Omega 23.4 SC seconds wheel

[AlexanderToerzs]

Dear all,

I rescued a gorgeous Omega 23.4 SC movement from the scrap drawer of our local jeweller. Made between 1935 and 1936. It's Omega's first ever movement with central seconds. Before you can remove the barrel bridge I think it's sensible to take out the seconds wheel that connects to the seconds hand arbour - if only I knew how. It looks like it is friction fit. I have the three legged Presto No. 3 tool that you use when pulling out chronograph wheels but am reluctant to use it on the seconds wheel since I don't know what I'm doing. Can someone help please?

Thanks an all the best from Hamburg

Alex

p.s. hard to see in the pictures but the securing disc on top of the wheel is tapered.

Edited January 12, 2021 by AlexanderToerzs
Forgot the p.s.

[JohnR725]

Strangely enough we've discussed this previously sometime within the last month or so.

Then you need a tool which you already have. They show the tool in use at the link below.

https://www.watchrepairtalk.com/topic/16140-tissot-27b-21-guidance/

 

[AlexanderToerzs]

Hi JohnR,

Thank you very much. This thread I have completely missed. And strange indeed since you don't run into a 23.4 SC every other day. Problem solved and thanks again, Alex

[AlexanderToerzs]

Dear all,

since we're at it: I have cleaned all parts of the 23.4 and polished all pivots so far. The central second's arbour that goes through the centre wheel arbour is in dire need of polishing too - even developed a bit of rust close to the pinion. However as you can see in the picture there is nothing really to grab the arbour by on the the other end of the pinion.

Can't put it in the Jacot tool or in the lathe. Could make a wax chuck and shellac it in. Maybe I'm thinking too complicated. What would you do?

Cheers and all the best from Hamburg

Alex

[Nucejoe]

This friction fit, independently driven minute wheel is known to loosen and malfunction if removed/refitted too many times, much depends on how many times it has been removed in the past. Peening the outer end of the hole the minute arbour fits in, doesn't do much good either, so unless remval is neccessary I just leave it where it  is. 

Check the shakes and tg reveals  if there most faults

Regs

Joe

[nickelsilver]

Joe, I know you have this feeling that drive wheels on an extended 3rd wheel pivot go flying around but I gotta say in 20+ years I've never opened a watch with a loose drive wheel and never had a comeback from taking one off and refitting it. The forces here are tiny, and just a little friction is needed. Hands are usually fitted much tighter.

 

As to cleaning up that pinion, it could easily go in a jacot with an appropriate carrier (drive dog) in a lantern, and polished up with either a thin burnisher or polishing paste on pegwood.  It definitely needs some cleaning up. If you have a lathe, try chucking the pinion in the headstock,  the a piece of pegwood in the tailstock, run the lathe slowly and hold the long spindly bit true with brass tweezers while you bring up the chucked pegwood.  Should bore into it, then provide enough support to do the finishing work near the pinion. If the far pivot end is also manky (looks ok in photo) just twirling some pegwood down it should clean it up. Continue pushing the tailstock pegwood in the above example should work.

[AlexanderToerzs]

Dear all,

unfortunately I don't have a lantern in my Jacot set. But here is what I did (stupid enough I deleted most of the pictures of the arbour in the lathe). My lathe motor's slowest is 300 revs. That's still too much so I took my bow and turned the lathe by hand. I mounted the pinion in a 1.2 mm chuck very carefully. Instead of a pegwood I used a rubber polishing stick the jewellers sometimes use and put that in the tailstock. Here is a video I didn't delete

For those interested they are called "EVE Pin Polishers" and are made by company here in Germany called ERNST VETTER GmbH. 

And here is the result:

Not half bad.

@Nucejoe: Altough I've never pulled off a wheel from an extended 3rd wheel before I thought  "...that's what I call a loose fit, that is". Felt absolutely no resistance when levering it off with the Presto-for-5-spokes. I can see your point.

Thanks and all the best 

Alex

Edited January 20, 2021 by AlexanderToerzs
I wasn't done.