Help on an ETA 2391

[Delgetti]

Hello,

does anybody here know the ETA 2391 or a similar movement? I have to reassemble this one and I have to admit that I don't really understand how the time setting works.

I only know the standard design on other movements with a cannon pinion. When you set time, the cannon pinion slides over the minute tube.

But on this ETA 2391 there is no seperate cannon pinion, it seems to be fixed to the minute wheel. But how does time setting work with this? Which part can do the sliding? Thanks for any help.

[Chopin]

When I disassemble movements unknown to me (which is almost all of them haha...) I take pictures of, almost, every part that I remove. Wish I could help more.

Edited September 18, 2017 by Chopin

[FlyingWatchmaker]

It's a standard for the eta movements, the wheel that sits under the cannon pinion has (in this case) 3 arms that provide pressure for the hands to run, and let the cannon pinion slip for hand setting.

The drive of the movement comes through the 4th wheel pinion (7 o'clock on the picture shown) directly to the wheel under the cannon pinion.

I don't recommend dismantling the wheel, unless you have a spare, as the tension is critical to keep the watch running.

Tom

[Delgetti]

@FlyingWatchmaker: Thanks a lot. So the cannon pinion isn't totally fixed to the wheel, but can rotate against it. I couldn't spot that on my watch. Maybe a little amount of grease is needed here as the part was cleaned?

I will try reassembly during the next few days and give a feedback here.

[rogart63]

9 hours ago, Delgetti said:

@FlyingWatchmaker: Thanks a lot. So the cannon pinion isn't totally fixed to the wheel, but can rotate against it. I couldn't spot that on my watch. Maybe a little amount of grease is needed here as the part was cleaned?

I will try reassembly during the next few days and give a feedback here.

Very very little grease. Some say no oil or grease  but i use HP1300 . I check that it's tight by slightly trying to rotate the inner part. You get a fell for it when you service a few of them. 

[Delgetti]

Ok, I reassembled the keyless works and the wheels for time setting yesterday evening and it works.

Thanks to FlyingWatchmakers advice I knew where to look. Here is a pic of the downside of the minute wheel. Easy to spot the 3 mentioned areas which work as springs. I put a very little amount of 9501 in this area and blocked the minute wheel to test. Time setting works with a good feeling of some friction.