Montine automatic

[Gra]

I recently bought a Montine watch on eBay to practice on.

Stripped it cleaned it and rebuilt it, but could not get the hands to turn with the crown. Posted a thread and got some great advise from members, this caliber (AS 5203) has a captive canon pinion which has to swivel on its cog, mine didn't. I soaked the gear in Moebius 8000, cleaned it then oiled again, it now turn but has slight resistance, not sure if that's how it should feel, however having rebuilt the watch it has poor amplitude.

I have rebuilt it several times now, amplitude is still poor however it will run for 2.5 days on a full wind while in movement holder, balance up. If I turn it over it stops in seconds.

Anyone any ideas I'm at a loss.

Graham

 

[Skutt50]

It is not easy to guess what your problem could be. There are several possibilities.....

An initial guess would be that you have a balance problem. Did you clean all balance jewels? Did you check for cracks?
Are the balance pivots clean, mirror shiny and straight?

You can test the balance as follows:
Remove the pallet fork
Re install the balance and give it a small push.....
It should start oscillating and continue to do so for at least some 20 seconds. Test it in various positions....
If it does swing nicely in all positions the problem is probably located elsewhere in the gear train......

 

[Gra]

It is not easy to guess what your problem could be. There are several possibilities.....

An initial guess would be that you have a balance problem. Did you clean all balance jewels? Did you check for cracks?
Are the balance pivots clean, mirror shiny and straight?

You can test the balance as follows:
Remove the pallet fork
Re install the balance and give it a small push.....
It should start oscillating and continue to do so for at least some 20 seconds. Test it in various positions....
If it does swing nicely in all positions the problem is probably located elsewhere in the gear train......

Thanks Skutt,
Took the pallet fork out and tried the balance wheel, (both pivots are clean and intact) it ran for longer dial side up than balance side up so removed, cleaned and oiled the balance jewels.
Seems to be running stronger now both ways up. I can't afford a timegrapher at this point so will see how it runs in various positions over next few days then if everything ok will complete the rebuild.
Just as a note, once pallet fork was removed, every now and then the escape wheel would spin for a few seconds as more residual power was released from main spring. This happened about 3 times so I'm wondering if there is some resistance in there somewhere.

 

[gmorse]

Hi Graham,

Just as a note, once pallet fork was removed, every now and then the escape wheel would spin for a few seconds as more residual power was released from main spring. This happened about 3 times so I'm wondering if there is some resistance in there somewhere.

When you cleaned the watch, did you remove the mainspring from the barrel?

The symptoms of the balance suggest that the top staff pivot may be flattened at the tip, so it's worth looking very closely at that.

Regards,

Graham

 

[Gra]

Hi Graham,



When you cleaned the watch, did you remove the mainspring from the barrel?

The symptoms of the balance suggest that the top staff pivot may be flattened at the tip, so it's worth looking very closely at that.

Regards,

Graham

Hi Graham, to be honest I opened the barrel and it did not look particularly dirty so left it.
To clean it would mean removing and replacing by hand, suppose I should do this as I am here to learn and bought the watch to practice on.
The pivot tips look fine through my 15x loupe and having cleaned and oiled the jewels again seems much improved.

 

[Skutt50]

Once you have the pallet fork removed you can also check the gear train by turning the winding crown slightly. The gear train should rush and the escape wheel should come to a distinkt halt. If it slows down and speeds up and/or behaves oddly at the end you need to rework the gear train i.e. check all pivots, check all gears and check all jewels for dirt or cracks......

On e.g. pocket watches you can often find that the escape wheel comes to a halt and then spins slightly backwards. (Backlash).

 

[Gra]

Cleaned and refit the mainspring, fitted the new cannon wheel and rebuilt.

Been wearing it for 2 days now and it's running perfectly.

Thanks to you all for your input it has been invaluable.

Graham