bellmatic problem

[craigant]

hi all, i got my first bellmatic today and what a watch, was much better than i expected by the pic in the ebay auction. the seller said it runs and stops but what happens is the second hand runs all the time and just the minute and hour hands work sometimes. they will work for maybe 20 min and then stop while the second hand keeps on ticking away nice and strong. what would cause this to happen? is it just a case of a service or would it be a sign of a nasty problem? also does anyone know where i can get a removable link for the bracelet that is showen on the watch? I have another two bell matics coming as well this is addictive lol
many thanks
craig

[Joe Horner]

Hi Craig. If you haven't got this sorted yet, it's almost certainly a loose cannon pinion causing your problems. The cannon pinion acts as a clutch between the movement and the hour / minute hands to make it possible to set the time - if the hands had a completely solid drive then, when you tried to set the watch, you'd have to spin the entire train, which you can't do because (a) the escapement won't let you and (b) if you managed it, some of the wheels would end up spinning very fast indeed. Over time the pinion can wear loose and start slipping, which means that the movement keeps running but the main hands either don't move or move intermittently. You'll probably find if you try to set the time that it feels very "light" when you turn the crown?

The good news is that checking / tightening it should be part of a standard service so you're unlikely to face any nasty bills as a result