watchmaking excerp

7/29/2019 Watchmaking Excerp

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Gog D 1981

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ackwdgmt vPc t th Thd edt xPc xTh Cu Pt facing xv

1. WorKsHoP anD eQUiPMenT 1Wkhp spcfct 1Dwg Mthd 4Vu ad 6Th lth 6

lth Typ 7st 17B 18Bdg W 19shc 19Mug T d Gug 20Ptg d Bg Mch 22optc Mug 25

2 HanD Tools 27G Bch T 27

D d Dg 34scw d Thdg 40shud scw 47

3 FinisHinG sTeel anD Brass 51Hdg st 51Fhg Mt 54Phg 60

4 TUrninG 69T Mk Bc st 69Tug d Fttg P 86

5 WHeels anD Pinions 101Wh-Tth Fm 101P Cutt 111Wh Cutt 112T Dg 113Dpthg 121Wh Cuttg 123Tppg T 131P Cuttg 134Hdg d Phg 139

ecp Wh 140

6 MaKinG sMall CoMPonenTs 147squ H 147B ab 148rtcht Wh 150Pw 151stp Wk 151B d Cv 153Bc r 154

lv d Pt Fm 160Chmt Dtt 164Hd 168

7 JeWellinG 175stdd-szd Jw 175Cuttg d shpg st 177T Mk Jw H 180T Ft th Jw 183Th ruby Cyd 184T shp Pt d lckg st 188

ConTenTs


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8 esCaPeMenTs 195G Pcp 195Vg ecpmt 197Cyd ecpmt 199Dupx ecpmt 203lv ecpmt 206T st out egh ecpmtwth rtcht Wh f 15 Tth 221T st out sm-equdttCub-tthd cpmt wthWh f 15 Tth 222Chmt 224T st out th Chmtecpmt 233

Th Futh Dvpmtf th ecpmt 233

echppmt ntu 235

Dtchd ecpmtWthut lubct 236

idpdt Dub-Whecpmt 237

Dub rd impuwth sg Wh 239

C-ax ecpmt 242ext Ft C-ax ecpmt 247act f th rvd

C-ax ecpmt 248symmtc C-ax ecpmt 251

9 MainsPrinGs anD aCCessoriesPw Vt 253Mpg Dm 253spg pw avb 254Typ f Mpg 255equzg th Fc f th spg 257Ctt Fc ecpmt 258Mkg th Fu 264Wdg idct 266stp Wk 270

Wdg 272equt f Tm 273

10 MoVeMenT DesiGn 279Htc d G 279Pg th Mvmt 281Dt Dg f TubMvmt 282

Pg th Cg 285Mkg th Fm 286supptg th Cg 294Tub Cg 296Mkg Tub Cg 303

11 THe BalanCe anD sPrinG 319Tmptu Cmpt 319Bc Wh 325

Bc spg 334spg stud d Ct 347T Ft th Bc spg 349

12 CaseMaKinG 355sdg 355Wtch G 369

13 enGine-TUrneD Cases anD Dials 371D Mkg 384D Ft 394

scd Cc d sct idx Pt 395Fhg th D 396Cg d og 402

sct Bbgphy 405

appdx i 407appdx ii 408appdx iii 410

idx 412

vi Contents


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Plate 0

Action of Chronograph

The wheel W is ree-running on the hollow rbour E nd

rottes continuously in enggement with the toothed edge othe tourbillon crrige.The cm C nd fngerF re fxed to E. The wheel K, with its cm,

is fxed to the minute-recording rbour pssing through E.When clutch lever L is rised, spring S will press W into contct

with ces D nd the underside oE to strt the seconds hnd.at ech turn o E the fnger F will engge the intermedite

wheelJto dvnce Kone tooth or ech elpsed minute. WhenW is disengged to stop the seconds hnd, both cms cn bereset by the zeroing levers.

Action of Pillar Wheel

Pressure t A rom the chronogrph button in the cse will

cuse the pillr wheel pwl to slide to the right, down the rmpt B to engge rtchet tooth. Further pressure will dvncethe pillr wheel one tooth. When relesed the pwl spring will

rise the point o the pwl so tht it will be pushed bck to the

let by the slope o the rtchet tooth.The digrms below show the ction engged to the let nd

disengged to the right with cms zeroed.


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Chronograph wrt-watch, four-mnute tourbillon wthDanel co-axal ecapement, invar balance prng wthtermnal curve free prung, chronograph et nto the plateto avod ncreaed heght to the movement. slver dal

wth ubdary dal, for contnuou econd to the rght,chronograph econd wth mnute ndcator to the left,reerve of wndng ector above, gold hand.

Plate I


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Plate II

Watch with on-minut tourbillon with ftn-scond rmontoir,two-armd carriag, rvrsd spring-dtnt scapmnt, stain-

lss stl balanc with rcssd scrws, elinvar balanc spring

with trminal curv, silvr ngin-turnd dial with sctors orequation o Tim and stat o winding, gold hands, ngin-

turnd gold cas. 60 mm diamtr.


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3

FINISHING STEELAND BRASS

Hardening steelSteel is hardened by heating to red heat and cooling suddenly.The hardness can be measured by pressing a hard point into thesurace and measuring the area o the indentation. This is useul ortesting batches o steel used or mass production o components.The watchmaker can learn to assess the characteristics o his steelby testing a small piece beore embarking on the work o making acomponent. It is important to do this with each new piece o steel toavoid errors that could ruin many hours o work.

In principle the steel is heated to red and plunged quickly intowater or oil. There are many dierent shades o red heat and some

steels need greater heat than others. The watchmaker rarely needsa component to be so hard that it cannot be cut with a metal tool.Experiment with the steel and discover the dullest red that willsuce or hardening. Oil-hardening steels are generally betterbecause oil will cool more slowly than water and this will preventthe component rom becoming distorted. Some components willneed protection rom excessive local heating o the more delicateparts. Heavier components o more uniorm density can be helddirectly in the fame.

In watch actories hundreds o components are heated at one timein oxygen-ree urnaces. In this way the pieces are kept clean and ree

o scale caused by oxidation o the surace. The watchmaker doesnot usually have this acility and will need to clean the componentater hardening. This is not much hardship because most piecesneed some orm o special nishing or practical or aesthetic reasons.A variable blow-torch with a fame that can reach a diameter o about20 mm or a length o about 100 mm will suit all the watchmakersneeds. The components are so small that no special heat insulationis needed.

Larger components can be slowly rotated on iron-wire handleswhich will not harden when quenched. Use charcoal blocks tohelp conne the heat. Fig 64 shows a copper box suspended byan iron-wire wrapping. This will need more heat than an exposed


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52 Finishing Steel and Brass

component and will need quenching in water to ensure sucientlyrapid cooling o the component inside. This orm o protection isused to prevent distortion o irregularly shaped, fat components.Keep the coolant close by the torch but never jerk the componenthurriedly into the liquid. The movement through the air will inducea drop in temperature at the leading edge that could cause distortion.

Very small pieces will cool quickly when out o the fame. Holdthem immediately above the coolant during heating, as shown inFig 65. Withdraw the fame beore quenching. It is very rare thata component is so small that it needs to be passed rom the fame

64 Hardening box with iron-wire handle

65 Hold small pieces above the coolant


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Finishing Steel and Brass 53

immediately to the coolant. Withdrawing the fame rst allows justsucient time to ensure even conduction o the heat. Binding withiron wire is usually recommended as a means o distributing theheat evenly. This is a tedious business which does not help robustcomponents, and delicate pieces will almost certainly become bentin the binding. Such pieces are better protected by an iron-wiresheath, as in Fig 66. This is made by winding the wire into the ormo a closed tube around a pencil or similarly shaped object. Thepiece can be saely heated until the sheath is red hot and the whole isthen plunged into oil. This method will unailingly harden detentswithout any danger o distortion.

Plate screws can be held in a loop o iron wire, as shown in Fig 67.Smaller screws are dicult to hold but can be heated in a metal tubesuspended rom wire, as shown in Fig 68. Ater quenching, pouro the oil and immerse the tube in the benzine pot to wash out thescrews.

Pinions are covered in soap and supported in a loop o wire,

as shown in Fig 257. Note that to prevent distortion the pinion isloosely held in the loops with the leaves ree o the wire. Scalingcan be minimized by covering the component with sot soap. Thisis most easily done by immersing in a solution made by dissolvinga tablet o good toilet soap in a little water. Keep this in a sealed jarready or use at any time.

Tempering

It is usual or watch components to be tempered ater hardening. Thetempering is done by heating, which sotens the metal according tothe amount o heat applied. This can be measured by the changingcolour o the metal as the temperature rises.

When possible one surace is cleaned bright with a bu stick oroilstone slip. The piece is held over the fame on a brass plate untilthe required colour is reached. I the component cannot easily bemade bright a separate piece o bright steel can be laid alongside onthe brass plate. This separate steel piece must be o about the samesize and surace area as the component to be tempered.

Most watch pieces can be tempered to a medium-blue colour.This will leave them tough enough to resist deormation without

66 Iron-wire sheath or smallcomponents

67 Iron-wire handle or plate screws 68 Metal container with iron-wirehandle or small screws


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being too hard to work with metal tools. Harder tempers or toolsor components subject to wear by riction are described later asappropriate. Irregularly shaped or very delicate pieces can betempered more uniormly in boiling oil, but this should be done ina well-ventilated place.

Finishing MaterialsDiamantine PowderThis is a ne, white, crystalline powder, produced during themanuacture o articial jewel stones. When properly applied tothe surace o hardened steel, it will produce a brilliant polishedsurace devoid o scratches or grain. To achieve a perect polish withdiamantine requires some practice but success will be the more surei the powder is properly mixed. The powder is mixed with thinoil on a steel or glass plate to the consistency o moist putty. Whennot in use it must be kept covered and ree o contamination bydust. Only a very small amount o oil is required to mix the powder

into the desired consistency but this is by no means apparent in theearly stages.

Place some o the powder on the mixing plate. A little heap oabout 10 mm diameter will be enough. Make a hollow in the top othe heap and put in one drop o watch oil dripped rom a rod o about2 mm diameter. Mix the powder rom the edge into the oil until itis no longer fuid. With a sti, fat, steel spatula, made thoroughlyclean on all sides, scrape the powder into a small heap again andpress it down fat with the spatula. This process will distribute the oilthroughout the powder and at the same time crush down the largergrains. It must be repeated many times until the oil is completely

absorbed. At this stage the crushing action o the spatula can bechanged to a beating action on the top o each reshly ormed heap.I, ater ve minutes work, the mixture remains dry in appearance,a tiny drop more oil may be added and the process repeated untilthe mixture becomes a very thick paste o the consistency o moistputty. In this condition the oil will be thin enough throughout thepaste to dry up under the action o the polisher, without whichaction the best polish cannot be achieved. With practice it is possibleto obtain a polish so ree o grain and scratches that, when the workis turned to refect the light away rom the eye, the surace looksquite black.

Some o the success o diamantine polishing can be attributed tothe quality o the powder. The coarser powders, more crystallinein appearance, usually produce the blackest polish when properlycrushed.

Water-of-Ayr StoneThis sot, ne-grained stone is easily cut and led to shape orspecial purposes. It is used or fattening and smoothing thesurace o brass plates to remove scratches and machining marks.It can be obtained in lengths o square sections o various sizes.A piece about 150 mm in length by about 12 mm square is mostsuitable or watchwork. When new the suraces are ribbed with


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cutting marks and these can be removed with a le while thestone is held under water. The stone should be kept thoroughlywet all the time it is in use. Failure to do so will result in brightspots o metal appearing on the surace o the stone which willscratch the work. The simplest way o avoiding this is to rest thework on a cork block beneath a tap running with a thin trickleo water.

I the work is greasy, as is most likely with a piece in course omaking, wash with soap and water beore applying the stone. Holdthe stone in fat contact while rubbing with short strokes. When thewhole o the working surace o the stone is elt to be in contactturn the work through 90 and recommence the stoning until thesame sot, smooth contact is elt between the two. Turn the workrequently to ensure fatness o the surace and ensure that theworking ace o the stone remains in ull contact as the tip o thestone passes over the edges o the work. Continue until the surace isquite smooth and ree o scratches when it will be ready or whatever

nal nish is to be applied. The pressure applied to the stonemust be just sucient to keep it in contact with the work. Heavierpressures will cut aster but leave a coarse nish. Do not scrub thesurace o the work with a circular motion or this will cause deep,curved scratches.

Bluestone

This has a ner grain than water-o-Ayr stone and does not cutso quickly. In the past it was used principally or polishing brasswheels. Two bluestones are rubbed together with thin, clear oil toproduce a thick paste. The paste is applied to the ace o the wheel

with a wood polisher.

Oilstone

Sharpening stones, manuactured in conveniently sized blocks witha coarse surace on one ace and a ner surace on the other, areused or orming cutting edges to hand tools. They are an importantworkshop tool and should be treated with care i the best results areto be had rom them. The surace in use should be kept clean andliberally oiled. The cutting action is improved by regular cleaningwith petrol and a sti brush to remove blackened oil.

Proper use o the oilstone in the early days, when learning to

turn, will make the dierence between a good and bad turner. Thebeginner should cultivate the eeling that his use o the stone is parto the process o making a watch and devote to it as much care ashe will to the manuacture o the separate components. Once he hasmastered the technique o using the stone, with the correct pressureand speed o motion o the tool to be set, the work can be completedwith remarkable ease. To a good workman the appearance o aperectly fat tool ace is part o the pleasure o his daily work and isa direct contribution to its quality.

Small slips o various shapes and sizes can also be obtained orsmall nishing tasks at the bench. They are particularly useul orfattening small, steel components ater hardening.


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Oilstone PowderThis ne-grained grit is used principally or smoothing the suraceo hardened steel prior to applying the nal polished nish. To use,mix it with thin oil to the consistency o a thick, wet paste. Do thison a smooth, steel block. Always keep the paste covered when notin use to prevent it coming into contact with the working area o thebench and thus contaminating the work.

Degussit StonesThese hard stones are made rom mixed crystals o aluminium oxideand chromium oxide and can be obtained in a variety o shapes andsizes. Smooth or coarse suraces are made or each shape. They willretain a sharp edge and are especially useul or reaching into sharpcorners when nishing steel components.

Polishers for Oilstone PowdersSteel or iron polishers are used or applying oilstone paste. Rolled

steel is better able to resist deormation o the sharp edge and willproduce a sharper corner to the work. The size o the polisherdepends on the size o the work and a correctly sized polisher willenable the surace to be sensed through the polisher as the workprogresses.

When polishing work in the lathe or turns, long polishers oabout 180 mm in length are advantageous in helping to keep theedge square with the ace. Three strips o dierent widths, withthe ends prepared as in Fig 69, can be used double-ended, thusmaking six polishers available or general work. It is not necessaryto have a fat ace in contact with any shoulder o the work. The

edge should be dressed to a sharp corner at an angle away rom thefat ace. Provided the work is turned cleanly with a sharp graverinto the corner, the angled edge o the polisher will reach into thecorner and leave it equally sharp ater the smoothing action othe powder.

The width o the polisher or general work enables the orengerto rest on the top surace and keep the polisher in fat contact withthe work. For smaller work, such as the short arbors o pinions,suitable shapes and sizes o polisher can be made when requiredand soon a collection o polishers will be accumulated that will copewith all sizes o work.

Round steel wire, led to a hal-round section, will make a goodpolisher or small work. File the end fat as in Fig 70. This willproduce a slight taper throughout the working length, both inthickness and width, which will improve the balance and eel othe polisher. File the working ace fat by resting the polisher onthe orenger and stroking the le, as shown in Fig 71. There is noadvantage in dressing any polisher by ling across the surace. Todo so, especially with a sharp le, is to risk putting the surace outo fat. Filing at an angle across the ace will produce a fat suracewith the greatest area in contact with the work and with maximumfow o the cutting paste.

The need or a used le when dressing the surace is important.

69 Hard-rolled steel polisher orwork sharp corners

70 Steel or brass rod polisher


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The le should not be so worn as to need excessive pressure tomake it cut, or this would produce a shiny surace with poor pasteretention. On the other hand a sharp le is liable to rock the polisher

by biting too ercely at the edges, thus producing a roundedsurace. The rounding would be too small to see easily but would

be enough to make the polisher slow and uneven in action. I a newle is used there is a risk o tiny pieces o hard steel chipping othe le and becoming embedded in the surace o the polisher tocause bright scratches in the work. Choose a le that will cut witha light pressure without biting the surace o the polisher. Such ale will produce a ne, dull-grained surace with maximum abilityto hold in fat contact with the work. When prepared in this waythe polishing action will be satisyingly smooth to the touch andthe even distribution o the paste will oer a light resistance to thestroke o the polisher.

Only a very small amount o paste is required on the polisher,which is charged by dabbing it lightly on the mixing block. The

quantity will be judged by experience but as a general guide, atera dozen strokes, the polisher should display an even coveringo smooth, moist, crushed paste with no uncrushed grains atthe edges. A urther two dozen strokes will dry up the pasteand leave the surace o the work with a smooth, bright-greysurace.

Bright ridges on the work and corresponding pressure marks onthe polisher indicate badly turned work. To attempt to remove themarks with the polisher will result in the loss o the corner o bothpolisher and work. The ridges must be turned away with the longedge o the graver beore polishing starts.

Do not press the polisher into hard contact with the work. Thiswill simply sweep the powder away to the edges o the polisherand thus leave insucient to do the work. A light pressure will givethe powder time to spread over the whole surace and crush downevenly. As the polisher is moved lengthways over the work it should

be biased rom side to side to keep the paste fowing over the entirelength o the work.

The speed o rotation o the work and the length o stroke othe polisher should be related. Here again experience is essentialto produce good work quickly. A general guide is to use strokes oabout 40 mm to 50 mm length o the polisher and, when using a

bow, three single strokes in two seconds will produce a satisactoryspeed o rotation. For small work increase the speed and use shorterstrokes o the polisher which, being narrower, will require extracontrol o the sideways motion. The nish rom the oilstone powderis the oundation or the nal polishing with diamantine and the

beginner must perect his technique i he is to achieve the nalperect nish.

In addition to these simple, fat, polishers the watchmaker willoccasionally need circular laps, acing tools and a variety o smallhand polishers or nishing irregularly shaped components.These, and their methods o use, are described and illustrated asrequired.

71 Filing the polisher fat


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Polishers for Diamantinesteel The steel polishers used or oilstone dust can also be used orpolishing with diamantine. The polisher is charged with the mixedpaste by a light touch so that a small amount is transerred to thefat ace. The edge will be charged by the spread o the diamantineduring the polishing action and this is sucient to polish a shoulder.The speed o rotation o the work and the length o the polishingstroke are important i the best polishing action o the paste is tobe obtained. As when using oilstone dust, a polishing stroke o40 mm to 50 mm and a speed o rotation equivalent to three singlestrokes o a bow every two seconds will serve as a guide to thebeginner.

Use a light pressure on the polisher to allow the diamantine tospread and crush evenly. Do not keep the edge o the polisher incontact with the shoulder o the work but allow it to touch on eachthird or ourth stroke only. Allow the polisher to wander along thelength o the work to prevent the ormation o circular scratches.

The condition o the surace o the work can be seen as the polisheris moved sideways during this action and, i the pressure andspeed are correct, it will be covered with a black, moist paste. Asthe polishing progresses this paste will dry and leave a smooth,bright, polished surace. At this moment the ace o the polisherwill be quite dry and covered with a thin skin o exhausted paste.I the work is not satisactorily polished the polisher cannot nowimprove it without rst being cleaned and re-charged with reshpaste. Further rubbing with a dried polisher will cause the suraceto roll into hard lumps that will scratch the work. The best polish isobtained when the surace is ree rom scratches at the moment the

polish dries.

bell metal Even when using proven diamantine with correctpressures and speeds a perect polish cannot always be obtainedwith a steel polisher. The type o steel used and the degree ohardness o the work can infuence the quality o the polish and maycall or a dierent polisher. Bell-metal polishers can be used whensteel is unsuitable. Some grades are harder than steel and will keep avery sharp corner which makes it particularly suitable or polishingin the turns or lathe. A sharp le is needed in dressing the surace,with the polisher resting on the nger, as shown in Fig 71.

Bell metal is a copper and tin alloy and when rubbed on steel it willnot so readily mark the surace by welding at the pressure points,as can happen when two steels are rubbed together. This, combinedwith its resistance to deormation at the sharp edge, makes it ideallysuited to polishing tempered steel. It should be used in exactly thesame manner as a steel polisher.

brass Free-cutting brass rod led to a hal-round section, similarto that illustrated in Fig 70, will quickly produce a fawless, nalpolish to small pieces such as balance stas, wheel arbors andsteady pins, etc., that have been brought to a good surace with thesteel polisher. Useul rigid polishers can be made or glossing the


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bevelled edges o small components by soldering a strip o zinc tothe fat o the brass rod polisher.

zinc Zinc is used also or polishing fat suraces. Two pieces,one about 75 mm square and one about 150 mm square, will serveor both small and large work. Prepare the surace by ling fatwith a le well charged with French chalk to prevent clogging andconsequent scarring o the blocks surace. Finish with water-o-Ayre stone under running water. Ater use the skin o exhaustedpolish can be wiped away with a cloth moistened with benzine andthe surace re-used.

tin Tin polishers are used or gold, brass and other sot metalsbut are equally useul or polishing large, steel suraces. Because themetal is very sot and lacks resistance to bending the polishers needto be quite large and are thereore heavy. A useul size or polishingwheels, etc., while they are resting on a cork block, would be 120 mm

long by 15 mm wide by 5 mm thick. This can be ormed by pouringthe molten metal into a plaster mould o suitable dimensions. Whilemolten in the ladle, remove the scale and impurities rom the suracebeore pouring.

Tin polishers are not suitable or polishing up to a corner, or theedge will soon become deormed. Only the ace need be preparedby ling fat with a large, coarse le and ollowing this with a worn,smooth-cut le to remove the scoring. A lighter polisher or usewhen polishing mounted wheels in the turns or lathe can be madeby laying a piece o hard, fat brass in a smaller mould and thenpouring in the molten tin. The brass will add stiness to the polisher

to prevent bending under pressure.

wood Willow-wood can be used or polishing mounted wheelsand will quickly produce a bright polish. It is important that the aceo the wheel is quite ree o scratches beore using willow or theextended use o wood will put the surace out o fat by rounding ittowards the teeth.

Burnishers

Burnishers are les with very ne cutting suraces generatedby rubbing them on coarse emery paper or a piece o hard wood

covered with emery powder mixed with oil. It is important that thecorners are kept sharp and square during sharpening, especiallywhen they are used or polishing pivots with square shoulders.

Small burnishers are easily made to any convenient shape orpolishing the bevelled edges o small components or improving thesharpness o pierced corners. Keep liberally oiled in use to preventthe surace clogging and scratching the work. Silver steel is excellentor this purpose. File the steel to the required shape and leave theworking suraces with a cross-led surace. Heat to bright redand drop into water. Sharpen the led suraces with emery paperwrapped around a curved surace to prevent the edges roundingand the burnisher is ready or use. Alternatively lay the burnisher


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on a piece o cork and rub cross-ways with a coarse oilstone. Thiswill generate a good, sharp, fat surace.

Sapphire FilesThese are oten recommended or use as pivot les and, used withplenty o oil, will certainly reduce a pivot diameter very quickly.They easily suer rom chipping at the edges when they will leavea ridge at the root o the pivot. The edges can be sharpened only ona diamond lap.

Because the sapphire is brittle and easily broken it should be keptshort; about 20 mm in length will allow a thickness o about 2 mmtapering to 1 mm or a width o 3 mm tapering to 1.5 mm. It should

be cemented into a thin handle o about 100 mm in length and ttedwith a cap to protect the burnisher when not in use. It is reallyhardly worth the trouble o preparing and a steel burnisher willproduce a better result just as quickly. I a pivot needs more reducingthan can be achieved with a steel burnisher or an iron polisher the

work will be more satisactorily done with a graver in the lathe ora pivot grinder.

PolishingComponents made in the lathe or turns usually require polishingas the work proceeds. The methods used are described underthe appropriate heading or the component and consist entirelyo polishing turned suraces and shoulders while the workis revolving.

Irregularly shaped pieces will sometimes need to be revolved butor the most part can be polished while stationary, either underhand

or held in the hand while the work is done by the polisher.

Swing Tools for PolishingSwing tools were much used at one time or polishing fat the manyacets o irregularly shaped components and especially springdetents. Essentially the tool is a pivoted jig capable o holding thesurace to be polished level with the centre o motion o the pivots.As the polisher is raised or lowered with the movement o the handthe tool will tip to keep the work fat to the polisher. An example osuch a tool, set up to polish the impulse ace o a roller, is shown inFig 301. Note that the surace to be polished is set in the clamp level

with the pivots. The tool can be pivoted in the turns or, as was moreusual, in a bracket held in the vice.In days gone by watch and chronometer makers specialized, or

reasons o economy, in one particular branch o their crat. As aresult it was possible or a workman to develop swing tools and

jigs especially adapted to his work. With their aid he could polishquickly, and without risk o mishap, the separate fat suraces o thepiece in course o nishing. No doubt the men who used them werequite capable o polishing a surace fat and square without themand it may be that the speed with which the work could be executedwas the principal actor in their use. It is certain that i a man canproduce a perectly polished surace he is suciently experienced


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to be able to do so without the aid o a swing tool. To be properlyuseul the tool needs to be well made and its construction willtake longer than the time taken to develop the ability to polishthe surace without it. I do not regard them as essential to watch-making and believe that excessive use o such tools may have beenresponsible or the mechanical squareness seen in so much lateEnglish work.

Mounted Brass Wheels

These need both revolving and underhand polishing. First polishthe spokes with hard wood cut to reach into the corners and chargedwith rouge. Rouge can be bought in blocks or use on polishingmops. Scrape fakes rom the surace and mix into a thick pastewith oil.

The ree-hand use o the polisher to the spokes and inner rimwill give a rounded edge to the work. For nineteenth-century,Continental work with curved bottoms to the spokes the rounded

edge refects the style o the spokes to give a pleasing eect. It doesnot look so convincing with English straight spokes and should bekept to a minimum.

Polish the aces o the wheel with wood polishers and bluestonepaste or rouge. The wheel is pivoted in the turns and rotated with abow. Both strokes o the bow are used. Rub two sticks o the stonetogether with oil to produce a smooth paste. Prepare the polisher sothat it is fat and smooth. A le is usually recommended or this butis inclined to le a curve into the polisher so that the wheel polishesmore quickly at the edges and becomes domed. A carpenters smallnishing plane will produce a fat surace quickly. Hold the polisher

in the vice and make one steady pass over the surace to be cleaned.For small polishers grip the plane bottom-side-up and draw thepolisher over the blade.

Boxwood will produce a fat polish but soon becomes chargedwith brass and causes scratches. Do not allow the polish to drybeore the work is nished. A dry polisher will immediately becomecharged with brass, a condition which is easily seen in the orm obright, brassy streaks on the surace. These must be removed beorecontinuing the work.

Willow-wood is close-grained but soter than boxwood. I usedtoo vigorously it will cause the teeth o the wheel to become rounded

at the edges. A good compromise is to use boxwood to make thesurace smooth, and willow to nish to a polish.Diamantine should not be used lest it becomes embedded in the

teeth when it would cut the pinion leaves. Work the bow at abouttwo strokes per second with the polisher moving in the oppositedirection. Clean the surace with bread kneaded with oil and nallywash in benzine and dry in warm, boxwood dust.

I the wheels need a circular grain this can be applied with a sticko water-o-Ayr stone, lubricated with oil, or pumice powder and oilon a wood polisher. Water can be used or this. Wash the nishedcomponent in clean water, and nally rinse in methylated spirits toabsorb the water. Dry in warm, boxwood dust.


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Unmounted Wheels

Ater polishing the edges o the spokes lay the wheel on a fat, corkblock and polish with wood. Turn the block through 90 ater everyhal-dozen strokes o the polisher. When one side is completed cleano by washing in benzine. Wash also the surace o the cork withbenzine on a brush. When dry smear the surace with beeswax.Lay the wheel on the beeswax and polish the second side. Thebeeswax will hold the wheel stationary and prevent the polishedsurace becoming scratched. Clean o with benzine and dry inboxwood dust.

Use a tin polisher or escape wheels. Prepare the surace with ane le and nish with waterstone under running water. Use rougeor ne, moist diamantine, both o which will produce a brilliant, fatsurace. Alternatively the wheel can be polished underhand on a tinblock, as shown in Fig 72. Cement the wheel with shellac to the discwith sunken centre to bring the point o the rod low down to thesurace o the wheel. Move the wheel with a circular motion o the

rod over the area o polish until the surace contact is smooth andsilent. Detach the wheel by boiling in methylated spirits.

Wheels must be thoroughly washed ater polishing to remove alltraces o paste that could mark the pinions o driven components.At one time this was done most eectively with bread kneaded withoil into a dough. Proprietary tacky materials are now available anddo the same work more conveniently.

Screws

To polish the end o the thread hold the screw in a lantern holder,as in Fig 73, and rub on wood charged with diamantine. Rotate the

holder between the ngers while sweeping the length o the wood.The holders are made or broaching the pipes o seconds hands

and need to have the hole in the thread plugged when very smallscrews are being held. The heads can be polished by the samemethod but with the thread held in a pin vice. Alternatively theycan be polished while spinning in the lathe.

72 Polishing small wheels on thetin block

73 Polishing the ends o screws on a wood block


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Polishing HandsPolish the shank or needle o the hand rst. Ensure that the cornersare quite sharp rom the clean edge o the nishing le. Unsharpcorners will take on an exaggerated appearance ater polishing.

Use iron polishers with oilstone paste to smooth away the lemarks on the shanks o steel hands. Hold the hand by the bossas described when making. Polish with diamantine on a brasspolisher. Use a tin polisher with sharp diamantine or gold hands.For both gold and steel nish with ne diamantine on a boxwoodpolisher.

Smooth the fats o steel hands with iron polishers and oilstonepaste. Finish with diamantine on zinc polishers. Use a tin polisheror gold. Rest the work on cork cut away to give reedom to thepolisher, as shown in Fig 74. The pipe can be pressed into the suraceo the cork. Where there is no projection to hold the work steadysmear the cork with beeswax. Press the component on to the waxand briefy lay a warmed burnisher on the surace to make it stick.

This method o holding the work is particularly useul or smallpieces such as endcaps and spring studs, etc.

Both the boss and counterweight o a seconds hand can be polishedat the same time, as shown in Fig 75. This will ensure a single, fatrefection rom the polished suraces.

Bolt ToolHand bosses that are too small to remain fat on a cork can bepolished underhand while held in a bolt tool, as in Fig 76. Thissmall, general-purpose, polishing tool is oten very useul as anaid to fat polishing. Made o brass, it should be thick enough to

resist bowing under pressure and shaped as illustrated to allow alight grip between the thumb and second nger while the orengermaintains a downward pressure. The screws should be hard at theresting tips and slightly domed to prevent scoring the polishingplate. Note that the screws are a riction t in their threaded holesso that small alterations in height can be made without havingto clamp the screw ater each movement. The tool is used on thezinc plate with the work clamped under the end plate or waxedto the underside. It is principally used or polishing fat screwheads and delicate, irregularly shaped pieces such as returnsprings.

Carriage BridgesWhen the length o a curved surace is bounded at each endwith a step, care must be taken to avoid orming a ridge at thecentre, as shown in Fig 77. This will occur i the polishing strokeis made with the edge o the polisher in contact with the step.Avoid this by moving the polisher diagonally along the length othe surace. The condition will not be seen by the inexperiencedwhile the work is in progress. Only when the piece is cleanedand light is glinting along the surace will the ridges show. Theymust be removed with a ne le and the work o polishingrecommenced.

74 Polishing fat on a cork support

75 Polishing separate suraces plane

76 Bolt tool

77 Suraces ridges caused byincorrect polishing action

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