I was working on a project to make a bedside night light out of a stuffed butterfly or bird. I was making a mechanism to make the wings flap with a servo motor and some small gears. The servo motor was very loud as it moved. And this was whether or not the servo was moving large amounts, small amounts, fast or slow.
I've worked with small servos before and realized they usually are pretty noisy machines, but I can't really explain why.
Why are small servo motors noisy when they move? Is it backlash in the internal gearing?