Cannon pinion problem.

[Neverenoughwatches]

Hiya watch folks. I'm looking at swapping the cannon pinion on an Oris 291 i fixed up a month or so ago. The movement had an incorrect cannon pinion fitted, same size but for a sweep second family calibre whereas the movement is a sub second, the hole in the end bothered me . So one ive just found in a donor 291 the correct one, problem is a broken center wheel pivot is stuck inside it , probably the original had the same fate. I thought about drilling it out but its certain to damage the bore. The difference between the two looks like a 2 part press fit, one with a blind hole and one open, question is finding a way to seperate the 2 pieces of both cannon pinions to swap them over.

[caseback]

Could you perhaps tap it and insert a screw to get some grip? The risk in that, is that you could be expanding the broken off piece, wedging it tighter in the cannon pinion. 

Have you considered closing the open ended cannon pinion with a bit of solder, or is that cheating

 

[Neverenoughwatches]

1 hour ago, caseback said:

Could you perhaps tap it and insert a screw to get some grip? The risk in that, is that you could be expanding the broken off piece, wedging it tighter in the cannon pinion. 

Have you considered closing the open ended cannon pinion with a bit of solder, or is that cheating

 

I could drill the center wheel pivot with carbide but it will be too hard to put a tap through. I did think about polishing a drop of solder on the end, i would have to pack the inside to stop it sucking in. Might be an option as the 2 pieces could be a tight fit and might buckle while seperating. J do havecan offset cannon pinion remover that might prise them apart. 

If i get the blind one apart i can tap out the broken arbor.

Tapping out the arbor may even push the top off