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

    • Welcome to the group Stirky. You can search for just about every subject in the craft here. Don't be afraid to ask if you can't find the answer that may have already been covered ( some ad nauseum LOL ). You don't have to buy Bergeon to get good quality. There are many decent mid-range tools available that will last you a lifetime. Cousins would be a good place to start . Cheers from across the pond ! Randy
    • I picked up a similar amount of these jewels some years ago in a watch and clock fair. Every now and then they come in handy. This week I've got a rubbed in bombe jewel in the balance cock that is cracked and needs replacing. Very handy to have a vintage assortment of these type of jewels!
    • Great diagram with the teeth and pinion count. Simple way to reduce the speed of the hour wheel by the 12:1 minute wheel. Genius and yet so simple. Always good to reinforce the principal by what you have done in your drawing. Keep doing that. I had a drawing on my wall for years showing me this which is very similar to the drawing you have done. Here's a formula to work out the beats per hour of a watch movement. The movement's BPH is dictated by the wheel teeth and pinion count and the hairspring being vibrated to the correct BPH by finding the pinning up point on the hairspring using a vibrating tool.  The reason in the formula there is X2 on the top line is because there are two pallet stones.
    • So I just wanted to say "thank you" again.  The angle is the key bit it seems and yes, it did basically just fall, or float, back into position when I got it lined up just right. I had meant to add that now that I see how it goes in, I totally see how it came out in the first place, and that whomever cloned the original movement didn't pay much attention to the fine details around the setting or how it interfaces with the balance cock or the "rings" on the regulator and/or stud carrier arms.
×
×
  • Create New...