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Deggsy1969
·I recently serviced an ETA 2892A2 movement and the amplitude at full wind is 300deg and after 24h is 225deg. The reserve is a little low at 38hours but I’m not overly worried about that just now.
My main problem is that the automatic wind mechanism will not work efficiently and the watch stops after 2days of wearing from full wind (it’s taken off at night). I confess that the reverser was not exchanged but cleaned and relubricated with V105. I can’t see and fault with its operation when revolving the weight in either direction the movement is being wound.
The oscillating weight is quite sluggish when the watch is moved. It’s not binding anywhere but there is a definite reluctance for it to spin freely as expected and will easily get hung up at the top (opposing gravity)
I removed the weight, mounted it on a tapered mandrel and although not stiff it seems very damped. I cleaned the bearing through and repeated this experiment with no oil, small oil (9010) and finally oil on all the balls in the race. The difference was negligible.
I compared the freedom of spin to a known good 7750. Chalk and cheese!
Thanks for sticking with me this far! I wanted to give as much detail as possible that might help you help me.
My question is, are such winding issues in the eta 2892A2 automatic winding usually attributed to the bearing and reverser wheel, or can it also be at the ratchet driving wheel etc under the barrel bridge?
The movement feels normal and smooth when wound at the crown, no unexpected resistance.
I’d be grateful for any help that can be offered please
Kind regards
Darren
My main problem is that the automatic wind mechanism will not work efficiently and the watch stops after 2days of wearing from full wind (it’s taken off at night). I confess that the reverser was not exchanged but cleaned and relubricated with V105. I can’t see and fault with its operation when revolving the weight in either direction the movement is being wound.
The oscillating weight is quite sluggish when the watch is moved. It’s not binding anywhere but there is a definite reluctance for it to spin freely as expected and will easily get hung up at the top (opposing gravity)
I removed the weight, mounted it on a tapered mandrel and although not stiff it seems very damped. I cleaned the bearing through and repeated this experiment with no oil, small oil (9010) and finally oil on all the balls in the race. The difference was negligible.
I compared the freedom of spin to a known good 7750. Chalk and cheese!
Thanks for sticking with me this far! I wanted to give as much detail as possible that might help you help me.
My question is, are such winding issues in the eta 2892A2 automatic winding usually attributed to the bearing and reverser wheel, or can it also be at the ratchet driving wheel etc under the barrel bridge?
The movement feels normal and smooth when wound at the crown, no unexpected resistance.
I’d be grateful for any help that can be offered please
Kind regards
Darren
