Freshly serviced pin pallet movement runs slow

[Chopin]

I have a swiss pin pallet movement (the EB kind) that I had to disassemble a few times (don't ask...) and now it seems to run slow by a few minutes per hour. It used to work fine. I actually serviced it twice and it seems to do the same thing...

Technically speaking, what part/parts should be responsible for this ? Is it the hairspring by any chance ?

Edited November 14, 2017 by Chopin

[noirrac1j]

It could be the hairspring, but usually that results in running fast.  Which Bettlach is it What about the mainspring? Did you take it out and clean/grease it? 

J

[Chopin]

I didn't clean the inside of the mainspring as I don't have the tools to put it back together but it worked fine 2 disassemblies ago. I did grease the areas where there's supposed to be grease.

[noirrac1j]

I didn't clean the inside of the mainspring as I don't have the tools to put it back together but it worked fine 2 disassemblies ago. I did grease the areas where there's supposed to be grease.

Ok. Its hard to say what could cause it to slow down, but something along the drivetrain path is likely cause. Do you have a timegrapher to check amplitude?

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[Chopin]

Unfortunately no. I have to just wait and see whether it's fine or not... There are some apps for Android but I can't get any to work at the moment and my phone is crap.

[noirrac1j]

That is true.  What caliber is it?

J

[Chopin]

I don't remember exactly I just know it's an EB. From the 60s or so.

I fiddled around a bit with a pair of tweezers and the small wheels/cogs and now it works fine... The wheels stay in place just fine so what exactly could have cause this ?

[noirrac1j]

4 hours ago, Chopin said:

I don't remember exactly I just know it's an EB. From the 60s or so.

I fiddled around a bit with a pair of tweezers and the small wheels/cogs and now it works fine... The wheels stay in place just fine so what exactly could have cause this ?

Its really a process of  elimination with these, but in my experience there are a few things to inspect carefully:

1) Fouling of the hairspring with oil/dirt (usually will run fast) or even a small fiber (runs erratically or stops intermittently).

2) Bent pivot on one of the gears, or plate drilling that has worn and pivot is wiggling around when running.

3) A bent or dirty pin on the lever itself.

 

Everything else being OK, these will usually be the areas I inspect when a pin pallet doesn't run well after a service. These areas are best inspected before reassembly so that repeated teardown/reassembly isn't required--been there!

J

 

[Chopin]

No damage of any kind as far as I can see... Sometimes watches are strange...