I recently purchased a DIY music box kit from a website which I will not link to here. If you watch this video you can see that it has a serious design flaw: it has a tiny hand-crank, and it's thus next to impossible to play your custom tunes at a constant rate. The thing sounds like crap for this reason alone.
I'd like to automate the crank with an electric motor, since I am under the impression that it's pretty hard to make your own wind-up music box (difficult to get the wind-up mechanism to turn at a constant rate, involves fans and other intricate timing mechanisms, etc).
So it doesn't take much torque to turn the crank, but it needs to be turned approximately 100-150 times per minute in order for the music to sound decent. What kind of motor am I looking for? It should be relatively small, so I can fit it in the wooden music box I'm making along with the musical mechanism itself and whatever other contraptions I need to put it all together. I'm also pretty noob with electronics, so I'd prefer not having to put together my own circuit board or anything; at most I'd like to just make a few solders and hook up the battery, then snap on a few widgets & gears and pump out those tunes.
What kind of motor should I use?