Jump watch sticking

[Boogi11]

Hi. I have stripped and rebuilt a jump watch and it appears to work fine however it is getting stuck in the hour movement. The minute hand is a nice tight fit with no slippage and the full movement works fine when adjusted on the crown. However under its own steam it sticks . It’s happening as it jumps from one hour to the other . Any ideas . Should anything on this top side be oiled

 

 

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[noirrac1j]

What is the movement? Does the hour not turn over, but it keeps ticking? If so then problem is mainspring barrel cover/clutch wheel combo....the hour wheel is driven by a gear on the mainspring barrel, which is connected with a slipping coupling--Needs more tension. I'll tell you how to do it, once you confirm.

 

J

[Boogi11]

Hi not sure on movement. It keeps ticking , but hour sticks . Many thanks


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[noirrac1j]

Ah OK its a BFG 582. The problem isn't with the barrel, because this doesn't have a slipping clutch there...its this part:

This  part connects directly with the barrel (you can see the gear just below the part being pointed to). This cannon pinion combination gear should have enough tension that it turns the hour wheel, but enough "give" that it spins when the setting lever is engaged the time. You'll have to remove the dial to check it.

J

[rodabod]

The springs’ “beaks” should be oiled like on any calendar works. D5 should be fine for this. There may also be other moving parts like those found in calendar works which should be oiled with a thick oil.

Assuming it worked ok previously, the spring tension probably does not need to be adjusted. 

[rodabod]

Attached is a photo of a ladies BFG jump hour dial side. I’ve added red dots where it was oiled for the jump hour action. 

[noirrac1j]

Check all of the contact points under the dial.I f the spring is not properly positioned the mainspring will not have enough power to overcome the tension...but that should cause the watch to stop ticking. If the problem is where I think it  is...This movement might be a little different with some parts, but check these areas:

 

J

 

 

 

 

 

 

 

 

 

Edited December 15, 2017 by noirrac1j

[Boogi11]

Check all of the contact points under the dial.I f the spring is not properly positioned the mainspring will not have enough power to overcome the tension...but that should cause the watch to stop ticking. If the problem is where I think it  is...This movement might be a little different with some parts, but check these areas:

 
J
 
 
 
 
 
 
 
 
 

Reply. Cheers. Will do. I may have the hammer spring in the wrong way around . I may try this first


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