Baumgartner 866

[Bonefixer]

I've been working on a jump hour BFG 866 movement. In the original one some parts got broken - teeth on the hour/minute wheel and barrel lid. I think it was too stiff and they broke when time setting. 
 

I got a donor movement and was very careful to lube everything well. It all runs, and winding and setting are as smooth as you like. 
 

The issue is the cannon pinion function. It seems to be built into the barrel lid. It's too loose, such that when it's time to change hour, the force required to overcome the jumper is more than the frictional force on the barrel lid wheels so the watch stops (seconds keep running though). 
 

How do I tighten up the barrel lid cannon pinion, or should I just get a new one?

[JohnR725]

12 minutes ago, Bonefixer said:

should I just get a new one

I think ideally you should just get a new one if you could.

One of the problems I have in watch repair is if I solve a problem I move on. In other words I vaguely recall may be perhaps with a staking set but I can't quite remember. I remember having to do a couple of different similar watches and I don't remember which one that I tightened up and I'm still guessing I did it with staking set but just don't remember in yours does not look quite right.

[Knebo]

Hi @Bonefixer,

@Jon has the answers for you in this thread/post, with a brilliant power point presentation (attachment in the post linked below).

 

 

Edited February 18 by Knebo

[Bonefixer]

Thank you. Again. Excellent presentation from @Jon  

I now know how to do it, whether I can justify getting a staking set however is another matter - seems to me a rather lavish outlay to repair a part I can get from Cousins for £5. 
 

So second question - should I invest in a staking set or just keep on replacing bits as I go?

[AndyGSi]

4 minutes ago, Bonefixer said:

Thank you. Again. Excellent presentation from @Jon  

I now know how to do it, whether I can justify getting a staking set however is another matter - seems to me a rather lavish outlay to repair a part I can get from Cousins for £5. 
 

So second question - should I invest in a staking set or just keep on replacing bits as I go?

It depends what your intentions are going forward with watch
repair whether or not you'd get the use from a staking set.

In this case I'd just go for the replacement, put the other to one side and if
you get a staking set down the line it gives you something to practice on.

[Knebo]

49 minutes ago, AndyGSi said:

It depends what your intentions are going forward with watch
repair whether or not you'd get the use from a staking set.

In this case I'd just go for the replacement, put the other to one side and if
you get a staking set down the line it gives you something to practice on.

That's great advice 

[Bonefixer]

On 2/18/2025 at 11:15 AM, AndyGSi said:

It depends what your intentions are going forward with watch
repair whether or not you'd get the use from a staking set.

In this case I'd just go for the replacement, put the other to one side and if
you get a staking set down the line it gives you something to practice on.

Great advice, which I disregarded and bought a staking set anyway. I now feel like a proper watchmaker and have used my £750 staking set to fix a part in a watch that I could have replaced for £5.95

I can always re-sell it if need be