Jump to content

Removing Sheared Off Screws grrrrr


jnash

Recommended Posts

So i usually use Alum powder, however on of the screws have been sheared off  look to be within a steel boss so therefore worried it will eat the hub along with the screw.

unless i can replace the hub, i will have to resort to loosing up / heating ... drilling. 

 

IMG_20171103_095045.jpg

Link to comment
Share on other sites

8 minutes ago, Andyclient said:

Bergeon do a screw extractor tool no:30209 but whether it would work here or justify buying i don't know , maybe if someone has one you could borrow ?

The Bergeon 30209 is a useful piece of kit to have in your armoury but it has 2 significant limitations.

  1. It can only be used on through holes as it has to be in contact with both ends of the broken off screw. If the screw is in a blind hole it can't be used.
  2. At ~£76 plus postage it suffers from severe "Bergeonitis". It's an expensive piece of kit to have sitting in your draw on the off chance that you're faced with a situation that can't be addressed with alum.

I was lucky, I found mine at a car boot sale for less than £1 (for my £1 I picked up the 30209, a very nice canon pinion tightener, and something else I can't remember what) minus the runners. It took me all of about 5 mins to knock up a set of runners out of blue pivot steel on the lathe, and in 5 years I have only used it about 3 times; on that basis I could not have justified the cost of new. It is however a very simple concept and could make a very nice DIY project for someone with some basic kit. If pushed I reckon I could make a workable version from scratch using basic hand tools and perhaps a pillar drill.

@jnash I think that if that steel insert is blind drilled then you best option is probably to use a very sharp graver point to try and key into the top of the screw to turn it. So long as the bottom of the screw isn't jammed hard into the end of the blind hole, in other words if it sheared because underside of the head was hard against the top of the insert, and there is no corrosion causing the threads to bind, then you have a good chance of success. If however it is binding then hot/cold, penetrating fluid may be you're only option short of either drilling out the screw or even replacing the steel insert altogether.

  • Like 2
Link to comment
Share on other sites

1 hour ago, Marc said:

The Bergeon 30209 is a useful piece of kit to have in your armoury but it has 2 significant limitations.

  1. It can only be used on through holes as it has to be in contact with both ends of the broken off screw. If the screw is in a blind hole it can't be used.
  2. At ~£76 plus postage it suffers from severe "Bergeonitis". It's an expensive piece of kit to have sitting in your draw on the off chance that you're faced with a situation that can't be addressed with alum.

I was lucky, I found mine at a car boot sale for less than £1 (for my £1 I picked up the 30209, a very nice canon pinion tightener, and something else I can't remember what) minus the runners. It took me all of about 5 mins to knock up a set of runners out of blue pivot steel on the lathe, and in 5 years I have only used it about 3 times; on that basis I could not have justified the cost of new. It is however a very simple concept and could make a very nice DIY project for someone with some basic kit. If pushed I reckon I could make a workable version from scratch using basic hand tools and perhaps a pillar drill.

@jnash I think that if that steel insert is blind drilled then you best option is probably to use a very sharp graver point to try and key into the top of the screw to turn it. So long as the bottom of the screw isn't jammed hard into the end of the blind hole, in other words if it sheared because underside of the head was hard against the top of the insert, and there is no corrosion causing the threads to bind, then you have a good chance of success. If however it is binding then hot/cold, penetrating fluid may be you're only option short of either drilling out the screw or even replacing the steel insert altogether.

I agree Marc I have one (purchased new) & I have only used it twice in as many years. However it is handy.

Link to comment
Share on other sites

I bought a set of these cheapies from Esslinger and believe it or not , I have used them about 4 or 5 times and have had success each time .

  Some screws came out easy , but some of them I used a bit of penetrating oil first , then put the watch plate in a bit of warm water in my  ultra sonic cleaner for a while to vibrate the part . 

 

59ffae2ad5c6e_ScreenShot2017-11-05at2_28_38PM.thumb.png.98387253db1a0be7db429319a9b66a0c.png

59ffae423028b_ScreenShot2017-11-05at2_29_09PM.png.9f8af51caee2a39a5b4efb165811a61e.png

59ffae5206618_ScreenShot2017-11-05at2_28_52PM.png.e0c071009a1c506d888af8e3e269664d.png

  • Like 1
Link to comment
Share on other sites



  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • I missed this earlier. The dial isn't going into the holder, it should sit proud of it. This is what I am currently using which I print for each different movement.    
    • I didn't think pulling to set position would work harden the spring, in that position it is stressed where the arm starts. By work hardening i meant rapid polishing at that point, a bit like polishing a pivot work hardens as it compresses the steel. I doubt polishing by hand would achieve much in that respect though. Its finished, arm polished up mostly at the join to the bridge's main body. I'm ok with it, the screw holes aren't great as i had to open them up by redrilling and positioning it was difficult, I'm not much use with a loupe, opening up with a file might be a better option for me or i could just use the correct drill size 😅. And the detent is way too deep, i had to guess that with the stem release out of position and sat on top, but i only took one measure and went for it, no slowly slowly catch your monkey 😅. First go I'm happy , well sort of, it works and thats a big thing for me, next one will have a bit more finesse.  Anyone thats interested, after filing, i used a 2000 grade home made diamond  micro file and then 20 micron film, the film is much better than wet and dry, more stable to use and doesn't shed cheap grade grit everywhere , then auto polish on a sponge pad.
    • I'm assuming that every time you set the watch you are work hardening the detent spring, maximum hardening is  where it meets the plate due to maximum deflection.   That's why it snaps there.  The Young's modulus may be the same but after it's reached its maximum yeid strength it breaks.  My mechanic engineering is very rusty, correct me if I'm wrong. 
    • Ah ok yes that makes sense to polish it where the arm starts to form from the body of the bridge, i thought you meant the underneath of all the arm.
    • this is something I've never quite understood about the some of the Swiss companies. In 1957 Omega was using 9010 for the keyless parts with epilam. there's been a slow migration towards using heavier lubrication's but still typically oils and epilam to keep them in place. When it seems like 9504 works so much better.  
×
×
  • Create New...