Movado 150 balance repair

[Andyclient]

I'm in the process of fitting a new balance staff , my first ever to a Movado 150 cal movement following Marks excellent video of the process on a 1940's Cyma.

Everything was going great until it came to fitting the impulse jewel , which won't fit tightly . I have taken note of Marks video and only pressed it on by hand but it still turns on the staff.

Thought i would ask here as to what might be wrong as i didn't want to mess anything up after getting this far.

The staff came from Cousins and spins lovely and true when fitted into the watch so the staff must be right , i was wondering whether the impulse jewel may be wrong as the watch has clearly had a replacement staff in the past as there are marks to the underside of the balance wheel , it does seem to be up against the shoulder of the staff , so if it is the wrong impulse jewel is there anything i can do to tighten it up ?

Any advice much appreciated

[Mark]

I have come across this before. 

If you feel confident and comfortable you could carefully slightly close the hole on the roller. 

There is a special tool for this but it's quite expensive. You might be able to improvise

 

[Andyclient]

Thanks Mark , I do have a cannon pinion attachment on my jeweling tool maybe i'll give that a go after a bit of practice on a spare balance, it makes me feel better knowing that the problem isn't unheard of , i was a bit concerned as this was the first time i'd attempted a staff as i said so i instantly assumed it was me .

Thanks again Andy

[Mark]

Firstly. Well done so far. It's a great achievement to change a balance staff.

Second, this has happened many times to me.

Third. Be careful with the canon pinion tool as you can easily crush the roller. You may need to sharpen both the stake and punch to be thin enough to fit between the upper and lower parts.

Good luck. And have fun

Sent from my iPhone using Tapatalk

[Andyclient]

Thanks Mark will post an update when i've plucked up the courage , will try a scrap one first