Prototyping a percussion instrument, continued

With the top glued to the curved shell, I could try to tune the tongues. I started by relieving the hinge areas, which tends to lower the pitch and improve the tone at the expense of volume. I used a chisel to pare away material.

It went too easily, and I removed too much material from the hinge of several tongues. Wanting to raise their pitch, I also removed some material from the ends and edges. It worked to raise the pitch, but also made the pitch less specific and the tone more hollow. So there's a technique to avoid.

I continued to refine the sound as well as I could, and then cut a bottom from a handy piece of finish plywood, too thick to resonate well but enough for a proof of concept.

I glued the bottom to the assembly.

When the glue dried, I made a pass around the bottom with a flush-trimming router bit to bring it in line with the shell, and then played it a bit with superball mallets.

So how does it sound? Well, promising at best. I plan to make another at some point and correct these problems:

• Tune and free the hinges cautiously, and avoid trimming the ends or edges of the tongues.
• Make a shell that resonates. The kerfed sides of this one are effective sound-deadeners.
• Use a thin, solid back that can resonate.

When I make those improvements, it will be easier to tell whether this is a dead end or a promising direction. I'm still interested to find out.