Help removing a stuck face plate from a watchmaker's lathe

[DocOpera]

Greetings!

I have a Boley & Leinen 8mm Reform lathe that I purchased not too long ago. It has been disassembled and cleaned. Interestingly, as a precursor to what I am about to relate, I have noticed that most of the split wire chucks I've used go in (and can be removed) with great ease. But there are one or two that give some resistance (all properly marked Boley & Leinen). I've checked the threads for debris or rust, but couldn't find anything. The feeling putting them in is as if there's some kind of metal grinding as I screw it in. (maybe something to do with the chuck key?) Anyway...

I was using the universal face plate yesterday for the first time and I encountered that same sort of metal grinding resistance while screwing it into the draw-in spindle. with a little effort (emphasis on little) I did eventually get it in. After I finished working I tried to remove it and...no luck. It is not budging one iota. I put on protective, non-slip gloves and alternately tried turning the draw-in spindle nob and the face plate. No movement whatsoever. I also tried holding the pulley while trying to turn the face plate. No luck. In desperation I sprayed some WD40 inside the hole at the back of the spindle and on the area between the chuck arbor and the front house bearing. I let that sit for awhile and, as a last resort, I wrapped some rubber around the draw-in spindle nob and used locking pliers/ vise grips to try and turn the draw in spindle while holding the face plate. All I managed to do was damage the nob. So, before I add insult to injury...does anyone have any suggestions on how I might get the face plate out? I would be very grateful!

Thank you!

~ Jeff

 

[richiec]

tap it with a plastic hammer?

 

[karlmansson]

So the drawbar handle doesn't move in relation to the spindle/face plate? Richies suggestion is good, tap the end of the draw bar with a plastic hammer, or very light, Sharp taps with a brass one. If you manage to turn the drawbar, undo it about a turn and then tap the end of the drawbar to knock the collet part of the faceplate free of any binding.

Best of luck!
K

 

[karlmansson]

From your Picture it looks a lot like the collet is seating very early on the cone. Are you sure the face plate is made for this lathe?

 

[gmorse]

Hi Jeff,

It may be that the locating pin in the spindle throat is damaged in some way, so that it doesn't fit smoothly in the groove in the shaft of some collets. I know it's easy in hindsight, but if a part doesn't fit smoothly, it's very tempting to try and press on regardless, rather than stopping to wonder why that should be!

I think Karl's suggestion to try some gentle tapping is the best way to free this up.

Regards,

Graham

 

[DocOpera]

Thank you all for the replies.

So...you want the good news or bad news first? Actually, there is no good news, except for the fact that I finished the tool I was working on and learned a painful (and expensive) lesson. I relate it here in the hope that it may help prevent someone in the future from doing what I did.

I'm a novice watch repairer, with about two years of experience. I am self taught. I've read (and understood) Fried, de Carle, the Chicago School of Watchmaking, as well as Perkins (The Modern Watchmaker's Lathe), along with many other treatises on watchmaking. Somewhere in those pages was something to the effect, "when undertaking a new procedure, THINK before you act". That thinking should have started when the face plate (and the wire chucks before) were not going in easily. But now we move from that first warning to my present calamity. I hate to even say it, because it is so embarrassing and obvious now "after the fact".

I got out my trusty vise grips and wrapped some rag around the "post" and with that secured in place, I put a length of hardwood between the clamps of the face plate. (you see where this is going)

Using some rather simply physics, I gently began to use my lever. Eureka! It works! A bit stiff, mind you, but it works. Strange how it didn't just "release" and let me screw it off the rest of the way. Yes Jeff, you genius, that's because you clamped down your vise grips on the back end of the front housing bearing instead of the bit of metal to the left that is part of the draw bar (draw-in spindle). By doing that you locked the front bearing in place and the chuck key along with it. Then by using your lever to turn the face plate, you got it unscrewed, but you also sheared off the chuck key at the same time.

You ever get that sort of sick feeling in your gut when you break (ruin) something? I've already had that since this all started a couple of days ago. Well, now you can multiply that a few times, and that's what I feel now. Sick, sick, sick. I might be able to salvage the face plate with some work, but I've ruined the lathe. The drawbar is securely stuck inside the bearing (no doubt there was distortion to the back end of the bearing from using the vise grips). It's just a train wreck and now I have no lathe. Absolutely sickening. But there it is in all it's gory detail.

So what was I working on when this all happened? I've been working on a Waltham model 1894 Riverside pocket watch and needed to do some hairspring work. I had just finished making a tool in de Carle's "Practical Watch Adjusting" (pgs. 45-46) for use on hairspring pinning/ adjustment. I used the face plate so I could make final adjustments to the brass disc I had made. I've included a photo of my finished tool.

Small comfort for the loss (destruction) of my lathe.

 

[glenhead]

Ain't no thang. Relatively so, anyway. Yeah, it's a stomach-falling-through-the-floor moment, but it's a fairly simple repair. (Go ahead, ask me how I know this. It's why I have two Peerless headstocks. I don't remember exactly how I did it, but the pin-go-bye-bye result was the same.)

There is a synopsis of overhauling a Peerless watchmaker's lathe in post 21 of this thread:
Lathe overhaul procedure

Yours isn't a Peerless, but the watchmaker's lathes I've seen have mostly been roughly the same-ish for teardown and reassembly. (Was that enough qualifiers?) One of the classes I helped teach in my Guild was on how to maintain a watchmaker's lathe, and they're similar enough. Once you get it torn down, you'll see that the guide pins in these things are made to be replaced. I don't remember if mine knocked out of the inner spindle with a drift punch or if I had to drill it out, but it wasn't that big a deal.

Once the pin is out, check the inner surface of the spindle and make sure things are smooth. The spindle is hardened; it shouldn't have been scarred by the pin, but you need to make sure there aren't any galled bits of pin stuck to the inner surface. If there's anything in there a gentle touch with a file should take care of it. The inner surface of the spindle isn't a critical surface, but still...

Once the pin is out, if you slide a collet into the spindle and align the slot with the newly-revealed hole you can get an idea of how long the new pin needs to be. You don't want the pin to bottom out in the collet's slot; there needs to be a bit of freedom. Make a new pin out of mild steel to be a good friction fit in the hole and drive/press it in place. These pins are intended to shear, so don't use anything other than mild steel. If you're not confident with what "friction fit" means (or if you just want to save time) Loctite 680 on a that's-a-nice-snug-fit new pin will ensure a bulletproof installation. 680 is for not-threaded applications. If you use it the pin doesn't have to be the exactly-right size and you don't have to hammer on the spindle as much. It has become a good friend in my machine shop.

File/sand the pin down to blend it seamlessly with the outer surface of the spindle. Double-check that a collet doesn't bind. Be prepared to do some creative file work inside the spindle without scarring the inner surface. (Ask me how I know this, too. Sometimes it takes a while to learn, you know?) While you have the headstock torn down you may as well do a full overhaul on it. You'll learn a LOT about the lathe and how it works, and it'll give you a great deal of confidence for the future.

Then don't do that again, knucklehead. (That's what I say to myself, so you get to share. )

Smile. With what you've shown in making that tool this should be a cakewalk. Mostly.

Good luck.

Glen

 

[gmorse]

Hi Jeff,

Thanks for sharing this cautionary tale, a good many people would have kept quiet about it, so well done for being open and honest about this. It may be possible to salvage the lathe with some spare parts or the help of a good machinist, of which there are many here.

Regards,

Graham

 

[wefalck]

I hope, it's just the locking pin, that's easy enough to repair as Glen explained. However, it looks, as if there are more bits of metal stuck in the groove for the pin - or is this just some smeared over debris from the pin ?

These pins often get marred or distorted by tightening the collets too much or if there are accidents with chucks or collets. Such 'events' not only mar the pins, but this can also raise the edges of the grooves, slighly increasing the diameter of the shaft. You can file them round again or use a fine abrasive wheel in a hand-held drill to deburr the edges of the groove. That is the main cause of collets binding, when you insert them. Easy to repair, as not mechanically relevant.

 

[Jerry Kieffer]

Thank you all for the replies.

So...you want the good news or bad news first? Actually, there is no good news, except for the fact that I finished the tool I was working on and learned a painful (and expensive) lesson. I relate it here in the hope that it may help prevent someone in the future from doing what I did.

I'm a novice watch repairer, with about two years of experience. I am self taught. I've read (and understood) Fried, de Carle, the Chicago School of Watchmaking, as well as Perkins (The Modern Watchmaker's Lathe), along with many other treatises on watchmaking. Somewhere in those pages was something to the effect, "when undertaking a new procedure, THINK before you act". That thinking should have started when the face plate (and the wire chucks before) were not going in easily. But now we move from that first warning to my present calamity. I hate to even say it, because it is so embarrassing and obvious now "after the fact".

I got out my trusty vise grips and wrapped some rag around the "post" and with that secured in place, I put a length of hardwood between the clamps of the face plate. (you see where this is going)

Using some rather simply physics, I gently began to use my lever. Eureka! It works! A bit stiff, mind you, but it works. Strange how it didn't just "release" and let me screw it off the rest of the way. Yes Jeff, you genius, that's because you clamped down your vise grips on the back end of the front housing bearing instead of the bit of metal to the left that is part of the draw bar (draw-in spindle). By doing that you locked the front bearing in place and the chuck key along with it. Then by using your lever to turn the face plate, you got it unscrewed, but you also sheared off the chuck key at the same time.

You ever get that sort of sick feeling in your gut when you break (ruin) something? I've already had that since this all started a couple of days ago. Well, now you can multiply that a few times, and that's what I feel now. Sick, sick, sick. I might be able to salvage the face plate with some work, but I've ruined the lathe. The drawbar is securely stuck inside the bearing (no doubt there was distortion to the back end of the bearing from using the vise grips). It's just a train wreck and now I have no lathe. Absolutely sickening. But there it is in all it's gory detail.

So what was I working on when this all happened? I've been working on a Waltham model 1894 Riverside pocket watch and needed to do some hairspring work. I had just finished making a tool in de Carle's "Practical Watch Adjusting" (pgs. 45-46) for use on hairspring pinning/ adjustment. I used the face plate so I could make final adjustments to the brass disc I had made. I've included a photo of my finished tool.

Small comfort for the loss (destruction) of my lathe.

View attachment 633572 View attachment 633573 View attachment 633574

Jeff

Glen and Wefalck covered inspection and repair corrections if required.

However there is one consideration to consider.

Years ago when I used a Watchmakers Lathe, I was never able to find a practical purpose for the pin in the spindle. While I understand having a pin for indexing a collet and preventing collet rotation in the spindle, in real life use, neither are required and in the end actually proved to be a hindrance.
The pins are rarely tight enough for indexing and the resistance to rotation of a closed collet is far greater than the poor transmission of a typical watchmakers lathe.

One day while cleaning a Lathe with the spindle removed, the pin came out and I never bothered replacing it. This in turn actually improved the accuracy of the Lathe in some cases. Another words when I wished to mount a work piece requiring a high degree of accuracy in a collet, I was now able to rotate the work piece in the collet as well as rotate the collet in the spindle in various locations. Again in turn, this often resulted in a higher degree of mounting accuracy in less time.

I suspect you would experience the same result.

Jerry Kieffer

 

[wefalck]

Jerry has a point. I have a Wolf, Jahn & Co. milling machine that takes the same 8 mm collets and when I got it, I discovered that the pin was missing. Thinking, that the absence of the pin might provide me with some safety, should say a fly-cutter become stuck, I left it off. This was some 15 years ago and I never had any problems with the collet slipping. Indeed, it is normally the round belt that slips first anyway.

On the other hand, manufacturers must have had a reason for retaining the pins in their designs until today. Perhaps, because there is a discrete risk that a slipping arbor from a chuck, which is normally also hardened, can damage the spindle cone.

 

[DeweyC]

WR Smith promoted the practice of removing the spindle key which is generally discredited. The fact of the matter is the key is important for ensuring the consistent location of the collets and chucks. The collets are bored and the chuck arbors turned using this keyway to locate them during manufacture.

While removal of the key may provide sufficient precision for clocks (WR Smith's area), watchmakers seeking precision and accuracy (these are two different concepts) who actually work to microns have enough problems without introducing errors of their own making.

In all the books on ww lathe use (Perkins, Jendritski, even Goodrich) I never saw this practice promoted. Ya pays your money and takes your choice.

 

[wefalck]

You are right in prinziple, but this would apply, if the bores of collets and the locating surfaces of chuck arbors and the jaws of the chuck were ground to the spindle in which they are used. Arbors are ground between centres and collets and chucks in spindles - they will be accurate with respect to thoses spindles, but the precision in use depends on the cumulated imprecisions of the set-ups in which they are ground and the imprecision of the spindle in which they are used.

I am not advocating the removal of the key-pin, but noted that there is sufficient friction between the collet/arbor and the spindle in practice.

 

[DeweyC]

Perhaps the European method differed from that in the US. Look at Schaublin lathe production (made to master) vs. Levin (bored as matched set).

When I make an arbor for something, I include a witness on the arbor that aligns with the slot opposite the stamping to ensure it is as close as possible when next inserted for use.

 

[wefalck]

In the old days the German manufacturers (e.g. Boley, Lorch&Schmidt, Wolf&Jahn) asked the headstock or the whole lathe to be sent back to them for matching certain parts purchased at later date, namely tailstocks, by grinding them to the existing parts. I am not aware that this was practice for spindle tooling, partcularly collets. Collets manufacture seems to have been outsourced to specialised companies (e.g. Ortlieb, who still trade).

I agree, that it is good practice to mark shop-made arbors to ensure a repeatable set-up.

Normally, when you have lathe with the key-pin intact, you are 'locked' with the given orientation of a collet or chuck. With no key, you could, as Jerry suggested, to choose an orientation that gives you a minimum run-out and put a mark onto the collet or arbor that corresponds to a mark on the spindle-nose.

 

[DeweyC]

With no key, you could, as Jerry suggested, to choose an orientation that gives you a minimum run-out and put a mark onto the collet or arbor that corresponds to a mark on the spindle-nose.

That may be one way. The way I was taught in machining courses (AWI and Wostep) was to simply rotate the work in the collet. Nothing is gained in this regard by removing the key. I keep everything as original and adjust the work. Otherwise, compound faults are introduced that have to be untangled.

In quality products, whether watches or machines, I am not inclined to think I know better than the maker. I have seen far too many Chelsea ship strike racks filed into uselessness because someone thought they knew more than Chelsea.

 

[Jerry Kieffer]

You are right in prinziple, but this would apply, if the bores of collets and the locating surfaces of chuck arbors and the jaws of the chuck were ground to the spindle in which they are used. Arbors are ground between centres and collets and chucks in spindles - they will be accurate with respect to thoses spindles, but the precision in use depends on the cumulated imprecisions of the set-ups in which they are ground and the imprecision of the spindle in which they are used.

I am not advocating the removal of the key-pin, but noted that there is sufficient friction between the collet/arbor and the spindle in practice.

Welfalck`s explanation is in line with what is usually explained if manufactures are contacted .

When dealing with issues such as this, your most accurate information will come directly from the manufacturer of the product discussed, rather than those not involved in the processes.
If you were to contact the manufactures listed, you will likely find that their collets are utilized in many machines and fixtures other than Watchmakers Lathes and always have been. As such, the slot in the collet is placed there to prevent rotation in use under load and to index a collet in a fixture such as square and hex collets as one basic example. However, none that I have contacted including the ones listed, utilized the slot for the production process of the collets as they explained it.

In addition, When contacting lathe manufactures, you will find that each has their own bearing, spindle and collet runout specifications and of course they will be very minor but still exist. Again as such, the ability to rotate the collet in the spindle will allow you to often find a sweet spot where one runout can offset another. While this type of accuracy is seldom required in Horology, it is required in some micro machining in industry.
I occasionally do micro machine training for industry as well as trade shows. This type of thing is demonstrated as part of basic setups and easily observed by those experienced in micro machining. For Horological purposes, I last publicly demonstrated it at the Milwaukee national NAWCC meeting.

While lathes and Mills utilizing rotating bearings, spindles and collets are of sufficient accuracy for the most accurate Horology requirements, they are not accurate enough for many applications in industry. In todays world most micro work is done with various technology's but some applications still require the use of drills and machining tools for desired surface finishes.

I mention this since we are discussing runout and the only machine tool maker I am aware of that claims "Zero" tool runout, is National Jet and their 7A drilling machine. Specs per first photo. Note the zero runout and smallest drill to .0001" or .0025mm if my math is correct.

Home

Our Services Micro Hole Drilling Micro EDM Wire EDM Swiss Machining Inspection Repair National Jet Company is a full service precision machine shop that specializes in micro

www.najet.com

When I occasionally demonstrate this machine, I sometimes drill a hole in a piece of hair and insert a piece of .001" EDM wire in the hole as a handout. The hair is suspended across a small watch movement for size reference for those who take photos.

Second photo shows the machine overall. Depth control is per the red arrow and is .00004" per graduation.

Third photo is of the hair setup last used with the actual drill diameter to small to be seen

In this case the drill has Diamond "V" bearings and the drill or mill is mounted on the spindle and then ground at the factory an a diamond "V" fixture.
The tool is permanently mounted on the spindle and the spindle is changed each time a tool is changed. When a tool needs, replacement the spindle is returned to the factory and a new tool is ground on it.

fourth photo shows the spindle per red arrow. Blue arrows show removable drive pulleys and the green arrow the collet tensioner.

Fifth photo shows the machines diamond spindle pockets

Sixth photo shows the .0008" drill used to drill the hair compared to a .3mm ball point pen ball.

Jerry Kieffer

 

[DocOpera]

I really appreciate all the input! I disassembled everything last night. And, yes, there were bits of metal from the sheared off chuck key. Some bits of metal had made their way down to the draw bar, and I believe that was what cause it to stick. It took careful, but considerable effort to get the draw bar out. There was some damage toward the back end, but I think I can stone that smooth again. In the process of getting the draw bar out, the front house bearing (not the one that slides out, but the friction tight one that is the main front housing bearing) also came out. But it gives me a chance to really inspect and clean everything. I've read it can be a bit tricky getting that back in place due to the oil holes needing to be lined up as well as the exact position of the bearing in the housing. So I've got some work ahead of me. But I am more than willing to give it a go! Assuming I can get it back together and running, I will definitely try it before deciding whether or not to replace the chuck key.