Twisted Stem

[Klassiker]

I have just disassembled an ETA 2789 (at least that's what's marked under the balance. It doesn't have the day display) and found the square of the winding stem to be twisted. The function of the watch doesn't seem to be impaired. Winding and setting work fine. My question is, how can this happen? It's a seemingly perfect twist (no bend), and too much torque on the crown would surely cause breakage somewhere else before the square twists. So was it made that way? Why? I've never seen or heard of anything like it.

[oldhippy]

Some are made that way. I found this type make it easier when inserting.  

[Chopin]

Indeed this is one of those movements that uses a twisted stem... No worries.

Usually I've found these on ladies calibers... Never on men's but who knows...

[jdm]

5 minutes ago, Chopin said:

Usually I've found these on ladies calibers... Never on men's but who knows...

ETA 2824-1 is like that. I think the idea is that the twist helps the setting lever in keeping the castle wheel pressed.

[WatchMaker]

Also look at this previous topic: https://www.watchrepairtalk.com/topic/9116-eta-2824-2-stem-question/

[Klassiker]

Thanks everyone!

[jdrichard]

My wife's Squale Diver had a twisted stem and when I cleaned and repaired it I thought I had to bend it back. Lucky I stopped to think.

Sent from my GT-N5110 using Tapatalk

[LittleWatchShop]

I have a watch with a twisted stem.  Like others, I thought it was a problem.  After researching, I discovered that it was ok.  Searched the forum to find this thread which is helpful, but still scratching my head as to how a twisted stem makes things work better. 

In the worst-case scenario, could it be replaced with a straight stem?  Just curious...not an issue for me now.

[Nucejoe]

55 minutes ago, LittleWatchShop said:

but still scratching my head as to how a twisted stem makes things work better. 

The twist drives the winding and sliding pinions towards each other which enhances the grip for their clutch action. 

[LittleWatchShop]

1 minute ago, Nucejoe said:

The twist drives the winding and sliding pinions towards each other which enhances the grip for their clutch action. 

Ahhhh...I see it now.  Blinding glimpse of the obvious!  Thanks!!

[Nucejoe]

Just now, LittleWatchShop said:

Ahhhh...I see it now.  Blinding glimpse of the obvious!  Thanks!!

I didn't say it quite right in previous post. Actually only the sliding pinion gets driven towards the winding pinion.