Hi all, I know it's important to test the power train for backlash in a pocket watch, but I have not been able to get my wristwatch power trains to perform this feat after cleaning and re-assembly. Should I continue to strive for this ideal, or is it less achieveable in wristwatches?

Thanks, Jim

You should get backlash,even in a wrist watch. Did you replace the mainspring?

Hi:

You also need to check for end shake in each wheel, all the way back to the barrel. The barrel arbor has to have end shake when the barrel is assembled, and the barrel arbor has to have end shake when the barrel is installed in the watch. I am running into more and more older wrist and pocket watches with end shake problems in both the gear train and mainspring.

Best Regards,
Steve Settle

I agree. Folks just don't seem to treat the mainspring barrel as the first-wheel, which it is.

I have had problems with the Bunn Specials that use those three screws to hold the mainspring barrel. They can easily set the barrel non-level, in which case it is likely to bind.

hmmm... maybe I have been barking up the wrong tree. I have been believing that it was a cleaning problem, but it may be a mainspring issue. There is endshake in the barrel and the whole power train. Just one click on the mainspring sends the escape flying, but no backlash.

How would I determine whether or not I have a weak mainspring? The watch runs for about 30 hours on a full wind.

The watch in question at this time is a Bulova 7AK.

Take the mainspring out of the barrel if it does not straighten out quite a bit you should change it..A mainspring that stays coiled up is what we call set.I have bunches of the white mainsprings for the 7ak if you need one i would be gald to mail one to you..

Have you checked all the jewels one could be cracked look good at both the jewels on the center wheel.
good luck

Well Samie, The mainspring is good. It laid out into a nice "S" shape. Picture book perfect. The only trouble with that part is getting the little bugger back into the barrel. I can't seem to hook the end into it's notch. Is there a trick? I guess patience will serve me well in that area.

All of the jewels seem to be OK, but you said "both" jewels on the centerwheel. There is no jewel on the plate. It just goes through a hole. No bushing or anything. I don't think I oiled that spot last time I put it together. Maybe that will do the trick.

Thank you for your kind offer of the spring, but fortunately I won't need it. I would still like to talk to you about that Illinois grade 903 movement if you still have it. I can't mail or PM you since I am not yet a member of 185. Hopefully that will be resolved soon. My E-mail address is: okrobie@thewebplace.com.

Regards, Jim

Added Later: I got the spring back into the barrel.

Yeah!!! I got backlash on this 7AK. I learned an important lesson through it though. I was just oiling jewel holes and forgot the center wheel going through the plate. I also learned how to take a mainspring out (and put it back ).

Thanks to all.

Regards, Jim