I wonder if direct rotation drive is feasible? You can get a lot of power out of a motor, and as much throw as you want! Also, the force is constant, unlike with a solenoid, which varies as the bolt is surrounded by less coil.
We need angular acceleration for this. Moments of inertia. My A-levels feel very long ago…
Let’s model the drumstick as a simple rod with the axis at one end. 0.5m long, 0.05kg in mass
So:
People who know about this sort of thing: There’s no way I can generate that much torque from a standing start in just a few milliseconds is there?
I suppose you could have a continuously rotating drive with a flywheel, and some sort of trigger mechanism that engages the drumstick when a hit is required. Potentially, you’d only need one motor for the whole machine, if you lined up the instruments along a common shaft.
Further thoughts:
The “triggers” could be part of the rotating drive, like the pins on a music box cylinder. But instead of putting a pin where you want a note, you just engaged the instrument. That would guarantee perfect synchronised timing, for free, assuming you can maintain a constant rpm (or you can feedback a reading of the rpm and use it to drive the bpm of the sequencer
It’d look cool too.