What precision in the rotation do You need?
What range of RPM are You talking about?
My suggestion is to use a simple DC motor, eventually geared.
The driver handling the motor will be very simple and cheap.
Yes rpm, sorry. I was thinking bpm because I plan to figure out what voltage is required by comparing the output of the mechanism with my motor hooked up to a metronome that is going at the correct bpm. (maybe there's an easier way, but I'm thinking I could just tinker with a metronome for 5-10 minutes and get the desired result?)
Aha, beats per minute.
Running only in one direction? That makes the driver cheap.
I assume the load on the motor is constant. Then using PWM and some testing hopefully a satisfying constant can be found.
What is this project actually supposed to do?
I wrote some code where I can specify notes and note lengths, and it then generates a 3d model of a music box mechanism (or at least the part that plucks the notes) that would make the song I inputted if it is hooked up to a working comb (the thing that makes the music when plucked). So my plan is to 3d print this model and hook it up to a motor to make a music box.
Having only a little knowledge about music terminology I don't get it.
Notes I know, hole, half, quarter etc, CDEFGAH.... but I don't se the connection with the running of the motor. Please, try again..
So the model is a cylinder with spikes sticking out of it corresponding to the notes that are in the song. If I programmed the same note into the model 4 times, say 4 half notes one after the other, there would be 4 spikes in a line on the cylinder. When the cylinder rotates, the spikes will move. If I place a set of teeth that, when one is plucked, a note is played, so that it is up against the cylinder, then when these spikes move into a tooth, they will pluck it.
I am planning on hooking the motor up to the cylinder, so that the cylinder gets rotated.
The rpm of the motor needs to be regulated, because the speed of rotation of the cylinder will determine the speed at which the song I've programmed onto it is played.