Another bound-up train…

[tmac1956]

All:

I have run into yet another pivot/escape wheel combination that is just locked up. The pivot fork jewels have been replaced in the past. Can you see anything between the two that looks wrong? The photos show the interface between pallet fork and escape wheel when the fork is against the banking pins – left and right. Sorry about the blurry pics.

Thanks!
Tom

[willofiam]

Tom, not sure what you mean by “locked up” but is there power to the escape wheel? looks to me the banking pins are too far in. do you have it partially disassembled? I like to look at the escapement under a bit of power with everything in place except the balance assembly. William

[tmac1956]

William:

I don’t have the mainspring barrel in but with the other four gears in place, the train spins freely until I put the pallet fork in. With the fork in, you have to giggle the train to get it to spin and then it’ll spin for a second and then lock (won’t move). I thought about moving the banking pins out a little to see if that would help. It could also be too much end shake on the pallet fork pivot – or both.

I put in the mainspring barrel and I had to push it down to get it seated. The mainspring arbor is too large for the hole that it sits in, so I’ll either have to ream out the hole or turn down the arbor shaft.

I had to replace the balance staff, so I’ll probably have issues with that too. These ebay pieces always have issues. Anyway… these are just problems to be solved I suppose.

Thanks!
Tom

[tmac1956]

William:

I opened the banking pins slightly an oiled the escape wheel contact points. She spins good now.

Thanks!
Tom

[bobpat]

@tmac1956 wrote:

William:
you can say that again Tom 🙄

These ebay pieces always have issues. Anyway… these are just problems to be solved I suppose.

Thanks!
Tom

[bobpat]

Tom, Did you change any of those Jewels. They look new or very clean. and Nice pics. Did you try the camera and Loupe?

[chris mabbott]

Tom my American brother, you got yourself one a dem there “last train to skaville” pieces

Someone has accidentally or purposefully, fiddled with the banking adjustment screws, or replaced the pallet stones not quite accurately..

There’s a mathematical equation somewhere, that allows you to set up the pallet stones/banking action correctly. I don’t have it handy but I’m certain that Mr. Pierce or someone may be able to provide it.

As you know, incorrect setup of the BPs can result in the release of all kinda of gremlins, including Cornish pixies
In the form of lock ups, broken pallet stones, even broken escape teeth, on the extreme side.

The setup method is probably in one of the books you have.

These lockups seem to be common on Illinois/burlingtons/Hampdens that I’ve had in the past, not sure why, no fault of these makers ..

[tmac1956]

@bobpat wrote:

Tom, Did you change any of those Jewels. They look new or very clean. and Nice pics. Did you try the camera and Loupe?

Bobpat:

On the watch the jewels happened to be in good shape so I just cleaned everything up using the manual method. I did steal your “loupe” trick with the camera – it works well. However, I was having problems holding the camera still while trying to hold both the camera and the piece up to the light just right; hence, the blurry pictures.
Thanks!
Tom

[tmac1956]

@Chris Mabbott wrote:

Tom my American brother, you got yourself one a dem there “last train to skaville” pieces

Someone has accidentally or purposefully, fiddled with the banking adjustment screws, or replaced the pallet stones not quite accurately..

There’s a mathematical equation somewhere, that allows you to set up the pallet stones/banking action correctly. I don’t have it handy but I’m certain that Mr. Pierce or someone may be able to provide it.

As you know, incorrect setup of the BPs can result in the release of all kinda of gremlins, including Cornish pixies
In the form of lock ups, broken pallet stones, even broken escape teeth, on the extreme side.

The setup method is probably in one of the books you have.

These lockups seem to be common on Illinois/burlingtons/Hampdens that I’ve had in the past, not sure why, no fault of these makers ..

Chris:

I’ve got the formulas and I’ve gone though them enough that I understand the geometry (I think). My problem is getting enough magnification and lighting under the plates/cocks to be able see the dimensions between the pallet stones and escape teeth and/or the pallet fork slot with the roller jewel and banking pins . I’ve believe that David once told me that to do this job correctly one really needs an optical comparator, otherwise you just have to fiddle with them tinkering them into adjustment. That’s pretty much been my approach and its one that I don’t really like.

I’m the type of person who needs to be able to come at a problem with a solution that is repeatable, so fiddling and tinkering with things then eventually falling butt first into a solution drives me nuts – especially when there are often multiple problems all contributing to the same error. To me it’s like trying to put a piece of carpet cut two inches too short down into a room. When you tack one side down and then stretch the other side to fit, one corner of the first side pops up and off you go chasing your tail never getting the carpet job completed. I know sometimes that’s the only way – it’s just the OCD programmer in me I suppose.

Thanks my friend,
Tom

[chris mabbott]

I’m feelin ya buddy, it’s definitely a bee-atch of a job on full plate models, although I’m not sure how the optical comparator would work while its installed? But I would like to see it demonstrated to satisfy my own curiousity. Mind you, that would probably cause me to visit William and try to talk him out of his

I’ve tried checking with the top plate removed but everything just wobbles around too much to attain any accuracy.
I’ll have to put my thinking cap on and try to make some sort of test jig specifically for full plate models. The other option left to us is…..we simply dont buy watches with this problem haha

How are you checking the clearances between balance jewels to determine the correct fit of staff/jewel depth?
I’ve yet to find a method other than the “old end shake” test, which one full platers is also a pain in the tush..

[tmac1956]

Chris:

I’ve had luck in the past measuring the distance between the top cap jewel bezel/plate and bottom jewel plate, then subtracting the two plate thicknesses to get the balance staff length pivot to pivot dimension. Then measure the actual balance staff length and compare the two. The pivot tips should be bearing on the cap plate inner surfaces but the dimension shouldn’t bet too tight, otherwise it wears the pivot or the jewel. The next question I have is how tight is too tight? How many thousandths… Perhaps David or Bob can give that dimension to us.

I’ve seen this detailed in several books, but the one that I could put my hands on the fastest is Fried’s “The Watch Repairer’s Manual”, page 127, Fig. 2.

The jig sounds like a good idea and David actually mentioned that to me before. I could use two pieces of thin brass plate, mark off the measurements for the pivot holes, and drill them out. I’d have to build a little piece for the pallet fork cock and mill a spacer to separate the top and bottom plate, perhaps holding them together with some old plate screws. While I’m at it, I guess it would be prudent to build in something to hold the balance assembly too. Pheeww… that’s a lot of work but it’s probably the only way to see the interface between escape wheel/pallet fork/balance assembly.

Based upon my success rate at finding decent movements, it looks like I’ll be building a jig for just about every piece I work on. As you said, there’s really no telling who has done what to these things.

Bob… I need an emoticon for whining please. :ugeek:

Thanks Chris!
Tom

Oh.. The is a 16s Elgin that isn’t one of the old single plate models.

[tmac1956]

All:

I think the last person to put in these pallet stones wanted to make sure that they didn’t come out.

I took this with my Amscope camera. I’m going to these parts back into the plate and use backlighting to try to see the interface between the escape wheel and the pallet stones with the pallet fork against each banking pin. Perhaps that will reveal a problem.

Thanks!
Tom

[tmac1956]

All:

These images were taken again using the AmScope camera (inside plate up). The first two were taken with pallet fork on the left banking pin, the last two with the pallet fork on the opposite banking pin.

Based upon what I see in my reference material it appears that the pallet stones might be a little short. This level of magnification certainly reveals how dirty these parts really are. I’ll have to take a brush to them again. I’m going to learn how to do this if it kills me!

Any thoughts – do I have this totally wrong?
Thanks,
Tom

[arutha]

From my very limited experience I would say that in the top picture the jewel looks like it is protruding too far and in the bottom picture its not protruding enough. I dont envy you this job of adjusting the stones, when I did one of the pallet arbors on a wall clock platform I must have had that fork in and out about 15 times before I got it right 😯
Good luck Tom and keep us updated.

[Bob Tascione]

Tom,
Great close up shots!
In the last pic where no locking occurs, is the banking pin adjusted all the way out to allow full travel of the lever?
Bob

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