 The Clarinet BBoard
|
Author: Tony F
Date: 2016-07-13 08:48
Many years ago, in another life, I frequently had problems with tight screws. Much like the problems that we experience here but on a much larger scale. One of my colleagues used a tool of his own devising which used a rotary vibrating module to vibrate a screwdriver blade. This was quite effective on tight screws and I'm considering if something similar but on a smaller scale would be of use in the instrument repair field. Has anybody come across such a tool?
Tony F.
|
|
Reply To Message
|
|
Author: WhitePlainsDave
Date: 2016-07-13 17:15
Tony, might you be able to add some clarity for me as to these screwdriver movements?
I am envisioning a screwdriver that rotates around a vertical axis (i.e. torsional energy), as screwdriver's do, but that also, examining the [flat?--i.e. non-Phillips head] screwdriver head from above, in any one instant that the screwdriver head is at a particular rotational angle, that you'd also find the head oscillating towards and away from the screwdriver's operator...???
Is that it?..or maybe you refer to a hammer like action (i.e. a hammer drill) where torsional energy is enhanced by a concurrent hammering action?
Still more, in the world of musical instrument screw stabilization, where thread stripping can come from sheer muscling of a screw, I am far more a proponent of CA type glues (i.e. Cyanoacrylate--Crazy or Super Glue type glues) on the threads just prior to torquing them in.
Also, at least in the States, products like Loctite (I'm sure its sold down under, if not by a different name) are useful for such situations.
Good luck.
|
|
Reply To Message
|
|
Author: Tony F
Date: 2016-07-13 17:27
In this case the vibration was applied to rotate the screwdriver, and the particular use I envisaged is in the loosening of screws, not the tightening of them. In the original tool, as long as the screwdriver head was held firmly in the slot with as much rotational force as was necessary to apply a turning motion to the screw, when the vibrator was turned on the offending screw would gradually work its way loose and unscrew. It worked in much the same way as a car wheel nut tightener, or "Rattle gun".
It was important that the screwdriver head was a good fit in the slot. I have never seen a tool like this on the scale that we would need it, but if it performs as well as the one that I saw it would be useful indeed.
Tony F.
|
|
Reply To Message
|
|
Author: tictactux ★2017
Date: 2016-07-13 21:44
bzy an ultrasonic toothbrush. File the metal rod (where you plug the brush head onto) flat in screwdriver style. :-)
--
Ben
|
|
Reply To Message
|
|
Author: Tony Pay ★2017
Date: 2016-07-13 23:31
The very idea of a screw is that it is reversible.
Sometimes screws on a clarinet fail to provide that reversibility, and that is what the original poster is talking about, it seems to me.
I don't know the answer to his question, but I think it's an interesting contribution to the problem.
That you bring superglues into the discussion amazes me.
Tony
|
|
Reply To Message
|
|
Author: Chris P
Date: 2016-07-13 23:51
If you are going to use superglue as a thread locking agent, apply a tiny drop to the screw thread and let it fully cure before fitting so it's only applying tension to the threads and isn't glueing them in place.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
|
|
Reply To Message
|
|
Author: Tony Pay ★2017
Date: 2016-07-14 00:18
Yes, I can understand that...perhaps.
But he said, "just prior to torquing them in."
Tony
|
|
Reply To Message
|
|
Author: Chris P
Date: 2016-07-14 00:33
Makes my blood boil when I see Leblanc clarinets that have headless point screws and a piece of nylon filament going through the thread having been excessively superglued in place (and a pain in the proverbial to remove them). It's a simple job to either warm the screw up to expand the nylon, or push it out and put in a new piece.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
|
|
Reply To Message
|
|
Author: WhitePlainsDave
Date: 2016-07-14 05:15
Mr Pay:
Seems we might be lost in translation.
I mistook the OP's issue as keeping the screw "in," not getting a "hard to get out screw" out.
Were my wrong assumption the case then CA glue type liquids (Cyanoacrylate--Crazy or Super Glue type glues) are used all the time--as you might know--to keep small screws in place: from those on musical instruments to those on eyeglasses.
"The very idea of a screw is that it is reversible."
Yes, but sometimes they are too much so and come lose (as I'm sure you appreciate.) The CA glue doesn't prevent intended reversibility by the repairer, but rather unintended reversibility by a player's repeated use of said lever, rod, etc. to which the screw's attached.
|
|
Reply To Message
|
|
Author: Tony F
Date: 2016-07-14 06:09
"Like an impact driver?"
More like an "impact un-driver." The movement of an impact driver is quite coarse and violent and would probably wreck the instrument. I have in mind something with a much higher operating frequency at a lower amplitude.
"buy an ultrasonic toothbrush. File the metal rod (where you plug the brush head onto) flat in screwdriver style. :-)"
I had thought of this approach, but I believe (haven't checked it yet) that the motion of the shaft of an electric toothbrush is linear rather than rotational. I'll check it out anyway. Thanks.
Tony F.
|
|
Reply To Message
|
|
Author: Tony Pay ★2017
Date: 2016-07-15 22:06
The two toothbrushes (different Braun models) in my bathroom are both rotational.
I prefer Chris's characterisation of the use of superglue on threads: friction enhancer rather than adhesive.
Tony
|
|
Reply To Message
|
|
Author: Burt
Date: 2016-07-16 02:05
I've used Loctite successfully. There are 2 kinds, which differ in how hard it is to break the bond. Unfortunately, it's been such a long time so I don't remember which type I used.
If you use Loctite, make sure it doesn't run into undesired places. I had an incident where it ran and stopped a key from opening until I took the screw out and cleaned the pieces..
|
|
Reply To Message
|
|
Author: Matt74
Date: 2016-07-18 00:22
You can try tapping the post carefully several times with a small metal object. You don't need to whack it hard, just create some vibrations. (I imagine that's what the vibrating screwdriver does.) You can also use corrosion cracker, or try freezing the part and thawing it. Don't freeze wood though it could crack.
- Matthew Simington
|
|
Reply To Message
|
|
Author: Chris P
Date: 2016-07-18 01:55
Or if possible, remove the pillar and apply some key oil and heat it up, apply more oil and repeat until the screw is freed up.
I had a Yamaha YAS-82ZUL alto sax where the LH3 and high E screws were absolutely frozen solid in their pillar heads. Fortunately it was an unlacquered alto as I had to use a fair amount of heat to free the screws (Yamaha Custom series saxes have stainless steel point screws without the nylon lock). The screw slots did sustain damage, but that was easily rectified by recutting the slots, and filing, papering up and burnishing the heads so they were looking good again.
On rod screws, they're more likely to rust and bind in the key barrels but the threads will often remain free to move, so they will still operate, but you probably won't be able to extract the rod screw successfully without damaging the slot. So on really rusted up rod screws, the only way to remove them is to cut through them where the key barrel meets the pillar head and remove the key, then punch the key rod out from the barrel (also apply some penetrating oil and heat to help free the rusted screw). The screw thread can be unscrewed and the head can be punched out from the pillar. Replace it with a stainless steel screw if possible. The key barrel may need to be swaged so it fits between the pillars.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
|
|
Reply To Message
|
|
Author: Tony F
Date: 2016-07-18 07:23
I wasn't considering a specific tight screw here, just thinking about a generally useful tight screw tool that would be non-destructive. All the methods mentioned work, but there's always room for another tool on the bench.
Tony F.
|
|
Reply To Message
|
|
Author: Chris P
Date: 2016-07-18 07:43
Woodwind screws and especially the internal pillar threads on some are often on the delicate side, so they're more likely to strip if over torqued and that makes removal a pain.
But a well fitting screwdriver tip and a screwdriver with a long blade and decent handle will tackle the most stubborn of point screws. Will a rotational vibrating screwdriver e of much benefit if a point screw can't be undone with a conventional screwdriver?
Also the thing with electrical tools and power tools is the batteries are often drained if they've been sat disused for some time - a traditional screwdriver won't have that problem.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
|
|
Reply To Message
|
|
Author: Tony F
Date: 2016-07-18 13:59
Hi Chris,
You're absolutely right that the right screwdriver used properly will mostly do the job, but I have come across screws that would not yield to this approach. The original tool, as I frequently witnessed, would move screws that did not yield to any other method, be it force, heat, oil, whatever. What is more, it did it without any chance of damage. At the moment I have one hand in plaster, but when I get it back I'll research this further and see how practical it is. I take your point about batteries, but that's the nature of such tools and we must live with it.
Tony F.
|
|
Reply To Message
|
|
Author: Chris P
Date: 2016-07-18 14:27
An ultrasonic screwdriver is more feasible than a sonic screwdriver.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
|
|
Reply To Message
|
|
Author: shmuelyosef
Date: 2017-08-27 23:14
A couple of points (pun intended)
There is a product for providing reversible friction on headless pivot screws...Loctite 222. It's difficult to find in hardware stores but readi,y available online. It's designed for set screws and adjusting screws.
I'm also curious how much effort people pu into shaping screwdriver blades for applications...e.g. the very narrow slots in clari et rod screws. My Wihas don't go all the way in.
|
|
Reply To Message
|
|
The Clarinet Pages
|
 |
.jpg){kind=small}
.jpg){kind=small}
.jpg){kind=small}
.jpg){kind=small}
.jpg){kind=small}
.jpg){kind=small}
