Benrus DN21 stem question

[Rhobin]

I bought a Benrus DN21 movement as one of my first to practice on. I have attached an image of the movement.

From what I can find out, it is an ETA 1280 or 1281. The main plate has the ETA mark, but no calibre number.

The movement arrived with the crown/stem stuck fast. The dial had some staining, so I assumed there would be some rust in the keyless works.

As I disassembled the movement, everything looked clean and undamaged, but the stem was held fast in the main plate.

After I stripped the movement, I managed to extract the stem. I had assumed the stem had rusted and wedged itself in the main plate, but the stem didn't look as I expected. I've attached an image. What confused me was the black section by the thread.  Does anybody know what it is? Is it a collar to prevent water ingress?

I've tried to find a technical reference to see if I could identify it, but I'm having difficulty.

I'm hoping that I can just get a replacement stem and everything will be good.

Any thoughts or suggestions about this would be welcome.

Thanks
Robin

 

[jdm]

1 hour ago, Rhobin said:

the stem didn't look as I expected. I've attached an image. What confused me was the black section by the thread.  Does anybody know what it is? Is it a collar to prevent water ingress?

Maybe a poor quality stem that had been replaced or cobbled up? I would start checking well the bore in the plate and getting a new stem.

[watchweasol]

Hi Have a google at Ranfft  benrus DN 21, you will find out its the ETA 1281  and it quotes the stem as W2120. I have been unable as yet to find any tech sheet for it but Ranfft has quite a bit of info .     The site  windingstems.com is another source to be explored.. There is of course the possibility of attaching an extender to the stem and re using.

[watchweasol]

Hi Had a close look at the picture.  I should check to see if there is a stem tube fitted to this watch as this looks like its rusted to the stem and come out with the stem attached,  soak the stem in coke for awhile to dissolve the rust and see if it loosens up and comes free from the stem. or it maybe a sleeve from a cobbled job as per jdm.

[Rhobin]

7 hours ago, watchweasol said:

Hi Have a google at Ranfft  benrus DN 21, you will find out its the ETA 1281  and it quotes the stem as W2120. I have been unable as yet to find any tech sheet for it but Ranfft has quite a bit of info .     The site  windingstems.com is another source to be explored.. There is of course the possibility of attaching an extender to the stem and re using.

Thanks. I had found the Ranfft reference, but I couldn't find any reference to W2120 - probably due my lack of knowledge than availability.

I've found some stems for the ETA 1280/81 on ebay, so I was planning to order one of those.  I hadn't heard about windingstems, so I'll check that out. Thanks!

[Rhobin]

56 minutes ago, watchweasol said:

Hi Had a close look at the picture.  I should check to see if there is a stem tube fitted to this watch as this looks like its rusted to the stem and come out with the stem attached,  soak the stem in coke for awhile to dissolve the rust and see if it loosens up and comes free from the stem. or it maybe a sleeve from a cobbled job as per jdm.

I don't have the case for this watch. It was just a movement I bought for cheap that was sold for parts/repairs that I got to help learn.

I'll give the coke a try and see what happens. Thanks.

[Nucejoe]

No wonder why this stem was stuck, its so dirty.