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Seikosha movement - strange beat per hour

hokavan

By hokavan
in Watch Repairs Help & Advice

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hokavan Watch Enthusiast

hokavan

Posted
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Hi all

I'm servicing a Seikosha movement 17 jewels with caliber no. is 297 (I guess).

It is a movement of vintage Seiko Champion watch. I have cleaned parts by ultrasonic; lubricated it. 

For the balance wheel shock assembly, I pegged the cap jewels (top and bottom), lubricated it with 9010 oil. After installing the balance wheel, it tick and tock. The upper and lower pivot of the BW is in the house of the shock assemblies. I also demagnitized the BW

The problem is: the beat per hour is 21600 but as far as I know it should be 18000 (see photo). And  it varies with different positions (see in the video). The rate is very bad with several hundreds seconds offset. 

So now I really need your help to fix this problem. 

The BW pivot is in the top shock assembly

 

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jdm Distinguished Member

jdm

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Is not a matter of beat rate but simply the signal is all over the place, the instrument can't pick a steady refernce.

As in all the many similar discussions here(and many related to Seiko) the issue is 99% with the escapement. You may have cleaned pegged an lubed  but that doesn't prevent a bent pivot, tight end shake, faulty pallet, distorted hairspring and I might name a 10 possible more possible reasons.

You have to inspect, try, possible replace something and try again. Good luck.,

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rogart63 Distinguished Member

rogart63

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One thing that strikes me is. In the first video it's very noisy . Are you sure the TG isn't picking up the noice from outside and inside the room .  

And check the hairspring as they have tendency to rub on the balance bridge. Must be perfectly flat. 

 

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Nucejoe Distinguished Member

Nucejoe

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2 hours ago, hokavan said:

Exactly. I'm looking for replacement on the bay...

If the pallets are undamged and only dislocated ,"moved in the fork slot" they can be adjusted. Our knowledgable guest  @nickelsilver  did help a member fix such fault, you can find the post among his work. There is also a video put out by ETA showing the proceedures. I personally do a good job of messing up adjusting pallets.

Best Regards joe

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hokavan Watch Enthusiast

hokavan

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On 8/1/2019 at 10:05 PM, Nucejoe said:

Looks like pallets jewels have moved.

 

Hi all,

I found and bought another movement and replaced pallet, lower shock absorb jewel, lubricated then adjust the rate. Now the watch keeps about 38 hours will fully wound, rate is about 10-20 sec/day. I think its is acceptable for a nearly 60 years old movement. 

Thank you for your advice.

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