Is this pallet fork over-locking?

[margolisd]

I’m troubleshooting a Seiko 6601a which has poor amplitude. Around 180. Does anyone agree the pallets look a tad overlocked?

[HSL]

Just looking at the pictures your analyses are spot on, at a closer look the entry and exit seems to also differ in depth these should also be equal in depth.
If their not you get exactly as you say loss in amplitude.

[margolisd]

Thanks HSL. I think it’s time to warm up my pallet stone adjustment tool! 

[HSL]

Now I tried to "adjust" them for you it should be something like this.
Almost the whole "chamfered" part of the club is locking the pallet at an equal depth at both entry and exit pallet.

.
The pictures are not good but I have made some cad drawings once upon a time from them you can get a feeling of how it should look like.

[margolisd]

That’s cool. Did you adjust in photoshop? That’s a great reference. Thanks.

[HSL]

No Corel CAD 2019, nice when you want to do something quick and dirty, think this example was something on how to design escapements from a BHI course.
 

[margolisd]

That’s great. I’ve been using Shapr3D. Which is an iPad app. It’s absolutely great to quickly “sketch” something. I use it before I jump on the lathe so I can quickly visualise to scale what I’m going to do.

[margolisd]

The plot thickens. The upper escape wheel jewel hole is badly worn. Way too much side shake. So my theory is that the escape wheel is leaning in to the pallets messing up the geometry. So I might change the jewel before I move the stones.

Edited September 16, 2020 by margolisd

[HSL]

Think that is a great start. One easily forgett to check jewels and pivots. And you shouldn't do anything to the pallet jewels until fixing the jewel.

 

6 minutes ago, margolisd said:

That’s great. I’ve been using Shapr3D. Which is an iPad app. It’s absolutely great to quickly “sketch” something. I use it before I jump on the lathe so I can quickly visualise to scale what I’m going to do.

That is just what I to do nowdays, technology sure makes it easier some times but then it comes down to the fingertips in the realization..

[nickelsilver]

Don't forget to do all the escapement checks before you start moving stones. Drop lock, run to banking, fork horn clearance, guard pin clearance.

[rodabod]

I’ll just add that it’s sometimes hard to judge from photos, and that the depth of lock didn’t actually look necessarily too deep to me. 
 

From my experience with some older Seikos, they are sometimes a pig to get decent amplitude from, and I put this partly down to premature wear of the bearings (pivots or bushings). I tend to avoid them for this reason. But I don’t want to put other people off! 

[JohnR725]

56 minutes ago, rodabod said:

I’ll just add that it’s sometimes hard to judge from photos, and that the depth of lock didn’t actually look necessarily too deep to me. 
 

From my experience with some older Seikos, they are sometimes a pig to get decent amplitude from, and I put this partly down to premature wear of the bearings (pivots or bushings). I tend to avoid them for this reason. But I don’t want to put other people off! 

 

3 hours ago, nickelsilver said:

Don't forget to do all the escapement checks before you start moving stones. Drop lock, run to banking, fork horn clearance, guard pin clearance

 

3 hours ago, margolisd said:

he plot thickens. The upper escape wheel jewel hole is badly worn. Way too much side shake. So my theory is that the escape wheel is leaning in to the pallets messing up the geometry. So I might change the jewel before I move the stones.

this is a modern mass-produced watch the likelihood of the depths of the stones not locking correctly is almost nonexistent. If somebody  played with it and change them  yes they could be wrong. This is where it's really important to check everything else because there is probably something else.

There actually are rules on how deep locking should be but they're also dependent upon doing the escapement checks because they also control how deep the locking should be.

Then have ever heard a story about it Seiko that had super amplitude? The answer is no because it was never designed to run with a lot of amplitude they always have pathetic amplitude because that's the way they were designed. They even put oil on the pallet fork pivots one of those things you never supposed to do that kills amplitude yet they do it why? because for reasons that we have no idea they were designed to run with pathetic amplitude. That doesn't mean you can't tweak things like you can improve the regulation we could probably improve the amplitude but they weren't designed that way from the factory.

And 99.9% of the Seiko service manuals they never reference the amplitude except in one particular manual that is mentioned. 4006 a and I have it snipped out for you.

[HSL]

Interesting reading, my rambling will not be long, as I think @margolisd is a bright man who has ambitions to learn and take his knowledge to the next level and therefore asks for advice from a diverse group like this. I don’t see any problems in people wanting to learn and experiment a bit maybe he could tweak it to an amplitude above the normal.

I couldn’t agree more the most mass-produced watches leaves the factory with “good enough” specs standard Seiko’s is no exception, maybe more the norm, that is it keeps time within the given specifications and nothing more. It’s the same as with any mass produced product I would say.
Then there are products that gets tuned a bit above the normal specifications, these products are given a little more attention. Mostly they put in parts with a higher-grade material and finish in the escapement and balance system. Sometimes they even are adjusted in the matter of getting the perfect position on the jewels in the pallet fork in regard to length and height position. Sometimes even the pallet jewels are off by a hair, but works satisfying according to the specification, but one rectifies this error anyway. And so, it goes on.  I guess this is the tuning procedure margolisd is examining. I think too many nowdays is satisfied to just service the watch into just good enough condition. 

Just to see if there were some different thoughts of this philosophy regarding the entry and exit pallets I took a small trip to one of my favourite websites this morning eager to gain new knowledge about this matter.

https://www.awci.com/watchmaking-excellen/drop-lock/

I guess the theory about the pallet jewels position seems to be the same here, which actually was margolisd initial question. There seems to be a drop lock issue.
But after a closer examination he found some plausible problems that would explain this possible issue with the pallet depth, hence why one should always do the  checks suggested by @nickelsilver before and after an effort to rectify the problem.

[rodabod]

John makes some very good points. Especially the “mass produced” bit. 
 

The only thing which I find far, far more common than incorrectly set pallet stones (or swapped lever with incorrect pallet depths) is misadjusted banking pins. This obviously only applies to those which can be adjusted. 

[JohnR725]

16 minutes ago, rodabod said:

misadjusted banking pins. This obviously only applies to those which can be adjusted. 

In watch repair if it's movable it definitely should be moved. Banking pins are perfect example of that common in American pocket watches you have to check them every single time because somebody probably has moved them without a clue of what they're doing. But do not feel safe just because those banking pins are not movable there is a tool in case you feel they should be moved.

[nickelsilver]

With all due respect, what is your training Mr. Margolis? I ask because I've encountered a number of school graduates both Swiss and otherwise, who were fairly clueless about adjusting escapements. I think in part due to what John has said above, and just a lack in the training. It's a really important thing, WOSTEP used to spend weeks on it in their fabled but no longer "Refresher Course" which was really just a mindf@ck of adjusting escapements and hairsprings for 20 weeks. Sorely missed now. I really want to put together a crash course for here, but time is the limit. Just did a ruby passing cylinder 4 tooth escape wheel duplex watch, remaking the missing oddball stopwork ring. Got two marine chronometers needing repivotiong and one a detent too. It keeps pouring in.

The good info that used to be easily found is disappearing- but the above linked AWCI stuff reveals a _lot_ of escapement info if you dig in. I will put something together in the next few months. I'd say I adjust the bankings or stones on 25%- 35% of what comes through. Much is 70+ year old stuff from a major manufacturer, and often those have solid bankings machined into the mainplate and stones cut so they bottom out on the fork slot- what a joy!

[rodabod]

My experience with other students is that often they are not interested in theory. Not all, but many. I think it is literally a dying art, sadly. I tend to find that the clockmakers that I train alongside have a greater interest in the theory side. I suppose you really have to with clocks if you are making parts and adjustments regularly. 
 

Fortunately, we will always have the fantastic books which have been written that cover horological theory in great depth, so it’s there if people want it.