doxa 115 weird problem

[gary17]

hey guys

Just finished messing  with a doxa cal 115 movement AKA eta2451 and have noticed a problem. It was very erratic with keeping time even though all tests (weishi) said all was correct.

I reset the hands to 12 and winding it to correct time when i noticed the hour hand does not seem to get to the correct hour number.

So i started again at 12 and turned it 1 complete rotation for 1 hour and the pics you see are what happened as you can see it gets worse with each hour. Before i attack this problem blindly i wandered if any one has come across this before and may point me in the right direction to solve this problem.

cheers

gary

[watchweasol]

Hi  Gary  take the dial off and re fit the hands set to 12 then try again watching the hour wheel and canon rotation, and for any slippage or jumping.

[Nucejoe]

Did it have dial washers, did you put them back on the hour wheel?   

 Hour and minute wheel may be disengaging.  

Push dial plate all the way down, if there is too big of a gap between dial and hour wheel,  the two wheels can  disengae. 

Good luck

[gary17]

hey

Thanks guys will check it out.

cheers

gary

[Repivot]

Another thing to consider since the difference is accumulative is that one of the gears in the dial train (cannon pinion, minute wheel or hour wheel) is not original.

Here's my thoughts. If the cannon pinion or the pinion in the minute wheel is off by just one tooth (say 9 when it's supposed to be 10) the watch will show an error like this. 

Also if one of those 2 pinions has a broken tooth, it may show similar error.

[rodabod]

You can also check the hour hand is secured well by slipping a sheet of plastic underneath and gently lifting. 

[Nucejoe]

 It could be loose canon pinion, which is held by two springs in center of the wheel,  canon pinion can slip due to inadequate friction on the groove. 

A worn tooth may jump over that of the adjacent wheel, Repivot has a real valid point.