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 Need professional advice re: key cork
Author: m1964 
Date:   2018-11-03 18:50


Hi,
I need an advice of a professional repair technician.

My R13 had a little "gap" between the top of the left pinky F/C lever and the bottom of lever at the back of the right pinky F/C key, so when I used left pinky to push F/C key, I felt there was too much travel.

I was not sure what would be a better fix: I could either raise the left pinky lever by replacing the cork under it or replace the cork on the right pinky key with the thicker one.

I chose to do the later: I removed old cork at the bottom of the lever at the back of the right F/C key and glued new cork, slightly thicker and then fine-adjusted the fit with sand paper.

However, now I feel that I maybe should not have removed that old cork. The old cork was too thin but it was hard so pressing the left key produced "immediate" action as soon as the key traveled beyond the gap.

Now, when I press the key I get a "spongy" feeling possibly because the new cork is thicker and softer.

Can anyone suggest where what would be the best way to fix this small problem?

I noted that JLSmith sells sheet felt in different thicknesses but the price is $42 for a set is a little too much because I only need a tiny piece of the material...and I am not sure that felt would be hard enough.

I am not a professional technician but I used to play professionally and always did basic maintenance and even small repairs by myself. Now I play in local community band and in an amateur symphony orchestra so the little problem like the one above have no practical bearing except that I like my instruments to be in top shape.

Thanks a lot for your help.



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 Re: Need professional advice re: key cork
Author: Steven Ocone 
Date:   2018-11-03 22:29

I usually use a material called tech cork or gummi cork in this area. It has cork pieces in a binder and is very firm. There are other materials that might fit the bill. Sometimes I put a thin layer of Teflon over whatever is not thick enough. Since you have some repair skills, you can experiment.

Steve Ocone


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 Re: Need professional advice re: key cork
Author: Caroline Smale 
Date:   2018-11-04 02:29

For the best possible response in the LH F/C action the actuating arm should be as nearly parallel as possible to the rear surface of the F/C key, and the gap between them as small as possible.
To achieve this it is sometimes necessary to add a very hard material to the mechanism, I often soldered a very thin brass shim to either the upper or lower surface and then filled the remaining very small gap with thin Teflon (0.005 or 0.010") or even leather (from an old sax pad for instance).
This results in a really firm and snappy response to the LH F/C operation.

Many brand new professional clarinets I have had in my workshop have needed this treatment.



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 Re: Need professional advice re: key cork
Author: m1964 
Date:   2018-11-04 03:32

Caroline Smale wrote:

> For the best possible response in the LH F/C action the
> actuating arm should be as nearly parallel as possible to the
> rear surface of the F/C key, and the gap between them as small
> as possible.
> To achieve this it is sometimes necessary to add a very hard
> material to the mechanism, I often soldered a very thin brass
> shim to either the upper or lower surface and then filled the
> remaining very small gap with thin Teflon (0.005 or 0.010") or
> even leather (from an old sax pad for instance).
> This results in a really firm and snappy response to the LH F/C
> operation.
>
> Many brand new professional clarinets I have had in my workshop
> have needed this treatment.
>

Steven and Caroline,

Thanks a lot for replying to me -the surfaces are parallel and the gap between is about 1-1.5 mm.
I like the idea of using leather instead of cork.

Many yesrs ago, I had to do the shim repair on my old French stencil clarinet because the activating arm was rounded. I had to solder a piece of metal to make it straight, otherwise it would just jam. Plus reinforcing multiple lose posts.

Remembering those things makes me appreciate even more when I play the R13 which I could not afford back then.

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 Re: Need professional advice re: key cork
Author: shmuelyosef 
Date:   2018-11-04 05:14

I generally apply a very thin piece of tech-cork (I get mine from MusicMedic) to the 'tang' that hangs off the actual key (with the RH touch and pad). This is a straight, flat section. I used to use leather, but the tech cork is harder, thinner, and wears better. Note that the contact point on the LH key is a rounded surface...i.e. a "cam"; it absolutely MUST be level with the RH touch contact point, and for best response, should have a constant radius and a polished surface. I find that many clarinets original equipment have a badly finished surface that contacts first at one edge...the contact should be a line square with the parts. Once you get this set up, you can apply a piece of bumper cork on the bottom of the cam part to take up the lost motion. This should never get compressed so it is not a critical material.

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 Re: Need professional advice re: key cork
Author: clarnibass 
Date:   2018-11-04 11:39

>> For the best possible response in the LH F/C action the actuating arm should be as nearly parallel as possible <<

The ideal shape for this linkage is like involute gear teeth, but it's usually unrealistic to change them after the fact and really should be designed and made by the manufacturer to that shape. I think Selmer has made some clarinet with that shape... if I remember...

So making them parallel is the next best option, but because of the soft materials (even relatively firm ones), there is no real precision in the mating surface (even though there is a precision feel), so best to make sure the outer end of the lever side linkage arm is touching (i.e. leaning to that end in the slightly not completely parallel way that it has to be).

>> To achieve this it is sometimes necessary to add a very hard material to the mechanism, I often soldered a very thin brass shim to either the upper or lower surface and then filled the remaining very small gap with thin Teflon (0.005 or 0.010") or even leather (from an old sax pad for instance). <<

Exactly what I sometimes do too. I use silver or nickel-silver but that's just a cosmetic difference.

>> Thanks a lot for replying to me -the surfaces are parallel and the gap between is about 1-1.5 mm. <<

Is that just a very rough guesstimate? That's a huge gap for that linkage. I prefer not to use thicker than 0.5mm material there (meaning the gap has to be no more than that), or even 0.2mm-0.4mm optimally.
On many clarinets that linkage has such a bad shape that it's a bit more of a compromise without doing significantly more work.

>> Remembering those things makes me appreciate even more when I play the R13 <<

I've seen R13s where this linkage was just terrible, basically a sharp angle between the parts, as if it was soldered at an incorrect angle.
More recently Buffet started adding an adjustment screw there, which is a good idea in theory, but it is positioned so the lever arm is so short, increasing travel.

Another issue (common on R13s and many other clarinets) is that the edge of the lever side is relatively sharp. This digs into whatever material you use and squishes it or even tears it. It's worse the thicker the material is. This corner should be rounded, but rounding it too much would increase travel of the lever significantly because of the angle change when pressing it.

>> I used to use leather, but the tech cork is harder, thinner, and wears better. <<

Tech cork isn't really thinner than leather, it is available in many thicknesses, just like leather. I stock tech cork from 0.3mm to about 3.0mm and pad leather is usually not much thicker than the thinnest tech cork.
I often use a synthetic leather material that is similar to leather, about 0.2mm-0.3mm thick, and is tougher than excellent quality pad leather.

If the gap is 1.0mm-1.5mm when the linkage arms are parallel, then first check that the F/C key is opening enough. If not, it is usually stopped by the E/B and/or F#/C# keys and they might need to be opened more. This will move the outer end of the key side closer to the lever side more than the other end, so raising the lever would get it back to parallel and decrease the gap.

If none of that is an issue, I would either solder a shim like Caroline suggested or, if that is not possible for whatever reason (e.g. you want to do it yourself and can't solder) then accept the best compromise instead. Probably using a thicker but much firmer material.

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 Re: Need professional advice re: key cork
Author: Chris P 
Date:   2018-11-04 18:52

Buffet have yet to get this linkage fitted and working correctly. Both parts of the linkage should sit parallel with each other with an equal gap of around 0.5mm between them which will be taken up with that thickness of tech cork or similar hard wearing material so there's no lost motion or sponginess. All too often the LH F/C linkage is at an angle and the sharp leading edge of the linkage digs into the underside of the linkage tab on the F/C key and either binds up or chews through the silencing material. If the geometry was correct, it would work well.

But that's never the case with Buffets and is just one of many ongoing problems (for the end users and repairers) they're not going to resolve at all. They may have been fitting ab adjusting screw to this linkage on their more recent pro level clarinets, but that makes the action even worse as the adjusting screw tip is too near to the LH F/C lever key barrel instead of at the end of the linkage piece, so that makes a ton of travel in the LH F/C lever, The contact point for a clean, snappy action should be as near to the spring catch on the RH F/C key (but not fouling on the spring catch).

You'd have thought Buffet have had around 170 years to get things right instead of making things worse. For the company that gave the world the so-called 'Boehm system' clarinet (which should correctly be called the 'Klose-Buffet system'), they're not doing themselves any favours.

Former oboe finisher
Howarth of London
1998 - 2010

The opinions I express are my own.

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 Re: Need professional advice re: key cork
Author: m1964 
Date:   2018-11-05 01:29

Clarnibass wrote:
"... I would either solder a shim like Caroline suggested or, if that is not possible for whatever reason (e.g. you want to do it yourself and can't solder) then accept the best compromise instead. Probably using a thicker but much firmer material."

Thanks a lot to everyone who participated in my post.

Since I do not play professionally anymore, I followed the advice above and glued a thin piece of leather which definitely feels better than the regular cork I had there before.

Of course, it felt the best without any material at all - the left F/C key action was instantaneous without any spongy feeling at the end.



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 Re: Need professional advice re: key cork
Author: Chris P 
Date:   2018-11-05 02:41
Attachment:  P9210003.JPG (677k)
Attachment:  lhlever.png (1095k)

In the past I've resorted to using plastic cut from a Novapak reed case on this linkage on Buffets as there's that much of a gap.

Another thing that can be done if all other attempts fail is to drill into the leading edge of the LH F/C key foot (where it should make contact with the underside of the linkage piece on the RH F/C key) and fit a nylon tip in there to add extra length to the linkage piece as well as being able to take up the gap to make the action snappy. I did that recently on an E13 which resisted attempts to bend the F/C key around to reduce the gap and make it parallel. See attachment - the 2nd photo highlights the plastic tip in red.

Former oboe finisher
Howarth of London
1998 - 2010

The opinions I express are my own.

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 Re: Need professional advice re: key cork
Author: Bob Bernardo 
Date:   2018-11-05 04:26

Since you already have a new cork on take a ladies wooden nail file, available at places like Walmart and sand down the new cork. Follow the instructions of some of the techs above. Yes remove the key for best and even accurate results. Use 1500 grit sandpaper.

If you replace the cork I actually like leather pads. So take a leather pad and cut a piece of the leather off of the pad and use Contact Cement to glue it on. Leather doesn't "Give in," or wear out as cork often does. It's not spongy. It also lasts a very long time. Just a trick I learned from the past. As for the Contact Cement put the glue on one side of the leather and on the clarinet, wait a few minutes and then put the leather on. Wait about 15 minutes and you are good to go.

If you want a leather pad email me.


Designer of - Vintage 1940 Cicero Mouthpieces and the La Vecchia mouthpieces


Yamaha Artist 2015




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 Re: Need professional advice re: key cork
Author: Chris P 
Date:   2018-11-05 18:53

I have used leather in the past on oboes and cors under the adjusting screws, but find with such concentrated contact on a small area, it will compress and become noisy. I've also seen saxes where someone's used leather on the back bars of the main action and that too hardens and becomes as noisy as metal-on-metal contact, so with that I choose not to use leather at all as a silencing material.

Tech cork/rubco/gummi-kork is much better for linkages and under adjusting screws in my opinion - if you want less friction, then coat it with graphite or a layer of Teflon provided it adheres well to the tech cork. It's no good for tenon corks though - natural cork is hard to beat for tenon corks.

The only place I use natural cork on clarinets (besides cork pads) is the throat A stopper cork and also on LH Ab/Eb levers where it can be sanded to give just enough free play as well as the LH F#/C# lever on some clarinets where it too needs a tiny amount of free play to ensure the pads aren't being held open. On open standing keys I use Ultrasuede or felt to keep the mechanical noise down and a nylon tipped adjusting screw on the throat G# key adjusting screw to give fine adjustment and a better gliding action rather than using cork or anything else there. On B&H clarinets they often drill right through the throat A key arm where the flat spring screw goes, so I use rubco coated with graphite there and dome and burnish the tip of the adjusting screw to a mirror finish.

On Buffet basset horns, the LH F/C lever is a lever key like the other LH levers and is pinned to the linkage on the RH F/C key, so it is far more positive than the usual set-up found on nearly every other clarinet. I'm sure this type of lever key could be fitted to soprano clarinets and it's about time it is tried out by someone with vision instead of sticking with convention. Although I suspect going against tradition will be faced with a backlash - as per bloody usual. How are we meant to progress if convention dictates that tradition is the only way?

Former oboe finisher
Howarth of London
1998 - 2010

The opinions I express are my own.

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