Motors

[oliveguardian]

Hello all, I'm new user on adafruit, but a long time costumer/tinker and frequently make looks that incorporate spinning motors into headgear and accessories. When I first started, I would poach motors from children's toys. Lately I've been trying to get more into using my own motors, but an issue I've add is that the very small motors I've been able to find spin at a very very high rate of speed. You can slow them with gear steps, but that can be tricky to pull off custom. Hoping someone can recommend a higher torque, slower turning battery op motor like would be used in a toy ferris wheel or carousel so I don't have to build the gear stops myself. Think of something that would be able to turn the carousel on the head of a Beetlejuice costume, as an example. I've found plenty of toys with motors that seem to work, but struggled with custom motors. Any help is useful. Thank you!

[diaphone]

Small DC motors are readily available with just about every imaginable combination of gearbox and reduction ratio pre-attached. To me, the speed of a carousel suggests you want a very large reduction ratio, which is probably best served by a motor with an integrated right-angle worm-gear drive. Worm gear reduction is generally quieter than in-line spur gears and planetary gearboxes, and has the extra advantage that the power transmission is one-way, i.e. you can't rotate the load by hand and cause the motor to turn at high speed, generating power back into your motor control circuitry. When the motor is off, the worm gear locks the load in place.

That said, real ferris wheels are not driven at the axle. Generally, the RPM reduction is done by having a motor turning a rubber wheel that is pressed against the outer rim of the ferris wheel itself. Since the ratio of the ferris wheel diameter to the diameter of this tire is huge, the ferris wheel turns slowly. The motor still has a gearbox or v-pulley reduction of its own, just not as much as would be needed if it were driving the wheel from the center shaft. Carousels typically use a similar setup, just horizontal. It can be a smooth track under the carousel that sits on driven tires, or it can be gear drive like this:

RingGear.jpg (19.22 KiB) Viewed 67 times

[sj_remington]

Pololu, ServoCity and others have an excellent selection of motors, gearboxes, and modern, efficient motor drivers.

https://www.pololu.com/category/22/motors-and-gearboxes
https://www.servocity.com/motors/