[kumarak]

I would like to rebuild/replace the existing key feet cork which are in round shape for lower stack keys. Can someone suggest how to replace such corks? and if something readily available in the same measurement?

Current Measurements using caliper are:

Key Feet Outer Diameter = 8.01 mm
Key Cork Diameter = 7.22 mm (north/south), 7.50 mm (east/west)

Thanks for your attention.

 

[skeller047]

You have 2 options. One - buy cork pads. Music Medic sells 7.5mm pads. Cork Pads

Two - buy (or make) a 7.5mm punch, and punch disks out of thick sheet cork. Also at Music Medic. I think you could find a punch at a leather craft store.

Of course, if you have a steady hand, you can try to carve the feet out of sheet cork, or a wine cork.

 

[Hassles]

Kumarak - You will find this video linked below to be beneficial.....

 

[kumarak]

You have 2 options. One - buy cork pads. Music Medic sells 7.5mm pads. Cork Pads

Two - buy (or make) a 7.5mm punch, and punch disks out of thick sheet cork. Also at Music Medic. I think you could find a punch at a leather craft store.

Of course, if you have a steady hand, you can try to carve the feet out of sheet cork, or a wine cork.

Thank you so much for your insightful comment and taking time to respond.

 

[kumarak]

Kumarak - You will find this video linked below to be beneficial.....

Thanks! for sharing the video.

 

[Hassles]

Rennsteig Werkzeuge GmbH: Products

www.rennsteig.com

 

[PigSquealer]

@kumarak why exactly are you changing the cork feet ? You do realize this will change the key heights and tuning. The one you pictured is not bad necessarily.

 

[kumarak]

@kumarak why exactly are you changing the cork feet ? You do realize this will change the key heights and tuning. The one you pictured is not bad necessarily.

Yes, I do understand the relationship between the key height and tuning. This cork is 50 years old and was never changed. It's very hard and feels like a stone on touching and it doesn't seem to be consistent if you see in pics the back of the cork is crooked. Shouldn't that be round and consistent from all sides? If I don't change the cork, then I have to put extra adjustment material on both body and on the cork to compensate. - I'm not an expert, but would welcome some suggestions on the alternatives and I'm keen on learning this stuff in terms of best practice. Thanks for taking interest in the post/topic.

 

[milandro]

the shape of the cork is not the problem, the hardness may be (only if makes any noticeable sound) you are very likely to mess up the entire horn unlss you know what you are doing and you don’t seem to from the way you say things.
Don’t get hung up on symmetry

 

[saxoclese]

It is a common practice after regulation in the lower stack to sand one or more of the feet cork to remove "lost motion". This can be done by pulling a strip of sandpaper between the body and cork with light pressure on the foot of the key. I use 400 - 600 grit wet or dry. Since a new cork rarely fits flush with the body, the shape shown in the photograph is not uncommon after sanding. The cork pads from Music Medic are just 3mm thick and might have enough protrusion to work. They will still need some sanding to remove lost motion. In any event, what I have used for years under lower stack feet to absorb any bounce and to quiet the action are self stick felt pads. They stay in place and when removed leave no mark or adhesive. If they are a bit thicker than needed I use a hammer and a steel block to compress the felt.

 

[PigSquealer]

@kumarak leave the cork alone. The cork feet were sanded as part of tuning process. Hard by what standards? Looks like multiple layers glued together to achieve the needed thickness. That laminating process can give the feeling the cork is hard.

Clean the tubes & rods well and reassemble the unit. You will probably notice a lot of mechanical noise reduction just from oiling. Get that loose felt cared for.

If you don’t get the noise reduction you’re looking for. Now measure the opening height of each key. Write measurement notes. Then change the corks. Sand some but not to full opening. Test play, check tuning for being in tune within itself and to a good tuner. Sand / adjust repeat.
Good luck !

 

[stevesklar]

If you want to cut your own cork just search for "leather hole punch set" and those individual tools are what you want to cut your own cork pads on any thickness cork sheets. make sure you use a soft plastic cutting board or some material underneath for cutting.

 

[1saxman]

You can buy cork 'stoppers' at the hardware store in different sizes. Its a round, tapered cork that you cut to the length/diameter you want. You save the cuttings too because you can use a smaller one under the G# key and really tiny ones in the G#/bis adjusting screws. In the lower stack, a round felt is glued to the body under each cork foot to suppress key bounce. So with new soft cork and the felt, your keys shouldn't bounce.
Yes, you have to adjust the key heights by sanding as mentioned above but normally you never end up with a crazy mess like you have. Take off the clothes guard when doing this job and be sure to pull the sandpaper straight out - and make sure its one-sided sandpaper and you have it turned correctly.
What you do about the felt is to remove the old felt and any adhesive residue, then use a strip of the felt you're going to use for the round bumpers as a gauge before sanding anything just to make sure you need to, and during sanding to prevent taking off too much. 10mm is a good gap on the lower stack but that gap should be tapered as the bore increases.

 

[PigSquealer]

I was thinking how I would make a quick DIY punch.
You need a piece of 3/8 hard tube. Messy but you could probably cut one end off an old sharpie. Measure the inside diameter. That will be your finish size rough.
Should last long enough to make a dozen. The pictures below were made from a syringe body. Total time was less than five minutes.
Find the material.
Mount a drill motor in bench vise. 1/2” chuck
With a fine file I squared the end. Then file the bevel for the cutting edge.
Neck cork on firm surface gently press and rotate the tool until it cuts clean. Part done.
cost….about zero for tool.
glue the two together, sand to finish size or find a smaller tube. Your chances are better cutting thinner layers. The cork will split using this technique trying to cut a thick piece. Or you need thin wall metal tubing. I’ve made plenty of those.

also cover the opposite end so you don’t cut your hand !

 

[Hassles]

oh jeez - the OP is gonna' have mental over-load and may never return ;-)

 

[stevesklar]

oh jeez - the OP is gonna' have mental over-load and may never return ;-)

Yup, all OP needs is a punch set like the one attached. Then you can make circular things from Cork, Leather, Felt, linoleum, hamburger. For cork I just use my hand to push and rotate it down to cut.

 

[Hassles]

Yup, all OP needs is a punch set like the one attached. Then you can make circular things from Cork, Leather, Felt, linoleum, hamburger. For cork I just use my hand to push and rotate it down to cut.

View attachment 119125

yep - ideal - OR - post #6