 The Clarinet BBoard
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Author: CaptForce
Date: 2017-06-28 01:32
As the new owner of my R13 Greenline I concerned with the best of care. I have lost the screw at the bottom end of my A/D ring key. These fasteners are so small and difficult for me to discern thread characteristics. Can I use one of the screws of the same position on my LeBlanc Noblet as a replacement without damage from a different thread size?
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Author: Steven Ocone
Date: 2017-06-28 02:18
These screws have a nylon (or some other material) ring close to the head which secures the screw. The screw is not meant to be seated, but turned in just enough so there is no excess play. I guess your ring wasn't very tight. It is best to get a replacement. Until you do, I would replace it with screw at the top of the F/C lever which is less critical. You can carefully try your Leblanc screw for the F/C key. I've even used a toothpick in an emergency. I believe it is a 2 mm x .4 mm thread
Steve Ocone
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Author: CaptForce
Date: 2017-06-28 23:09
Thanks, Steven, for your excellent advice. I noticed that the fully seated screw from my Noblet caused a delay in the action of the key. I have the right fastener with the nylon collar in place now and all is well.
I'm new to this forum and finding it very valuable.
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Author: Caroline Smale
Date: 2017-06-29 00:10
In general most manufacturers use very specific point screws on their instruments and it is highly unlikely that a screw from one make will accurately fit a different make.
There is also a risk of damaging the thread in the post by forcing in the wrong screw.
Most professional clarinets have their point screws individually adjusted to fit just the one precise location and although the thread would fit a different position on the same instrument, the key operation would not neccesarily be optimum.
Those nylon collar screws are a cost cheapening device to avoid Buffet having to accurately fit the screws,
.
In my opinion, such a screw, which is designed to be only partially tightened, can never have the stabilty of a properly fitted screw that is firmly tightened up to the post.
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Author: shmuelyosef
Date: 2017-06-29 06:29
Caroline,
I entirely agree with you. These used to be precision turned screws with flat heads that seated into the posts precisely. The adjustment was done by either gently reaming the flat inside the post (typically just 1 or 2 mils) to tighten the joint or using a taper reamer to increase the depth of the conical recess in the rod to loosen. Most high quality saxophones and some (preferred by me) high quality clarinets still use this method.
For the ones where you just 'snug it down', I have used thread locking compound labeled temporary or "light", i.e. NOT permanent, to create a slight binding in the threads that acts as a cheap lock...not as good as a tightened fit, but better than a piece of plastic.
I remember that H.N. White (the venerable american manufacturer that made the King saxophones and clarinets...including the famous Super 20) used a variable position headless screw with a locking nut on it. It worked very well and these instruments were a joy to fine tune...no reaming, but when you were done, it was for a long time perfect.
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Author: Chris P
Date: 2017-06-29 10:53
I hate these screws with a passion and they're a recipe for disaster. There are no other screws that will fit, short of bushing the pillar and fitting a normal point screw with the full length thread and fitting it properly so when screwed in, the key is pivoting between the points with no end play nor binding.
The main problem with these screws is there are hardly any screw threads remaining in the pillar as the countersink is very deep, so the screws are barely held in.
Bad move, Buffet. But it seems like they're here for the duration whether we like it or not.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: CaptForce
Date: 2017-06-29 18:59
Why would it be improper to employ a drop of chemical threadlocker such as the blue (non-permanent) Locktite? This product is commonly used in threaded metal to metal contact to ensure that threads remain secure among moving or vibrating parts as within aircraft components. A tiny amount applied with a needle to the threads alone keep them secure and still allow replacement when necessary.
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Author: Chris P
Date: 2017-06-29 22:01
Probably as there's not much left in the way of threads to effectively lock.
The plastic collar and screw head takes up at least two thirds of the pillar head. The pillar head is only around 4mm wide at that point as one side has been faced off flat.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: CaptForce
Date: 2017-06-29 23:16
However, having few threads engaged would be the very reason why it might be best to use the chemical thread locking material.
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Author: Chris P
Date: 2017-06-29 23:50
Or ream it out, bush the pillar and fit a normal point screw.
Why do companies like Buffet and Selmer think they can rewite the book with their 'innovations' that only prove to be disastrous in practice? Stick with tried and tested methods as they will prevail instead of flogging a dead horse.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: CaptForce
Date: 2017-06-30 00:50
I must admit that reaming it out, then bush the pillar, followed by fitting a normal point screw are not within my expertise or a risk that I would apply with my meager skills; however, I can apply a small amount of thread locking material to the threads of the screw before putting it in place. So, I'm still presenting the question. Does anyone see potential harm in doing this?
I can see that the nylon collar acts as a bushing that allows the key to remain articulated and with free movement, so the thread locking material should not be bonded to the nylon. Maybe my first action should be to make sure that the Loctite (trade name) doesn't adhere to nylon. I'll test this.
I just can't accept these point screws falling out!
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Author: CaptForce
Date: 2017-06-30 01:22
I'm backing away from this entire pursuit! I had a direct discussion with someone with a background with these thread locking materials and I am convinced that I would be inviting problems with the rotation at the pin point and the nylon collar.
I think I'll just need to develop a habit of vigilance tending to the tightening of these screws when they first begin backing out. I just didn't have this problem with my Noblet.
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Author: Steven Ocone
Date: 2017-06-30 01:51
I have some aftermarket replacements made without a nylon collar, but I rarely make the conversion.
Steve Ocone
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Author: clarnibass
Date: 2017-06-30 10:07
>> Why would it be improper to employ a drop of chemical threadlocker such as the blue (non-permanent) Locktite?<<
It's not. It's a very good method when fitting the hinge and is not practical for any reason and sometimes good to add it regardless. For pivot screws I prefer the purple (weakest) one, not the blue (weak but stronger than purple).
>> I must admit that reaming it out, then bush the pillar, followed by fitting a normal point screw are not within my expertise or a risk that I would apply with my meager skills <<
Another issue is that very few would be willing to pay to have that done, considering the result (as far as playing) is basically the same. It is the best method but Loctite usually works just as well for a very long time (years).
>> I'm backing away from this entire pursuit! I had a direct discussion with someone with a background with these thread locking materials and I am convinced that I would be inviting problems with the rotation at the pin point and the nylon collar. <<
I disagree. Loctite is meant for metal, but in this situation there is metal contact in the threads. Loctite could possibly damage some plastics... but not sure if it would damage nylon (see more later). BTW is the material definitely nylon on those screws?
There are a few theoretical problems with Loctite.
First, you sometimes need to reapply it if you remove the screw. Maybe surprisingly... not always! Sometimes even if it stops gluing, it keeps enough friction to be reliable. Anyway this adds a few seconds.
Second, for a loose metal screw, if you use Loctite to lock it, then until the Loctite dries the screw would be loose. I use this method only if time/budget doesn't allow a better method but from experience I found that it doesn't cause any problems. I consider blue Loctite in this case, maybe for larger screws (I would rather fit the hinge).
For those buffet screws it's not an issue since the plastic keeps them in place anyway during this.
Third, Loctite can damage plastic... in theory. As a test, I tried Loctite on plastic/nylon screws (not a sleeve, the whole screw). It didn't seem to cause a problem and damage the screw. What was a bit of a problem is it held as well as metal pretty much, but the head of the plastic/nylon screw is much less resistant to the screwdriver, so could be too strong. So I'm not 100% decided on this method for loose plastic/nylon screws, leaning slightly against it for now.
However with the Buffet screws it is just the sleeve, experience shows there is no damage, there are metal threads on both sides, no reason not to use Loctite.
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Author: CaptForce
Date: 2017-07-01 03:52
OK, I'll keep the purple as an option if my vigilance isn't sufficient to keep up with any movement of this screw.
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Author: dorjepismo ★2017
Date: 2017-07-01 07:37
Chris P,
"Why do companies like Buffet and Selmer think they can rewite the book with their 'innovations' that only prove to be disastrous in practice?"
As a programmer, I'm familiar with the self-destructive Will to Tinker, but as a musician, I'd prefer that my instrument just work correctly. There is good and bad in the B&H 1010s, but one of the best things they did, as long as one can keep from doing a Donald Trump handshake on one's lower joint, is to eliminate pivot screws.
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Author: clarnibass
Date: 2017-07-01 08:29
>> one of the best things they did, as long as one can keep from doing a Donald Trump handshake on one's lower joint, is to eliminate pivot screws. <<
There are ups and downs but overall pivot screws are a better method for the longer hinges.
Post Edited (2017-07-01 13:00)
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