2026-03-25

Last modified: 2026-03-25 10:41:07

Keyboard Glockenspiel

Check out the mechanism in a "toy piano": https://www.youtube.com/watch?v=4GAB_MafIxU&t=40s

Only 2 parts! The key part pushes against the hammer part, and the hammer velocity is increased just by leverage, rather than by storing energy in a spring or passing a detent or anything.

So I reckon that would be viable for my keyboard glockenspiel, except I would rather have some damping (but probably easy to add damping without increasing the part count, e.g. have the back end of the hammer do the damping.

But given that this exists, a compliant mechanism that needs a screw and 2 magnets and a separate part for the damper is not really winning anything.

So what if we're more ambitious? A compliant mechanism that doesn't need the screw or the magnets, and includes a damper? So just one part that you peel off the printer and put in the piano and it works straight away.

So the core of this would be like a bistable mechanism for the hammer, except that it doesn't want to actually be bistable, it wants to click over like a bistable mechanism would, to fling the hammer, but still have enough restoring force to reset on its own when the key is released.

So I think start with that, and then based on what I end up with, see where would be a convenient place to put the damper mechanism.

Something like this?

I feel that perhaps the right-hand flexure going to the hammer ought to be thicker than the left-hand one. And perhaps the key pivot needs more stiffness, as that is where the restoring force is coming from. But I'll just print it and try it.