What is the first thing you check if positional error is high?

[EatPeach]

So I'm dealling with an old ETA 2783 (In case some of you did not fiddle with this particular model, it's basically a 21600 version of 2824) . Normally I can get a 280 amplitude with this model but this time I have a lot of trouble. What I get now is 240~250 and +4s/day Dial Down/Up, 200 -15s/day Crown Down/Up. I've check the endshakes and the hairspring seems fine to me. Anything else should I look for. What's your intuition if you face such problem? Thank you guys!

[Nucejoe]

Have you checked pallet jewels under high magnifiction?  they get scrstched up over time specially if run with dried up oil. 

Fork pivots are not to be oiled.

 

[Nucejoe]

2 minutes ago, Nucejoe said:

Have you checked pallet jewels under high magnifiction?  they get scrstched up over time specially if run with dried up oil. 

Fork pivots are not to be oiled.

 

Your amplitude is lower in all positions, so the impulse you get is not as strong.

[EatPeach]

Your amplitude is lower in all positions, so the impulse you get is not as strong.

so you mean the impulse face might be scratched？Let me check it later. The amplitude is indeed lower than I expected. I took a long time to make the train runs freely but the amplitude is still low. BTW I'm using 9415 and 9010

[Nucejoe]

3 hours ago, EatPeach said:

so you mean the impulse face might be scratched？Let me check it later. The amplitude is indeed lower than I expected. I took a long time to make the train runs freely but the amplitude is still low. BTW I'm using 9415 and 9010

Thats the grease of choice alright. Surely you know considerable amount of energy goes to waste in the escapement. What kind of beat error are you getting? 

 

[EatPeach]

Thats the grease of choice alright. Surely you know considerable amount of energy goes to waste in the escapement. What kind of beat error are you getting? 
 

within 0.5 at all position

[nickelsilver]

If the train is free, balance pivots and hairspring in good condition, and still low amplitude, I check the escapement. First of all absolutely peg the hole jewels for the fork, and clean the fork slot in clean pithwood, make sure the roller jewel is spotless. If all that is in order, you may need to reduce the lock if possible. I actually do on probably 30% or more of the watches I work on.

[EatPeach]

1 minute ago, nickelsilver said:

If the train is free, balance pivots and hairspring in good condition, and still low amplitude, I check the escapement. First of all absolutely peg the hole jewels for the fork, and clean the fork slot in clean pithwood, make sure the roller jewel is spotless. If all that is in order, you may need to reduce the lock if possible. I actually do on probably 30% or more of the watches I work on.

Let me check that. The lock is something I suspect. But I have not pallet warmer to alter the lock, too bad. And I think the stone is really hit the very end of the fork so there's very little I can do with it.

[JohnR725]

You didn't give us the background story did you service this watch? Did you change the mainspring? Then if you did service It what was it doing before you serviced it?

[EatPeach]

You didn't give us the background story did you service this watch? Did you change the mainspring? Then if you did service It what was it doing before you serviced it?

I did service it. The mainspring remains the same as the original. But I guess it's strong enough to power the movement. Before I service it it was a no runner

[EatPeach]

14 hours ago, Nucejoe said:

Have you checked pallet jewels under high magnifiction?  they get scrstched up over time specially if run with dried up oil. 

Fork pivots are not to be oiled.

 

 

There you go

[Jon]

Try checking the amount of play the hairspring has between the curb pin and boot in dial up and down, then check if it's the same in crown up and down. I suspect not. It might be the hairspring is ever so slightly out of true, therefore the hairspring has no movement off the curb pin in that position, or too much. I couldn't tell from your reading if it was gaining or losing in vertical position

[EatPeach]

7 minutes ago, Jon said:

Try checking the amount of play the hairspring has between the curb pin and boot in dial up and down, then check if it's the same in crown up and down. I suspect not. It might be the hairspring is ever so slightly out of true, therefore the hairspring has no movement off the curb pin in that position, or too much. I couldn't tell from your reading if it was gaining or losing in vertical position

losing

[EatPeach]

Jewel holes of the train and pallets. They seems fine to me.

[Nucejoe]

5 hours ago, EatPeach said:

 

There you go

Sorry for my abscence, I lost some graphic aspects of connection to the site plus couldn't post for couple of hours.

I can't see anything wrong with pallets face. perhaps heavy lock on escape teeth, will you show pics before attack , also Jons point for amplitude drop in FU position.  have you checked pivot on cock side?

 

 

[EatPeach]

1 minute ago, Nucejoe said:

Sorry for my abscence, I lost some graphic aspects of connection to the site plus couldn't post for couple of hours.

I can't see anything wrong with pallets face. perhaps heavy lock on escape teeth, will you show pics before attack , also Jons point for amplitude drop in FU position.  have you checked pivot on cock side?

 

 

I've send all pivot holes pics just now. They seems good to me. The update is I found another pallet fork with less lock and change the 9415 with 9010. Now I'm getting 250~260 dial up but 210 crown up

[JohnR725]

Companies like ETA are interesting they have technical information for servicing the watch. But  some of their watches they also had  the manufacturing information sheet.  I've attaching an image from the 2836-2 . A little newer than your watch but it give you an idea about specifications. Notice comes in four separate grades of quality  important to remember when you're doing timing..

What I wanted you notice was  let's compare your hideously bad timing and amplitudes to this? First off the watch companies  almost never worry about  what the amplitude is  except at the end of 24 hours. Then  your horrible  +4 to -15 Timing Variation Really isn't that horrible  if you look at this.. Unless of course this is a chronometer grade watch then you write totally sucks.

 

[rodabod]

The positional variation doesn’t sound unreasonable taking into consideration the slightly low amplitude. 
 

I usually cringe when people immediately suggest checking mainsprings/barrels, but if everything is clean and looks in order, did you check how many barrel turns you were getting before slippage? 

[EatPeach]

1 hour ago, rodabod said:

The positional variation doesn’t sound unreasonable taking into consideration the slightly low amplitude. 
 

I usually cringe when people immediately suggest checking mainsprings/barrels, but if everything is clean and looks in order, did you check how many barrel turns you were getting before slippage? 

No, I did not. But just by turning that mainspring it feels rigid enough for me. At least I think it would be the first priority. Just an intuition

[rodabod]

Yes, the amount of torque you can feel coming back through the crown is usually a good indicator if you have a feel for what is typical, for a given crown size. 

[rodabod]

If you have spares, the I would try experimenting by substituting parts. I have had issues with higher beat-rate ETAs where they have formed a metallic sludge on the escape wheel teeth. 

[EatPeach]

2 minutes ago, rodabod said:

If you have spares, the I would try experimenting by substituting parts. I have had issues with higher beat-rate ETAs where they have formed a metallic sludge on the escape wheel teeth. 

Yes I did change some parts but have no significant improve. I did get some improvement of amplitude by changing the escape wheel and pallets. But the prositional error is still high.

[JohnR725]

25 minutes ago, EatPeach said:

But the prositional error is still high.

As were discussing positional errors  you probably should adopt a better timing policy.. Like time of the watch In six positions.. It really helps for diagnostic purposes To see what it's doing and you can look for actual balance positional error problems. Not that you should have any on a modern balance wheel but she never know.

Reading through the answers above the escapement lubrication did you go minimalistic or heavy on that? The reason I ask is if you have too much of the lubrication it actually causes a decrease in amplitude..

Then the wording of the mainspring remains the same? In other words you using the old mainspring which is fine if did you take it out and clean it?

 

[EatPeach]

1 minute ago, JohnR725 said:

As were discussing positional errors  you probably should adopt a better timing policy.. Like time of the watch In six positions.. It really helps for diagnostic purposes To see what it's doing and you can look for actual balance positional error problems. Not that you should have any on a modern balance wheel but she never know.

Reading through the answers above the escapement lubrication did you go minimalistic or heavy on that? The reason I ask is if you have too much of the lubrication it actually causes a decrease in amplitude..

Then the wording of the mainspring remains the same? In other words you using the old mainspring which is fine if did you take it out and clean it?

 

I think the lubrication should not be a problem. I try different amount and different types of oil. The amplitude is still stuck at 240~260. As for the timekeeping,  any vertical position will lose 10~15s/day so that's a problem. I dont care if the amplitude is low but the timekeeping should be better at least the variance between vertical and parallel should be minimized. As for the MS, it's been clean and oil. It should not be a problem. I'm thinking about the locking, I think it is a little bit too deep but I have no tools to adjust it

[rodabod]

If you’ve swapped all of the escapement components out and still don’t achieve good amplitude then I would start to suspect either a mismatched escapement component, or lack of torque arriving at the end of the wheel train.  It’s a shame there isn’t a more simple way to measure this.... I have been thinking about making some sort of strain gauge, but it would potentially be a lot of work.