Question Regarding Faulty Obsolete Parts...

[DJW]

I acquired a group of antique pocket watch movements and have found a problem with one of them while using my timing machine.

 

It appears that this movement has a faulty escape wheel based on my timing results. Instead of a pair of straight lines that are displayed when the pallet hits both banking pins, the graph shows a evenly spaced "S" pattern...up and down, up and down, etc....

 

This pattern replicates about every 10 seconds. This tells me that the fault probably lies with the escape wheel since it is the wheel that revolves at about this rate.

 

The actual timing over a given time shows a meantime deviation of 0 sec/day but a +15 sec/day, then a -15 sec/day during the "S" cycle.

 

My question is, since parts are likely not readily available and the movement has been running accurately to within 15 sec/day over the first 48 hours of testing, is this a problem that should be fixed or should I accept the fact that the movement runs accurately and not worry about it?

 

The movement is a

Teutonia 19"'

17 jewels

 

 

[DJW]

BTW, the movement does run very strong and has shown no signs of beat error of binding...

[Mark]

Yes, I can confirm that the wavy 'S' shaped pattern is indicative of a faulty escape wheel.

 

Have you checked the pivots are not bent? Also an idea to check for hardened debris in the pivot holes. I have also seen this when there is a little play in the pallet cock so when you place the cock back on the movement the pivot holes do not line up - I needed to keep adjusting it until I got it right. You could also mount the escape wheel in your truing callipers to make sure it is not out of whack.

 

As far as +-15 secs a day, it depends on the owners expectations. If I take on a vintage watch for repair and it is in poor shape I will usually tell the customer that excellent timekeeping may be a stretch and I explain the difference between servicing and overhauling which are two quite different jobs.

 

For example you can get an old classic car and make it run with a service and some tweaks but if you want to make it run like new it's a whole different ball game :D

[DJW]

Yes, I can confirm that the wavy 'S' shaped pattern is indicative of a faulty escape wheel.

 

Have you checked the pivots are not bent? Also an idea to check for hardened debris in the pivot holes. I have also seen this when there is a little play in the pallet cock so when you place the cock back on the movement the pivot holes do not line up - I needed to keep adjusting it until I got it right. You could also mount the escape wheel in your truing callipers to make sure it is not out of whack.

 

I'll check these areas. It was not running when I received it so I'm clueless as to how it ran before. I would like to get it sorted as my intentions are/were to mount it in a case and sell it on.

 

I'll let you know what I find!

 

Don

[Mark]

I'll let you know what I find!

 

That would be interesting.

[DJW]

That would be interesting.

Punt!

 

I cannot figure this out! First, I thought that the pivots on the escape wheel looked really rough...I polished them. Now the watch is all over the place! No more "S" pattern on the timeing machine. but timing was fast, slow, normal.....I sat at my bench until 2am trying to figure this out.

 

After polishing the pivots, the watch would run 30 sec slow for a minute, then speed up, then run 50 sec fast for a couple of minutes. This would cycle every 5 minutes....

So I thought I would check the third wheel. ah ha! Gunk in the pinion gear! Cleaned it all up and inspected everything again and........Nothing! Still running all over the place! Up then down then fine, repeat!

 

Went to bed, cot up this morning and pulled it all apart again! Ah Ha! some dried gunk on the bottom jewel for the third wheel! Pegged it, cleaned it and made it sparkle again! and......nothing! Still all over the place! Mind you, this is after running all the parts through my L&R cleaner, twice!

 

This is probably why I ended up with this movement! It's a shame too, it looks Mint!

[DJW]

I Fixed it!!!! I fixed it!!!! I Fixed it!!!!

 

Anyone care to guess at what was wrong? So simple.......... :lolu:

[Geo]

Punt!

 

I cannot figure this out! First, I thought that the pivots on the escape wheel looked really rough...I polished them. Now the watch is all over the place! No more "S" pattern on the timeing machine. but timing was fast, slow, normal.....I sat at my bench until 2am trying to figure this out.

 

After polishing the pivots, the watch would run 30 sec slow for a minute, then speed up, then run 50 sec fast for a couple of minutes. This would cycle every 5 minutes....

So I thought I would check the third wheel. ah ha! Gunk in the pinion gear! Cleaned it all up and inspected everything again and........Nothing! Still running all over the place! Up then down then fine, repeat!

 

Went to bed, cot up this morning and pulled it all apart again! Ah Ha! some dried gunk on the bottom jewel for the third wheel! Pegged it, cleaned it and made it sparkle again! and......nothing! Still all over the place! Mind you, this is after running all the parts through my L&R cleaner, twice!

 

This is probably why I ended up with this movement! It's a shame too, it looks Mint!

Have you checked the pivots on all the wheels to ensure none are bent? You may have a wheel mating too deeply every rotation. When assembling the watch and before fitting the escapment lever, balance wheel and click try blowing the escapment wheel to drive the train. This should show up any repetitive tight spots that exist and allow you to identify where it goes tight. If all is well it should rotate easily and come to rest at any point.

[Geo]

It obviously wasn't what I thought!

[DJW]

Have you checked the pivots on all the wheels to ensure none are bent? You may have a wheel mating too deeply every rotation. When assembling the watch and before fitting the escapment lever, balance wheel and click try blowing the escapment wheel to drive the train. This should show up any repetitive tight spots that exist and allow you to identify where it goes tight. If all is well it should rotate easily and come to rest at any point.

I did look at all of these things! This is why I was getting so frustrated! But, I did fix it!

Care to guess what was wrong?

[Geo]

Let a few others have a guess then put us out our misery. Well done by the way!

Edited March 18, 2014 by Geo

[DJW]

I'll go ahead and Reveal!

 

 

 

 

"MAGNETIZATION!"

 

 

 

This is were if I had formal training I would have probably been instructed to develop a checklist of set things to go through when trying to diagnose a problem...I bet this would be one of those things that would be on the list!

 

 

Well, it is now!

[Geo]

Interesting, I've had problems with magnetisation before, but it did not manifest in a timed inconsistency. Both times the watches just ran fast.

Question, why did it make the watch go slow and fast at regular intervals?

[Geo]

Oops, replied twice!

Edited March 18, 2014 by Geo

[DJW]

Interesting, I've had problems with magnetisation before, but it did not manifest in a timed inconsistency. Both times the watches just ran fast.

Question, why did it make the watch go slow and fast at regular intervals?

I really have no idea! I wonder if the other problems that I found either accentuated or where magnified by this issue.

 

I sat in my chair last night and watched it on the timing machine run 10 seconds fast, then slowly increase to 60+ seconds fast over the next 2-3 minutes, then slow to -30 seconds for 2 minutes. It did this at 5 minute intervals over 10 minutes. Like I stated earlier, I did find gunk or what looked like white crystalized powder in the leaves of the pinion on the third wheel. I cleaned it completely and it really had no effect of the sporadic timing.

 

I wonder if part of a wheel can become more magnetized than another part...? This would at least give a reason as to why the effects that I saw were so cyclical.

 

Curious!

[Geo]

Curious!

Weard..........Any Ideas Mark?

[Mark]

Ahh well that explains a lot.

 

This shows how important it is to use a de-magnetizer after a cycle through the cleaning machine. It may be to do with the AC motor. I always de-magnetise after re-assembly and before timing.

 

I am sure it is possible to have uneven magnetism on a piece of metal - just lightly magnetise the end of a pair of tweezers and touch a small screw with the end you magnetised - then de-magnetise the screw and touch it with the other end of the tweezers, you will notice a difference.

 

Glad you found the problem Don - well done :D