# Gears and rotation

I have to project a mechanism that transform a rotation of $30 \pi/\text s$ from a engine in a rotation of $(\pi/4)/\text s$.

One of the gears should be 120x bigger than the other, but this is too much.

The gears should have a ray $< 30\text{ cm}$.

How can I create this mechanism?

• Two stage reduction, worm gears, harmonics gears. There are many options. – Eric S Nov 16 '17 at 2:29
• An epicyclic reduction unit may work well... – Solar Mike Nov 16 '17 at 7:34
• A harmonic drive could do this nicely in a small package and with near zero backlash and high torque. – user6335 Nov 16 '17 at 9:18