Omega 861 "Stuck broken screw" :-(

[Endeavor]

Hello All;

I know pretty well the history of this 1975 Speedmaster Mark II, it used to be my brothers, and somewhere along the timeline a watchmaker has twisted / sheared the top of a screw, holding the operating lever 1720, off.

I discovered this when I first got my hands on this watch in 2017: https://www.watchrepairtalk.com/topic/6842-omega-861-speedmaster-mark-ii/

At that time I didn't succeed to get the remaining part out. The screw-head is literally hanging on onto one thread. The screws acts as a "guide" for the lever.

The stuck piece sits just below the edge of the bushing (barrel / train bridge)

On the other side the screw seems to be a bit tapered.

I tried with two pieces of peg-wood, one on either side, with friction to screw the part out, but no joy. Two small screwdrivers just slip over and I don't want to damage that little piece of thread the screw-head is just hanging onto?

I don't have a fancy broken-screw remover and of course, there is a reason why the head was twisted off; the remaining part must be pretty stuck.

Has anybody some good tips which I could give a try?

 

 

Edited January 7, 2023 by Endeavor

[Fredrik]

Hi Endeavor!

I'm quite new and started out with some old pocket watch movements and twice I've run in to this problem.

First I tried to drill it out by mesuring the diameter of the screw and trying to drill with a smaller size drill as to create an opening with threads around, force a V-shaped screwdriver in and try to get it out that way.

I failed though. The drill managed go drill away the screw, threads and now I have a hole, slightly lager (1,2mm)and my next course of action will be to get a new threading in and purchase a screw that will fit and eventually I think I can salvage it.

I think I failed because of lack of hugg precision tools, used a regular powered drilling machine and it couldn't quite grip the 1mm drill so I guess it wabbled ever so slightly.

As I mentioned I have a another screw stuck in ny father-in-laws old family pocket watch so I hope someone wiser and more experienced will enlighten you and me both. You can kinda view what I did more or less as a "What not to do"

Cheers!

Fredrik

[Fredrik]

Endeavour! I was sleepless last night and asked uncle Google and found something called "a screw extractor tool" 

Cousins has the Bergeon one and chinese more affordable option

https://www.cousinsuk.com/product/screw-extractor-bergeon-swiss?code=S1517

This hobby isn't a cheap one.... But I grow richer in tools as the days go by  I chose the cheaper option, 30 £, since I hope this isn't a tool I will need that frequently and there are always things to spend money on. I will post again once it has arrived and I can tell you more about it.

Cheers!

[RichardHarris123]

Try gluing a old screwdriver shaft to it. The glue can easily be dissolved later if any gets on the tread. 

[GuyMontag]

14 hours ago, Fredrik said:

Endeavour! I was sleepless last night and asked uncle Google and found something called "a screw extractor tool" 

Cousins has the Bergeon one and chinese more affordable option

https://www.cousinsuk.com/product/screw-extractor-bergeon-swiss?code=S1517

This hobby isn't a cheap one.... But I grow richer in tools as the days go by  I chose the cheaper option, 30 £, since I hope this isn't a tool I will need that frequently and there are always things to spend money on. I will post again once it has arrived and I can tell you more about it.

Cheers!

The Chinese versions that I have looked at seem to have different extractor tips than the Bergeon one. The Chinese ones look like they are meant to drill the screw out vs. the Bergeon one where the extractor tips have a "claw" on the tip to grab the screw with friction and then you twirl the plate the screw is in and it backs the screw out. So I'd be interested in hearing how the Chinese version works for you when you get it. I also wonder if the Bergeon extractor tips, which can be purchased separately, would fit in the Chinese version.