This is an idea that I can’t get out of my head, so I’m going to get it down here.
Then either it gets torn apart, sinks without trace, or I get all the help I’m going to need to even think about pulling this off
First, if you google “Robot Drummer” you get things like this:
which is fun to look at but it’s trying too hard to emulate a human drummer. As a result it’s over complicated and the movement is sloppy, leading to horrible timing.
What I want to do is drive a small contact point onto a drum/cymbal/paint bucket/saucepan, hard and with reliably accurate timing (ie. ±1ms from when I want it to happen). More like the rhythm section of a fairground organ.
I want it to play hard, fast music that would ordinarily come out of an electronic drum machine. I imagine adding all sorts of other non-drum instruments to it. The whole thing would be controlled by MIDI and would effectively allow the “acoustic” performance of techno. Kinda like this, but without the human in the loop:
(Note that a lot of what sounds like complexity in this performance is just the “drums” rattling around on the floor!)
There are many problem spaces here.
Power Source - Electric or compressed air? Electric is more portable and cheaper to connect. Compressed air is more versatile, especially when thinking of things that spin or expell air (air-raid sirens, organ pipes etc.)
Mechanical design - What moves? Drumstick on a pivot? Linear impactor “gun”? BB gun? Linear actuators or rotating?
Duty cycle - For some instruments I’d like to play at least 8ths of a beat at 180bpm which is ~40ms between hits. How soon after playing one shot can you play another? This is a function of impactor speed, travel distance, mass and actuator power. Multiple impactors per instrument is fine. After all, drummers have two hands and double bass pedals are a thing.
Control & Calibration - A small computer receives a MIDI signal. An exact number of ms later, the impactor must hit. This will differ due to variations in impactor mass/material and actuator power. Would be great if was auto-tuning and could listen for the impact transient.
Expressiveness - Can I control the volume/tone of a hit?
Moving Target - Hitting things moves them, sometimes by a lot. A human drummer can compensate, a robot drummer cannot. Hey that rhymes. Either the movement is detected and the timing adjusted, or the actuator moves with the instrument, or the instrument is prevented from moving too much.
If I can get kick/snare/hat working I’d call that a success tbh