Early Clarinet Design
I built this using the design in Trevor Robinsons book, "Amateur Music Instrument Builder". It is based on
an early Clarinet design. It is available through the MIMF Forum bookstore.
I deviated from the design in making the tonehole keys which are mentioned below:
I've thought for quite a while on this tonehole key design and it is simple to build.
1.5" round brass Tubing 5/32" Outside Diameter.
1/2" piece of hollow brass rectangular tubing (found at hobby store) It must be wide enough for the 5/32" brass tube to be flattened out and fit inside the rectangular tubing.
Piece of piano wire. Medium gauge, need not be picky over the thickness.
Small compressible spring.
Thin solid brass rod (less than 1/8")
Cork, to cover hole.
Cut the round brass tubing to the length desired for the key. Drill a small hole that is slightly wider than the piano wire at the axis point. Drill the hole completely through the tube.
Stick the piano wire into the hole so that it sticks out on both sides. Don't trim the wire yet.
Place the tubing in a vise while holding the wire in a straight up/down horizontal direction.
Tighten the vise a crush the tubing good and flat. It should be flat enough so that the wire is held snuggly but removable with some force using pliers.
Crush the end of the tubing a little extra tight. Round the edges of the tubing end using a sander or file to your own liking
Take the rectangular piece (roughly 1/2" but may vary for your application) and drill a hole in it slightly wider than the piano wire diameter in the center of the rectangular piece of the long side (not that wide, flat side). Drill this in the center.
Using an electric sander or file, sand the (both) open ends of the wide, flat side of the rectangular tube as if you were trying to make it shorter (1/4"). Stop sanding just short of hitting the very bottom. This will leave you with wide tabs on each end. You may drill two small holes on each tab for mounting to the instrument or glue it in place with super glue gel. The super glue is a bit less authentic.
The flattened tube is used as the key. The tonehole side of it gets cork glued in place, it must also be slightly bent in order to fit the surface of the instrument well. The other end should have a small hole drilled partially into the tube, the hole should not go through the top layer. Lay a piece of brass rod in the hole and solder. Then cut off the rod so that only a stump remains there, this acts as a spring retainer so the spring won't come loose.
Drill a small pit into the body of the instrument exactly below the point there the spring retainer points down. This pit is called the "spring pit", it will keep the spring from getting away.
Cut the spring to keep good tension on the lever, don't make it too tight.
Remove the piano wire from the flattened tube and slide the tube into the rectangle. Then the piano wire will go through the holes in the rectangle and the flattened tube as well. Put the spring in place while doing this also.
Now you have a simple woodwind lever key. The key could be used on whistles and recorders. A wider rectangular piece could be used with two levers installed for 1/2 pitches and microtonal experiements.
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Written by: Daniel Bingamon 1/26/1999