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KneeDragger

Asian ETA problem.

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Hello Gents. I have a Sub I got from Andrew at TT a year or so back. It's got a high beat ETA clone that's been running well up to a few weeks ago. It randomly stopped running so I started poking around and saw that the balance wheel had jumped the pallet fork. The impulse jewel was striking the outside of the pallet fork essentially locking the movement up. I reset the balance assembly and got it to run again but now this a continuous occurrence. Should I buy a new balance assy? Could the catch on the pallet be worn? I've never ran into this problem. 

Edited by KneeDragger

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A fairly common problem with clone movements, and as this has only just occurred it sounds like wear. Obviously the problem lies with "end float" in either the staff or pallet fork. Knowing which position, ie dial up or down this occurs may point you in the right direction to find the culprit

 

Firstly I would check for wear on the fork pinions, as these are not normally lubricated, they are one of the first things to wear and on Asian movements the pinion material is very soft. Check by delicately lifting the fork at the horn end to see how much play you have. If the fork pinions are worn a new pallet fork would sort this out.

 

Don't forget that the wear on the fork pinion could be either vertical or lateral, so it could be that the pinion in the jewel fit is good but the friction shoulder(s) on the pinion could be worn

 

There has been a few rare occasions where the fork pinion jewel in the mainplate has moved in its mount,  so take a look at that also. An indicator of this is the position of the pallet jewels, they should strike the escape wheel on their centre line. I have to admit on Asians this is rarely the case

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Thanks for the tips! I ordered a gen ETA pallet and balance assy. The pallet came in Friday and its been running like a charm since install. I also gained a bunch of amplitude as well. It usually ran around 170-180 degrees but now its around 220. Could improper lube on the pallet have caused this? Ill probably put the gen balance assy in as well when it arrives to try and reduce the beat error.

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If it's running at 220 your way to low on amps, you need to be 275-315 for decent time keeping and a healthy movement. What is your beat error dial up showing?

 

If you've ordered a balance complete (part 721) the you will have to attach this to the [censored], that is unless you have bought a complete balance and [censored], if so then it will be chinese and to be fair won't be the best it can be.

 

you should be looking to replace the mainspring to get your amps up, this is almost always done on servicing. Also check the internal walls of the barrel for wear.  Saying that, you should first check the movement, clean it, especially the Jewel holes and don't wear a jumper when you do it, you'll fill it full of fibres you've been working hard to clean out !! Lube as eta, don't oil the pallet pinion jewels and at this point don't oil the pallets themselves

 

Incorrect lube on on the pallets could have caused it, but in your case I suspect the pallet pinions or indeed the pallet settings themselves were at fault. 

 

Before you you attempt to time this piece in check dial up and dial down readings, if they're not within a max of around 6 secs you won't be able to time it in accurately

 

Everything in the watch has to be correct to get both good amplitude and isochronism

 

Its a a bit like baking a cake, every ingredient has to be in there to get tasty cake

 

Hope this helps

 

 

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Beat error bounces from .6 to 1.7ms with about -15 to +25 s/d, dial up and down respectively. I found a guy selling a complete balance wheel and bridge assembly on eBay from an ETA that he had listed for parts. 

 

Once that that shows up I'll do a more in depth cleaning. Thanks a bunch for the help. ?

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I think your watch is either magnetised or the hairspring is clashing/sticking. Your beat error should be static, I'm pretty sure the new balance will sort the beat error out.

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Its been a while. I forgot to update as i went along. New generic balance wheel installed, and still low amps. I removed and cleaned the gear train, and installed a new main spring. It still runs with low amperage and a beat error of about 1.4-2.0 ms. The rate also fluctuates all over the place. It will be -14, bounce to +40, down to +6, back to +30. I'm getting ready to throw in the towel and just buy a Gen ETA.

 

Help.

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I'm intrigued, fire it over to me and I'll do a freebie for you

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Thanks for the offer. I have a degausser ordered that should be here tomorrow. I'm going to see if its slightly magnitized and maybe that will help. If not i may take you up on that.

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