Watchmakers Lathe Question

[Shaun ChurchillParticipant @shaunchurchill54517]

I have just finished refurbishing this neat little watchmakers lathe and wondered if anyone can advise me what type of collets are likely to fit in the headstock spindle and similarly what type of tooling fits in the tailstock – not even sure if there is a taper in the tailstock bore?

Also any advice about what kind motor rpm I would require to drive the lathe.

The main aspect of the refurb was making a complete new lathe bed out of gauge plate. Most of the milling was done on my Tormach CNC which just goes to show these hobby machines are capable of milling more than just plastics and aluminium!

Thanks in anticipation.

 

[bernard towersParticipant @bernardtowers37738]

That looks like a nice job, I think watchmakers collets go by the largest capacity ie 6mm/8mm 10mm but overall dims must be avail somewhere try lathes.co.uk site. If you look up COLLETS on that site theres quite a bit of info and diagrams.

[Roderick JenkinsParticipant @roderickjenkins93242]

Watchmaker collets are defied by the diameter of the parallel portion of the collet body.  While many makers made 6/8/10 mm collets, the head angles and draw tube threads can be subtly different so careful measurement is necessary to determine the correct collet.  Have you any idea who made the original headstock/spindle?

Rod

[Shaun ChurchillParticipant @shaunchurchill54517]

Thanks for the replies thus far.

All I have measured is the bore of the headstock spindle and its clearance on 8mm diameter. I can make a draw tube in due course. There is a key in the spindle bore as one would expect to see.

Alas, there is nothing to identify the maker of the lathe.

I will get my loupe out and look up the bore of the tailstock barrel.

[BazyleParticipant @bazyle]

That appears to be a homemade bed for a common mfr’s headstock. The maker’s name is often on the back end of the headstock. If missing all I can say is it is not Boley-leinen.
The tailstock barrel is often interchangeable ie a watchmaker might have several with and without taper.

[Shaun ChurchillParticipant @shaunchurchill54517]

The original lathe bed was very home made so to speak and although its outer surfaces were all ground, the standard of milling on the underside was like a first year apprentice had been let loose with a mill. Bazyle you are most probably right, the other bronze parts are of extremely high quality which suggests they were professionally made. I didnt for one minute think it was a Boley Leinen lathe, but happy to have got it for little money and have the opportunity to put it back into use. So if the tailstock barrel doesnt have a taper fit, what kind of tooling will fit the barrel?

[BazyleParticipant @bazyle]

By the way have you checked whether the current item in the tailstock fits the headstock – it might be the draw tube if it is internally threaded.

In the tailstock instead of a taper into which you insert eg a pointed centre since it takes little metal you might have dedicated rods finished with centres of different sizes, half centres, cups, threaded ones for a chuck, holder for Jacot tool etc.

Check https://www.lathes.co.uk/watchmaker/

 

[DellParticipant @dell]

If the bore of the spindle is 8mm then check the bore at the back of the spindle because for an 8mm headstock the spindle bore should be slightly larger I would think, it so for my Pultra tailstock I can’t measure the headstock as it takes 10mm in the headstock.

[Shaun ChurchillParticipant @shaunchurchill54517]

The spindle bore where the collet key is situated is about 8.03 / 8.04 mm in diameter. Beyond this section the diameter increases to around 8.75mm which I assume is for the register portion of the collet tube to engage in. I have since poked various imperial, metric and number size drill blanks into the bore of the tailstock barrel and there is most definitely a shallow taper in the bore.

[Shaun Churchill]

On Shaun Churchill Said:

The original lathe bed was very home made so to speak and although its outer surfaces were all ground, the standard of milling on the underside was like a first year apprentice had been let loose with a mill. Bazyle you are most probably right, the other bronze parts are of extremely high quality which suggests they were professionally made. I didnt for one minute think it was a Boley Leinen lathe, but happy to have got it for little money and have the opportunity to put it back into use. So if the tailstock barrel doesnt have a taper fit, what kind of tooling will fit the barrel?

The tailstock might take “runners” which are just straight shanked tools usually held in place by clamping a lever on the tailstock.

[DellParticipant @dell]

Sounds like the headstock takes 8mm collets & the tailstock is just for runners , if you use the tailstock for drilling then you would need something like this.

the runner usually has a 2 deg taper

[James AlfordParticipant @jamesalford67616]

I am happy to confess my ignorance. I have never come across runners before. If used for drilling, what stops them from spinning and how are they moved in to apply pressure to the drill bit? My Flexispeed has a groove milled down the length of the tailstock shaft and a locating pin to keep it still, and a threaded handle to advance it.

James.

[Michael GilliganParticipant @michaelgilligan61133]

This handy table has been plagiarised elsewhere, but I believe it is due to

Ward L. Goodrich.

The Watchmakers’ Lathe

Its Use and Abuse

.

.

.

MichaelG.

[Shaun ChurchillParticipant @shaunchurchill54517]

I really appreciate all the comments so thanks to all those who have provided their five penneth worth!

I can now understand why a tutor of mine as an apprentice toolmaker was so smitten on watchmakers lathes. This has opened up a whole new world of engineering that I confess I knew very little about. Having looked many a time at the Lathes.co.uk website at the commercial machine listings, I had no idea that there was an equal abundance of watchmakers lathe data on the website.

When I purchased the watchmakers lathe my intention (rightly or wrongly) was to turn it into a cylindrical between centres grinding attachment to use on my two surface grinders, but now I want to actually use the lathe as it was intended – all be it not for making watch parts.

Cheers,

Shaun

[Michael GilliganParticipant @michaelgilligan61133]

That’s a great outcome, Shaun !

If you haven’t already done so… I suggest you grab the PDF of that Goodrich book

There’s a lot of interesting stuff in there.

MichaelG.

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Ref. http://www.opensourcemachinetools.org/archive-manuals/watch_makers_lathe.pdf

[SillyOldDufferModerator @sillyoldduffer]

Michael’s table showing DIMENSION OF CHUCKS OF VARIOUS MANUFACTURERS illustrates an awkward problem, which is that Watchmakers Lathes aren’t standardised!

Less of an issue when the lathes were new, because customers knew what they were buying.  And the lathe came with a set of accessories, often seriously expensive:

Back then repairing mechanical clocks and watches was big business, so large numbers of lathes were sold.  Many not particularly well-made or supported, others excellent.  Unbranded lathes seem quite common.

As time passed, clock repairing as a business went into decline, so many lathes became unloved, badly stored, separated from their accessories, or scrapped.  Decades later, we pick up the survivors, and finding out what it is can be difficult.  Not even obvious how they were used.

I think Shaun will have to carefully measure his head and tailstock.  With luck they match one of the well-known makers.

Though I came close to taking up clock-making as a hobby and swotted up, I don’t have a feel for the minimum number of accessories needed to get going.   Building a clock, I guess much could be done with a few collets and a shellacked faceplate.  Repairing old clocks for money might need a lot more because shapes and sizes vary so much.  Can a clockmaker advise please – what else does Shaun need to get his lathe operational?

As an aside, I’ve watched many episodes of “Repair Shop” whilst caring for mum.   They have a Myford in the background, which is never used!   In contrast, a watch-makers lathe gets lots of screen time.  Unfortunately they don’t explain or show the accessories.   Might all be done with a one graver and a single collet, but I suspect there’s a drawerful of collets and other goodies off-screen.  TV isn’t good at techie subjects.

Dave

 

 

 

[DellParticipant @dell]

Yes there are quite a few accessories here is my English Pultra P type it has a headstock that takes 10mm collets & a tailstock that takes 8mm collets as well as runners, if you use a runner for drilling the taper in the runner is a bit like a Morse taper self gripping & using the runner to drill give very sensitive feel when using sub 1mm bits, have a look at my YouTube channel @torsiondell you will see how I use my Pultra.

[PeteParticipant @pete41194]

Very nice lathe Dell.

That’s not the first time I’ve seen it mentioned that some accessories for watch maker lathes may not be standardized for some items. While I’ve never used those 6/8/10 WW designated collets. I’ve also read posts where the collets threads between the various manufacturers may not exactly match for there finished thread flank profile and thread minor diameters. So not all draw tubes can be used for all collets even when there the same O.D. and taper. If I recall correctly, T.D. Walshaw mentioned the same in one of his books. Maybe something worth keeping in mind for anyone buying used collets.

Fwiw and if I wanted to be 100% positive of what I had for a spindle or collet taper. There’s a product designed to do exactly that. A low melting point alloy. The common brand name in North America would be Cerrocast or Cerrosafe. It might also be known elsewhere as Woods Metal. https://en.wikipedia.org/wiki/Cerrosafe There’s multiple temperature ranges from about 117F – over 400F. The better brands have controlled alloy amounts with known percentages for shrinkage rates immediately after casting, or on a percentage graph for the hours since it was cast. Because of that, very accurate measurements can be taken.

[DellParticipant @dell]

If your headstock turns out to be 8mm then this maybe of help but the most common thread is 275 X 40 tpi.

[James Alford]

On James Alford Said:

I am happy to confess my ignorance. I have never come across runners before. If used for drilling, what stops them from spinning and how are they moved in to apply pressure to the drill bit? My Flexispeed has a groove milled down the length of the tailstock shaft and a locating pin to keep it still, and a threaded handle to advance it.

James.

A drilling runner will usually have a knob on the end which you literally just push through the tailstock to advance it into the workpiece, your grip is all that stops it spinning.

You have to understand that a watchmakers lathe is a very light duty machine. Most users will only ever drill very small holes, often just a fraction of a millimeter. The maximum size of drill bit used probably never exceeds about 6mm.

[Clive SteerParticipant @clivesteer55943]

Donald De Carle wrote a very good book about The watchmaker’s and model engineer’s printed by Hale. The book has a comprehensive description many lathes, their attachments and details about their use.

CS

[Hollowpoint]

On Hollowpoint Said:

On James Alford Said:

I am happy to confess my ignorance. I have never come across runners before. If used for drilling, what stops them from spinning and how are they moved in to apply pressure to the drill bit? My Flexispeed has a groove milled down the length of the tailstock shaft and a locating pin to keep it still, and a threaded handle to advance it.

James.

A drilling runner will usually have a knob on the end which you literally just push through the tailstock to advance it into the workpiece, your grip is all that stops it spinning.

You have to understand that a watchmakers lathe is a very light duty machine. Most users will only ever drill very small holes, often just a fraction of a millimeter. The maximum size of drill bit used probably never exceeds about 6mm.

Thank you for the explanation, Hollowpoint.

James

[Peter Cook 6Participant @petercook6]

If you are interested Jerry Kieffer described (over on the NAWCC forums) a simple tailstock runner designed to assist with close control of micro drilling on the watchmakers lathe. It is in effect a simple runner to hold the drill with an  adjustable stop to facilitate peck drilling.

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