Vertical Milling in the Home Workshop

ARNe -_3 THROP

VERTI MLLING IN THE ME 0 K OP

l1J.J.J.1.illlillJ 1III111111 ! 11111111111111111111111 I1111I1111111 blllLJ..l.W.J..W..W.WJ..W.LL.Ll.W...I.LW.I..l.W.l..I.J.l.I..l.lJI

CJ)

"

o o

a:J

(J)

C

G)

»

::IJ

Argus Books Argus House Bounda ry W ay Hemel Hempstead Hertfordshire HP 2 7ST Eng la nd

CONTENTS Chapter One

EVOLUTION OF THE VERTICAL MILLER 12 Early history of indu strial m achines: milling in th e early sma ll lath es : mi lling attachmen ts for lat hes ci rca 19 20s: E.T, W estbu ry's experimental machine 1964: the Dar e-Westbury m achine 1968: cu rre ntly avail able sma ll machi nes and attach ments,

Chapt er Tw o

MILLING FLAT SURFACES 27 Surf aces paralle l to table: simple fixed-radius f1 ycutt ers: var iab le-radius bor ing head flyc utting: multiple -tooth face m ills: work hol ding: m ult ip le­ pass mi lling: surfaces square w it h table : using side of end mill.

Chapter Th ree

SLITTING AND CUTTING 35 Use of slitting saw for cutting through machinery component bosses : eccentric sheaves and straps : mar ine type big ends of connecting rods.

Chap te r Four

KEYWAY CUTTING 37 Endm ill ing round ended 'feath er' keyways : keyways on taper shafts : use of disc tvoe cutters for plain sunken keyways : \Noo dru ff keyways: making Woodruff cutters in the home workshop : table of suggested sizes of \N oodruff keys and kevv vavs fo r model engineers,

Chapter Fiv e

FLUTING COMPONENTS OTHER THAN TOOLS 43 Correct form of flutes ir loco connecting and cou pling rod s: mounting rods against anglepla te for flu ti ng : parallel flutes: taper flutes: preferred type of cutting too l.

First pub lished 1977 Second im pression 1979 Sec ond edi ti o n 1984 Rep rin ted 1986, 1988 , 1989, 1990, 1991 . 1993

© A rg u s Bo o ks Ltd

1977

All r ights reserved . No p art of this publication m ay be repro d uced in any f o rm by print. photography, microfilm or any othe r mean s wi thout written permission from th e pub lisher. ­

ISB N 0 852 42 843

x

Ph o t ot y p esetti n g by Perf o rm an ce T y pesetting, Milton Key n es Print ed and bound i n G reat Br it ai n by Biddies Ltd . Guil d f o rd and K in g 's Lynn

Chapte r Six

BORING 45 Dealing with parts too large to swing in lathe: trepanning large ho les.

Chapter Seven

'J I G- BORIN G' 46 Using the miller as a measuring machine : drilling ho les at one setting of work and precise cent res: eng ine be am: b ack-lash pr ecaution s: tri p gea r com ­ pon ent : mu lti-ho le boiler plates.

Chapter Eight

DIVI DING HEADS AND TOO L MAK ING 66 Fluting taps : example 5-flute Acme tap : producing a small fine too th milling cutter w ith ball end : use of table stop blocks: combination of rotary tabl e with ma in table movement: large 60 deg ree coun­ te rsink fluting .

Chapter Thirt een

DIVIDING HEADS AND GRAD UATED SCALES 71 Cutti ng graduation marks : use of rotary 'engr avi ng' cutters : use of no n-r otating plani ng t ype tools : use o f table stops to contro l line lengths : graduating cyli ndr ica l scales: gradua ting flat angular scales : checking correct way of figuring when stamping scales ,

Chapter Fourt een

CUTTER SPE EDS FOR VERTICAL MILLERS 74 Speeds affect ti me occupied on job: speeds too high may cause excessive cutter wear and chatter : rigi di ty of work, cutter and mac hine inferior as a rule to i ndu st rial condi tions, dry cutting inst ead of lubricated : Tabl e III gives speeds for cutters in different kinds of tas ks : m achi ne speeds may no t alwa ys be suitable .

Chapter Fifteen

WORK -HOLDING WITH D IFFICULT SHAPES 78 Comparison with full scale engi neering : use of chucki ng pieces on components : thin components and use of ad hesives : advisability of making fixtures fo r difficul t pieces : three -s ided angleplates.

Chapter Sixteen

CHUCKS FOR MILLING CUTTERS 81 Never use taper shank tools or chucks without drawbar: chucks for screw ed shank self -tightening collets : Clarkson chuck : Dsborn Titanic chuck: Chucks for tee -headed locking cutters: Clare chucks : use of small end mills and D-bits withou t locking features : ph ilosophy of 't hrow - aw ay ' cutters.

PROFILING 49 Curves on parts too large for lathe: loco frames : smokebox castings : machine pad bolts: loco con ­ nec ting rod s and coupling rod s.

Chapter Nin e

END-ROUNDING 52 Use of hardened f ilin g gu ides deprecated: mou nting work on rot ary table: sta nd ard size guide plugs: anti-slip precau tio ns: direction of feed for exte rnal and i nte rnal surfaces.

Chap te r Ten

DIVIDING HEADS 54 Simple ungeared div iding heads : using change w hee ls as index plat es: examples o f d ividing w or k : h exagons. squares. dog clutch teeth : avoiding odd numbers : the Myford w orm -geared dividing head : avoiding back-lash erro rs : packing block for bringing to lathe centre height: universa l steady stand fo r Myfo rd head: three further dividing heads.

Chapter Eleven

Chapt er Tw elve

DIVIDING HEA DS AND GE AR- C UTT IN G 62 Limitations to strai ght spu r gears : sim ple head : M yford worm -geared head: tooth cutting on integral pi nion : use of home made Ilvcut ters: Brown & Sharpe disc type cutters : selectio n of cutter to suit numb er of teet h : cutting a large coa rse tooth gea r: anti-slip back-up de vices ,

List of Illustrations Fig .

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 4 25 26 27 28

Ab w oo d mi llin g attac hme nt of the 19 2 0 s

E. T. W estb ury 's m ill ing m achine Dore-W estbu ry m achine Dare-W estbury M k II machine Rodney attachm ent Rodney m ach in e Am o lco attach men t A mol co m achine M ent or mach in e M aximat attach me n t Astr a m ach ine Tw in machi ne Senior m achin e Set of three fl ycu tt ers Flycu tt ing a bracket Flycutti ng connecting rod ends Flycutti ng t apered bar mat eria l Flycutting cy linde r soleplat e Facem il l M illing flywheel joint face Mi ll ing crosshe ad slide M illing bear ing jaw s in bedpl at e Slitting boss of ca sting Milli ng feath er kevw av M illing feath er keyw ay on tap ered shaft Mil ling keyway wi th slitting saw Se t of four Woodruff keyway cutters M ill ing W oodruff k evwav

13

14

15

16

17

18

19

20

2 1

23

2

22

26

2 8

28

29

29

30

3

31

32

33

35

3 7

38

39

39

4 1

29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58

Fluti ng loc omo tive co nnect ing rod Draw ing of stea m hook (lever) Phot ograph of st eam hook Profilin g pad bo lt Profiling coupling rods End-rounding wi th rotary tabl e Cutti ng t eeth in do g clutch par t Draw ing of st eady stand for Myfo rd div id ing head St eady in use on a gear cutti ng opera tic Thro p divid ing head Th om as versat ile divid ing head Kib bey/M .E.S. dividl nq head Clos e-up of flycut ter and pi nio n Gearcu tt ing w ith Brow n & Sharpe cutter Fly cutt ing 10 d .p, gearwh eel. front view Fly cu tt ing 10 d.p. gearw hee l. rear view Flut ing A cm e thread tap Cutt ing teeth of ba ll-end cu tt er Close- up of ball-end cu tte r Gashin g flutes in large count ersinking tool Rear v iew showing stead y stand in use Cyli nd rical m achine compone nt being grad uated Close -up of prev ious ope rat ion Graduating part -ci rcul ar arcua t e scal e on fl at surfa ce Tape -he ld w orkpiece bein g flyc ut Hern inpwav three-side d anglep late Tw o of the th ree sizes of Herninqwav ang leplates Clare mi ll ing chu ck Clark son mi ll ing chu ck Osborn mill i ng chuc k

4 4

4 7

48

50

50

53

5 5

56

58

5 8

59

60

63

63

64

6 5

66

67

68

69

70

72

72

73

79

79

80

82

82

83

Preface In th e eng ineering in dustry the vert ic al miller is very widel y used . no t o nly for batch product lorrbu t also for tool ma king and the 'one -off' jobs whi ch are so common in general eng inee ring. In the home worksho p. w her e most job s are 'one-o ff' th e ve rsatility of th e machi ne makes it an i m port ant comp anion to the lathe. Thi s book des crib es many of the infinitely wid e range o f op er ation s wh ich can be done. and all those described are illustrated by photographs so that under­ st anding of th e methods is assured . These cove r work on part s of model loco mot ives. stationary engines machi nery . cutting too ls. gea rs, clutches, etc. Full informat ion is given o n the machine accessories wh ich are requi red, suc h as var ious types of cu tters and t he chuck s needed for t heir mounting on the m achi ne spind le. The use of chea p hom e- m ad e cutt ers i s shown and encouraged. Guidance is also give n on th e work- holding dev ices such as clamps. packings, vices. angle plates, dividing heads. rot ary table s, and w hich of thes e are needed for part icular kinds of w ork .

CHAPT ER 1

[},'\

Evolution of the Vertical Miller Th e horizontal mi lli ng machine evo lved natura lly fr om the lathe in t he fi rst or seco nd decade of t he nine tee nt h century. Eli W hitney (U.S.A.) is said t o have had one in use about 18 18 . and in Tools for the Job the lat e LTC . Rolt reco unt ed how the yo ung engineer J ames Nasm yth {later to become famous as the inventor of the stea m ham mer and ot her app liances l fixed one up and m illed the fla ts on hundreds of tiny hexagon nuts for a model of a Mauds lay marine eng ine. w hile working fo r Henry Ma uds lay . Draw ings of the ear ly hori zont al mill ers show suc h a resemb lance to t he la th es of that period that almost certai nly they were in fact lat hes w hich had been adapt ed to mil ling. The cutters we re really files. made by the fi le m akers of the tim es, using t he 'hand­ cu tt ing ' methods (really a hamm er and a spec ia l chisel) w hic h we re the only practice available at that tim e. The evolution o f the ve rti ca l m iller came nat ural ly afte r t he ho rizo nt al m achi ne. I have not found any reliable refe rence to a date by w hic h the vert ical m iller h ad appeared in industry , thoug h this m ust have been we ll before 190 0 . W he n model eng ineering sta rted to beco m e an esta bl ished hobby at the t urn of th e century quite a variety o f sma ll 12

lath es we re provided by di fferent makers. and the great ver satili ty of th e lathe created in it self a te ndency to make the lathe do every opera tion that arose . This wa s enhan ced by th e fact th at ma ny modellers were working men with very litt le cash to spend o n their hobby. Many we re the inge nious attachment s devised to enable the lat he to carry out work it had never been intended to do . Such makers as Drum m ond Brothe rs modified their lathes wit h tee-slott ed boring tables to help in this work . and even bro ught out t he famous ro und - bed lat he. wh ic h although int ended for a cut -price market. also had bu ilt into it the abi lity to do a lot more than just simple turning . But as the years wen t by it became ever more appa rent somet hing better was needed f or mi lling operations . No ne of the small mille rs produced by the mac hine tool industry we re oriented towards the home w orkshop, T hen in the 1920s the Abwcod Tool and Engi neeri ng Co. produced an exce l­ lent vertical mi lling at tachmen t fo r mounting on smal l lathes. especia lly the in. flat bed Drum m ond . though popula r adjustable features made it applicable to othe r lat hes too . It had a No. 1 Morse tape r arbor which fitted in to the lathe

3t

j:ig . t Abv/ood milling attachment of the 19205

13

spindl e. and bevel gear s with keywa yed shafts took the drive up to the vert ica l cutt er spind le. w hic h had a No. 1 M orse inte rna l taper. A ll the gears w ere equa l rat io m it re beve ls. so the cutter ro t at ed at t he sam e speed as th e lat he spi ndle . and all t he six speeds of the lathe were usable. The w or k wa s mounte d on the lathe bo ring table. and po wer feeding in one direction ca me from the lathe screwcut­ t ing gear. A phot ograph of this uni t set up on a Myford Super 7 is show n in Fig. 1. It wa s unfort una tely a low -vol um e. labou r int ensive uni t w it h vee slides needing hand scrapi ng . but w as selling in 19 30 for 7 guin eas. about a quar ter of the cost of

the Dru mmo nd lat he. A lt ho ugh o ut of producti on for ma ny year s now . it was in its time a co urage ous effo rt . but be lo nge d to the age w hen most home lathes were driven by fla t belt fro m a tread le or cou n­ tars haft. and the cost of electric mot ors made th e in d ep enden t m o to r drive uneconom ic in ho m e hobb y appli cati ons. Bu t th e need for a handy vertica l m illi ng ma chine had been recogn ised. and in the ear ly 19 6 0s that very good friend of model engineers. Edgar T. W est bury . com plete d an ex pe r im en ta l m ac hi ne. wh ich he desc ribed w it h drawings and pho t og rap h s in t he Model Eng ineer during 19 6 4 . T hat too wa s a very labou r

ig, 3 D ore- W est bury machine

Fig. 2 E.T. Westbury 's milling machine

14

inte nsive machine w ith vee slides, and the main castings w ere m uch t oo big to b e machi ned in th e ave rage ho me workshop. A t that ti m e he w as una ble to find any engi neering fir m wi lli ng to take it over and manu facture it. or ev en to do th e machin­ ing on a contract basis at such a price as it was thought m odel engi neers would be wl llinq to p ay. T hree years later I found myself with the opportunity to tak e a fresh loo k at th is desig n, whi ch he had di scussed w ith me during the experim ent al pe riod . I evolved a new set of d rawi ngs for a sim ilar machi ne, but using flat slideways more economically constructed. a reducti on gear f or low er bottom speeds , hollow spindl e for a draw bar. and othe r changes

int ended to make econom ies or im prove the pe rformance . This new design was discussed w ith Edgar. w ho agreed to the use of the name 'Dore-Wes tburv ' , the machi ne to be sold as a kit of sem i­ fi nished compone nts by my existing fir m Dore Engi nee ring, I was abl e to pla ce th e m achi ning o f the compo nen ts w ith a number of firms al read y kno w n to me . and the fi rst sets of mat erials began to go ou t to custo mers early in 1968. Si nce that t im e m any hundreds o f sets have bee n distributed . all over the wo rld . and are still be ing made in ever grea te r quant iti es by M o d e l En g i n e e r i n g S er v i c e s . o f Chest erfield . w ho too k it over from me in 19 7 1, w he n I wa nted , on acco unt o f age , to red uce m y comm it men ts , Castin gs to the origi na l design are, howeve r, st ill available fro m Waking Pre­ c is io n M od els o f 16 Dovecot Park . A berdour. Fife. Scotland KY3 OTA . and a machine fro m these is sho w n in Fig. 2. The Da re-W estbu ry mac hi ne is depicted in Fig. 3 and the sim ila rity be twee n the m wi ll be at onc e appa ren t. Du ring it s entire life the Dar e-Westbury has been un dergoi ng sma ll im provement s. and th e present supplie rs have now dec ided that t h e m o d i f i c a t i o n s a re s u ff ic ie n t ly st abilised for the presen t ve rsion t o be titled the M ark II model. From now on all ma chines supplied w ill be of this form . though st ill subject to certain op tional vari ations which custome rs w ill be able to select as t hey wi sh. T he more importan t chang es incl ude an in crease in t he quill travel from 2i in. to 4-1- in . Ext ra pull ey ste ps with a new ty pe of be lt extend the speed rang e sligh tly fro m 32 to 1880 r.p.m. w ith more int er­ m ediat es. provid ing for boring head fl y­ cutting on large radii right th ro ugh t o keyw ay cu tt ing with 1/ 16 in. cutters. The reduction gear system now fi tt ed has helical gears w hich run in an oil-bath.

15

Fig. 6 Rodne y ma chine

sealed against leakage even w hen incli ned away from the vertical, and is Quieter th an former ly. A large r table , 20 in. by 6 in., can be had as an optiona l al terna tive to the in. The co lum n and norm al 16 in. by cros s tube are steel. as always, but now t in. thick and eno rmously st iff. in. diamete r m icro m et er d ials are now

5t

standa rd. Th e down-feed w orm has for conveni ence been transferred to the right hand side of the head, a coa rser pitch rack is now used . and ther e are a numbe r of oth er m ino r im provements.

2t

18

Opposite, Fig. 7 Amolco atta chm ent 19

Although co lleg es and commercial workshops wil l probably wish to use the all -over be lt guard, it may be d eba ta ble if th e co st of this is justified fo r the so lit ary mat ure m ode l le r alo ne i n hi s home workshop. An alternative belt gua rd wh ich covers t he spi nd le pulley only and do es not im pede belt chang ing so mu ch is ava ilable and is shown on the M ark II machine in Fig. 4 .

No do ubt the most importan t i m pro ve­ ment is the (optional) provision of po w er feed fo r the lo ng movement of the table. A small m ot o r wit h a 4-step pul ley and enc lose d w o rm reduction gear provides feed rates of .5 . .62 . .85 and 1.1 inches pe r mi nute. A num ber of attachm ents similar in general concept , though much different in de ta il. to t he old Abwood . have com e on