I have to turn something at a relatively slow, constant 7.5 ish RPM for long periods of time (1 hour at a time) and was wondering something. Obviously I'm using a geared DC motor, but most of them only go down to about 30 RPM or slightly lower. (Except for the one motor with a 1000:1 gearbox I can find)
Anyway, my question is this. Is it better to use gearing or an H-Bridge to slow it down even more? The project already has an MCU, so adding an H-Bridge wouldn't be hard.
If gearing is the answer (which is suspect it might be), what would be better for very quiet operation, spur gears or timing belts with pulleys? I know straight cut gears aren't usually the quietest things in the world (have you ever heard a racecar transmission), but does the added complication of the belts provide noticeable sound dampening at such low speeds?
Hm, it seems like it'd just be easier to buy the higher ratio gearbox instead of trying to mess with either.... (But the reason I'm asking is because that motor/gearbox is more expensive.) But with the added costs of the gears.... dangit why do I always work out my questions when I'm typing up a topic.... Anyway, I would still like to know which is quieter.