 The Clarinet BBoard
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Author: stevensfo
Date: 2006-10-23 13:40
I was going to remove the register key from an old clarinet and found the screw wouldn't turn. Tried a bit harder and discovered that I'd destroyed the head and now the screwdriver won't grip. Never had this happen before. The screw actually looks different from the others, so perhaps someone replaced it with a softer metal screw in the past.
Does anyone have any ideas? I thought of drilling into the centre and tapping a small phillips type screwdriver into the hole, but I may end up making it worse!
Steve
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Author: tictactux ★2017
Date: 2006-10-23 14:06
Your best bet is to drill it out from the opposite (ie threaded) side, using a drill of max. half the diameter of the screw. (if you drill from the screw head side, you risk making it stick even harder)
Make sure the whole thing is properly lubricated as the heat from drilling will expand the material, and use a vise to ensure proper alignment of screw and drill.
If you manage to destroy the thread on the pillar, you can fill it with epoxy (or solder) and re-cut the thread, or replace the pillar entirely.
--
Ben
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Author: RAB
Date: 2006-10-23 14:26
Stop!!!!!
Take the instrument to a qualified repair person, There are many things that could go wrong, breaking off a post, snaping a key, etc...
If you don't want to do that put some penetrating oil on the key where it enters the post and where the key hinge tube meets the post. apply some heat to the hing tube in order to draw the oil into the tube. You may have to repeat this several times. It might work.
A qualified repair person will have tools to remove the screw and restore the key to proper fit.
RAB
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Author: BobD
Date: 2006-10-23 15:02
"Been there....and still there". TicTac's advice is probably best. I am currently in exactly the same position plus. Having tried all the normal suggestions, penetrating solvent, heat, drilling etc. I recently purchased a mini screw extractor set from Micro Mark that I'm trying but without success so far. Drilling from the threaded end makes a lot of sense since the clockwise rotation of the drill bit will tend to help loosen the screw. Experts will sometimes saw through the screw between the post and tube...at one end or both. By the way, my clarinet was previously owned by a well known clarinetist who buggered more than one screw on the horn.
Bob Draznik
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Author: stevensfo
Date: 2006-10-24 13:14
Thanks for all the advice. I'll give it a go in a few days. I like the idea of drilling from the other end to loosen the screw. It makes sense. Fortunately I bought a set of tiny drills for my dremel last year so I'll get to try them out.
As well as drawing the oil in, I imagine heating the tube will help slightly by expanding it slightly, and maybe loosen up on the screw inside.
Steve
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Author: BobD
Date: 2006-10-24 15:13
That vertical Dreml holder would be a good idea as freehanding could do you in. Good luck on the tube expansion.....it could expand all directions.
Bob Draznik
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Author: stevensfo
Date: 2006-11-04 13:41
Just a quick update. I tried drilling from the other side and it didn't seem to do much. BUT it clearly loosened the screw enough for me to push a small phillips screwdriver into the mangled head and unscrew it.
Needless to say the screw will receive a liberal coating of key oil before going back!
Steve
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Author: John O'Janpa
Date: 2006-11-04 15:49
Please don't use the same screw unless you can restore the head and slot.
Easier to use another screw like it.
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Author: clarnibass
Date: 2006-11-04 15:55
"Needless to say the screw will receive a liberal coating of key oil before going back!"
After what you described you did to that screw it doesn't sound like you would want to use it again, if even possible!?
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Author: tictactux ★2017
Date: 2006-11-04 16:27
> After what you described you did to that screw it doesn't
> sound like you would want to use it again, if even possible!?
That were my thoughts too - I was under the impression that the screw head was, well, screwed anyway.
The problem with grooved/slitted rods (it doesn't have a screw head in the narrower sense) is that they tend to be forced apart in the groove area, especially when a chisel-headed screwdriver is used. And the harder you try the more it will splay and the more it will stick against the pillar hole.
--
Ben
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Author: BobD
Date: 2006-11-04 18:58
and if the screwdriver isn't just the right size the problem is aggravated.
Bob Draznik
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Author: stevensfo
Date: 2006-11-04 20:48
Thanks guys. It's just temporary. It won't be going in all the way. I'm not falling for that trick again!
Steve
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Author: Gordon (NZ)
Date: 2006-11-05 10:46
1. The problem arose because of poor technique for removing stuck screws. The screw driver needs to be the exact size tip, with a very SHARP tip, of excellent quality, with a long handle, and plenty of handle diameter. Heat and penetrating oil should have been used. A key rocking technique should have been used during the removal process. If these are done, then it is very, very rare to wreck a head before removing the screw.
So, take such problems to a technician who has the experience and the equipment!
2. I drill through the threaded end if necessary, using freehand drilling, with a dental micromotor unit handpiece (i.e. sophisticated Dremel). I find freehand (hand-held instrument AND hand-held tool) FAR more suitable, because there is constant feedback to the operator via finger nerves, and through being able to easily sight (for alignment) . If this were not the case, dentistry and surgery would be in a pretty sad state!
3. Rather than drill through the threaded end, I now use a very small burr, and work on the end of the other end of the shaft, INSIDE the post (without marring it) to re-create (i.e. mill) a screw driver slot.
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Author: BobD
Date: 2006-11-05 15:16
"3. Rather ".....Now...that's precision.
Bob Draznik
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Author: stevensfo
Date: 2006-11-05 17:22
-- "So, take such problems to a technician who has the experience and the equipment!" --
Gordon, I assure you that had it been an expensive instrument, I wouldn't have touched it. This was in fact a very old and worthless piece of junk that has been taken apart and fiddled with more times than I remember in an attempt to make it play better and to practise my own repair skills.
For the average player, I agree that he/she would be well advised to 'take it to a repair tech', but the great thing about this forum is that it allows us to discuss all manner of repair techniques in a friendly setting and I have to say that because of this, I have learnt a tremendous amount over the past few years. Yes, it was a pain to remove the screw, but a great learning experience.
-- "I now use a very small burr, and work on the end of the other end of the shaft, INSIDE the post (without marring it) to re-create (i.e. mill) a screw driver slot." --
Actually, I would have liked to try that but didn't have a small enough drill. Oh, and our dentist was away for the weekend! ;-)
A great idea! I will be spending some time in the Dremel accessories catalogue.
Steve
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