d e of each e a r f o r d r a f t a s shown below.

The back end i s a h a l f c i r c l e of 314" pine s t o c k , and t h e drag h a l f i s a h a l f c i r c l e of t h e same r a d i u s . Note t h a t t h e drag h a l f i s tapered f o r d r a f t , while t h e cope h a l f i s n o t . A wedge i s added t o each wing of t h e c i r c u l a r p a r t of t h e cope p a t t e r n f o r d r a f t .

4 k 4''

DRAG HALF

A second h a l f c i r c u l a r p a r t i s added t o t h e f r o n t end t o provide support while machining. I t i s the s e c o n d p a r t of t h e drag h a l f , and i t ' s tapered f o r d r a f t . Both c i r c u l a r p a r t s a r e aligned with t h e cope h a l f by small p i n s .

The p i n s can be made of small brads, and a brad of t h e same s i z e c a n b e u s e d t o d r i l l t h e mating h o l e s i n the cope h a l f o f t h e p a t t e r n . They need extend mo more than 1/8", and they must f i t t h e mating h o l e s f r e e l y s o t h a t t h e d r a g h a l f p a t t e r n s w i l l s e p a r a t e e a s i l y and remain i n t h e drag when t h e mold i s opened. Wipe a small f i l l e t on a l l i n s i d e c o r n e r s , f i l l any flaws, andsand smooth both i n s i d e and o u t s i d e before you s e a l with lacquer o r v a r n i s h . Make s u r e t h e d r a g h a l f s e p arates easily a f t e r sealing. MOLDING THE SORK TABLE SUPPORT ARM This i s another double r o l l mold because we want t h e green sand c o r e t o r e s t on t h e d r a g r a t h e r than hang from t h e cope sand. Lay t h e p a t t e r n o n t h e molding board and s e t a 1 114" sprue p i n about 1 112" away from t h e c i r c u l a r end. Ram up t h e cope, using t h e drag h a l f o f t h e f l a s k s o t h e pegs won't i n t e r f e r e . Be s u r e t o f i l l a l l t h e corners, andram uniformly. Ventgenerouslywiththewire. F i n i s h t h e s p r u e opening t o a funnel shape, and remove t h e sprue p i n . Rub i n a bottom board and r o l l over t h e cope. This i s the first roll. S e t t h e drag h a l f p a t t e r n s i n place and ram up t h e drag. Be s u r e t o p r e s s sand i n t o t h e c o r e a r e a , b u t d o n ' t ram i t any harder than t h e main body of sand. Vent t h e

c o r e a r e a generously with t h e w i r e . R u b i n a b o t t o m b o a r d and r o l l over t h e e n t i r e mold. This i s t h e second r o l l .

Push a 1/L" rod through t h e cope sand and r a p t h e p a t t e r n before you open t h e mold. You can push sand back i n the h o l e l e f t by t h e rod, o r you can l e a v e i t open f o r a vent. L i f t t h e cope s t r a i g h t u p and s e t i t on edge behind t h e drag. Rap t h e p a t t e r n a l l around and l i f t it o f f t h e c o r e . Swab t h e drag p a t t e r n p a r t s and grasp them by t h e i r p i n s t o d r a w them from t h e mold. Clean out t h e sprue and c u t a f u l l s i z e d g a t e i n both t h e cope and t h e drag. Use alighttolookintothecavities, and l i f t out any loose sand w i t h a w e t swab. Cleanup t h e e n t i r e m o l d c a r e f u l l y before c l o s i n g up t o pour.

MACHINING THE WORK TABLE SUPPORT ARM The g a t e w i l l be e a s y t o c u t o f f w i t h a n 1 8 t o o t h hack saw blade. The f i r s t s t e p i s t o p r e p a r e 60 degree c e n t e r s t o mount t h e c a s t i n g between c e n t e r s on t h e l a t h e . The o b j e c t h e r e i s t o l o c a t e t h e c e n t e r of the l a r g e c i r c u l a r p o r t i o n and t r a n s f e r i t t o t h e o p p o s i t e end s o the work w i l l be mounted on i t s t r u e a x i s . Some e r r o r i s cert a i n , f o r we l a c k a machined s u r f a c e as a r e f e r e n c e , and p r e c i s i o n l a y o u t e q u i p m e n t i s n o t l i k e l y t o be a v a i l a b l e . The top s u r f a c e i s t h e b e s t r e f e r e n c e we have, so s c r i b e a l i n e along i t s c e n t e r , p a r a l l e l t o t h e s i d e s .

Drop t h e l i n e on e a c h end a t 90 d e g r e e s t o t h e t o p of t h e c a s t i n g . Measure 1 13/16" from t h e t o p s u r f a c e t o t h e c e n t e r of e a c h end. C e n t e r d r i l l each end and mount t h e c a s t i n g between c e n t e r s t o f a c e off t h e c i r c u l a r end. 4 5/16" c a p screw w i t h n u t s on b o t h f r o n t and back of t h e f a c e p l a t e w i l l s e r v e a s a dog t o d r i v e t h e work. The p l a s t i c e l e c t r i c a l t a p e s e e n i n t h e p h o t o i s t o hold t h e e a r of t h e c a s t i n g a g a i n s t t h e d o e .

-

'.-

t a u. two 5/16" i ~ o l r c e n t e r l i n e and b o l t t h e c a s t i n g t o t h e .

on tile

vertical

f a c e p l a t e t o f a c e o f f t h e o p p o s l t e end. S p a c e t h e h o l e s about 1 114" above and below c e n t e r . When t h e f r o n t end i s f a c e d o f f , s c r i b e l i n e s f r o m t h e c e n t e r a t 4 5 d e g r e e s from t h e t o p s u r f a c e , and t a p two5/16" h o l e s 318" from t h e t o p .

Use t h e s e h o l e s t o b o l t t h e c a s t i n g t o t h e f a c e p l a t e , and add a clamD of 114" X 1" s t e e l a s s e e n i n t h e p h o t o .

f a c e ? l ? t e , l r i l l a 5/16" s t a r t i n g h o l e , and b o r e t o a D o n ' t change t h e s e t up c l o s e f i t on a 318" c a p screw.

u n t i l t h e c i r c u l a r p o r t i o n has beenreduced t o s i z e f o r t h e protractor scale. THE PROTRACTOR SCALE I f you have b u i l t t h e m i l l e r o r t h e s h a p e r t h e s t e e l As r u l e used f o r t h e p r o t r a c t o r g r a d u a t i o n s i s f a m i l i a r . t h e r e a r e 360 d e g r e e s i n a f u l l c i r c l e , we o n l y need apply 360 e q u a l d i v i s i o n s t o t h e c i r c u l a r b a s e o f t h e arm and we have i n c r e m e n t s of one d e g r e e each. A f l e x i b l e 6" s t e e l r u l e h a s d i v i s i o n s o f 1 / 3 2 " , and t h a t ' s a c o n v e n i e n t r e a d A a b l e s c a l e . D i v i d e 360 by 32, and t h e answer i s 11.25. c i r c l e w i t h a c i r c u m f r e n c e of 11 114" w i l l measure 1/32" f o r each one d e g r e e d i v i s i o n . Divide 1 1 . 2 5 by 3.1416 t o f i n d t h e d i a m e t e r , andyou have approximately 3.581. The t h i c k n e s s o f t h e r u l e i s about .020", s o t h e d i a m e t e r i s reduced an a d d i t i o n a l .040" s o t h a t t h e f i n i s h e d s i z e i n c l u d i n g t h e t h i c k n e s s of t h e r u l e i s 3.581". Then e a c h 1/32" d i v i s i o n on t h e r u l e w i l l r e p r e s e n t a o n e d e g r e e d i v i s i o n o n t h e c i r c l e . There a r e o n l y 192 1/32" d i v i s i o n s on t h e 6" r u l e , b u t y o u o n l y n e e d 180, s o i t s e r v e s w e l l f o r t h e need a t hand. S u b t r a c t t w i c e t h e t h i c k n e s s of your r u l e from 3 . 5 8 l W , and t h a t w i l l b e t h e f i n i s h e d s i z e o f t h e c i r c u l a r p a r t o f t h e work t a b l e s u p p o r t arm. The s i z e i s t h e s a q e f o r a r u l e w i t h 1/16" d i v i s i o n s , b u t of c o u r s e t h e d i v i s i o n s w i l l each r e p r e s e n t two d e g r e e s . A 1/8" s c a l e would g i v e f o u r d e g r e e d i v i s i o n s . Fasten t h e r u l e t o t h e t o p h a l f o f t h e c i r c l e w i t h two s m a l l machine screws, and f a s t e n a n a d j u s t a b l e w i t n e s s mark p l a t e t o t h e t o p o f t h e clamp b a s e . The s u p p o r t a r m i s f a s t e n e d t o t h e clamp base w i t h a 318"-16 c a p screw w i t h a f l a t washer.

tate tal. than tion shop

I t ' s a simple matter t o loosen t h e cap screw and rot h e arm through any angle from v e r t i c a l t o horizonThe s c a l e d i v i s i o n s a r e l i k e l y t o b e something l e s s p e r f e c t l y a c c u r a t e , but they w i l l be w i t h i n a f r a c of one degree, and t h a t i s c l o s e enough f o r most home work.

THE TABLE SHANK BRACKET CASTING This i s t h e f i n a l s t e p i n c o n s t r u c t i o n , and i t ' s an easy c a s t i n g and machining job. The p a t t e r n r e q u i r e s minimum d r a f t , and i t ' s fed with a 1 114" sprue a t e i t h e r s i d e and a 1 114" r i s e r a t t h e o p p o s i t e s i d e .

4

2%"

k

GATE

L MACHINING THE TABLE SHANK BRACKET

D r i l l a 114" h o l e through t h e c e n t e r of t h e c a s t i n g , and t a p 5/16" t h r e a d s from both top and bottom. Bolt t h e c a s t i n g t o t h e f a c e p l a t e . t o f a c e o f f t h e smaller s u r f a c e , then i n v e r t it t o f a c e o f f t h e l a r g e r s u r f a c e . TAP 5116"-18

FACE OFF FIRST

FACE OFF TAP 5116"-18

Clamp t h e shank bracket t o t h e support arm and i n s t a l l a 5/16" cap screw i n t h e c e n t e r o f e a c h e a r . I n s t a l l t h e assembly on t h e column and chuck a c e n t e r d r i l l b i t i n t h e chuck t o d r i l l a c e n t e r i n t h e bracket.

Nount t h e bracket t o t h e f a c e p l a t e with the angle p l a t e and bring up t h e t a i l c e n t e r t o p o s i t i o n i t f o r t h e D r i l l a s t a r t i n g h o l e with the t a i l boring o p e r a t i o n . s t o c k chuck and bore t h e b r a c k e t t o l " f o r a c l o s e f i t on t h e work t a b l e shank. FACE PLATE

BORE TO 1"

ANGLE PLATE

I n s t a l l t h e bored bracket on t h e support arm and ins t a l l t h e work t a b l e shank i n t h e bracket, locking it with a s e t screw i n t h e f r o n t h o l e i n t h e bracket. Congratulations, youhave converted your scrap box t o a p r a c t i c a l d r i l l p r e s s . I t , t o g e t h e r with your l a t h e and t h e m i l l e r o r t h e shaper w i l l make easy work of building t h e a c c e s s o r i e s i n b o o k 116. You have only begun t o enjoy t h e freedom and c r e a t i v e p o t e n t i a l of your o m machine shop. There i s nothing t o s t o p you now.

I N D E X TO MAJOR SUBHEADINGS B E L T GUARD---------------------------------------BELT T E N S I O N LEVER-------------------------------BORING TOOLS-------------------------------------CABLE WINCH FEED---------------------------------CHAIN D R I V E Q U I L L FEED---------------------------CHUCK FITTING------------------------------------COLUMN B A S E CASTING------------------------------COLRJTERSHAfl-------------------------------------CROSS SHAFT--------------------------------------CROSS S H A F T BEARING SUPPORTS---------------------DRAm--------------------------------------------D R E S S I N G T H E COLUMN------------------------------D R I V E KN----------------------------------------D R I V E N PULLEY------------------------------------FILLETS------------------------------------------HAND WHEEL---------------------------------------HEAD CHANNEL CASTINGS----------------------------HEAD CLAMP---------------------------------------HEAD S I D E CASTINGS-------------------------------I D L E R pULLm--------------------------------------

MOLDING------------------------------------------MOTOR MOUNT BRACKET------------------------------MOUNTING BASE------------------------------------P A R T I N G PLANE------------------------------------PATTERN MAKING-----------------------------------P L A I N ANGLE PLATE--------------------------------PROTRACTOR SCALE---------------------------------P U L L m S P I N D L E AND HUB---------------------------Q U I L L BEARINGS-----------------------------------Q U I L L GUIDE--------------------------------------Q U I L L TUBE---------------------------------------RETURN S P R I N G BRACKET----------------------------RISERS-------------------------------------------S P I N D L E KEYWAY-----------------------------------SPRUE--------------------------------------------SWITCH HOUSING-----------------------------------TABLE CASTING------------------------------------TABLE SHANK BRACKET------------------------------THRUST COLLARS-----------------------------------V BLOCK ANGLE PLATE------------------------------WORK TABLE S U P P O R T ARM---------------------------WORK TABLE CLAMP----------------------------------