How to calculate engine power correctly?

Question

Electronics

Unfortunately, the mechanics are not very good, so I’ll ask for advice, there is a certain mechanism that needs to be assembled, it is a wooden gear with a diameter of about 90 cm, mounted on a shaft on a bearing on the wall, a small gear (5-10 cm) on the motor shaft is adjacent to it . You need to rotate the wheel in both directions. It is planned to take about a 50 watt motor with a gearbox of about 120 rpm. There are fears for the gearbox, if it tries to start spinning in the opposite direction during the rotation of the gear, then its mass of the gear will simply crush the trash. The question is how best to do it?

Answer 1

The task of the mechanism is simply to spin the wooden circle on the wall, and that's it??? Like for design?
Does noise matter?
If you are afraid that the drive-reducer will remember due to the inertia of the system, put a clutch for protection. When overloaded, it will begin to slip. The simplest is a screwdriver instead of a motor. It has a friction clutch (force regulator - ratchet)), and a reverse, and a speed controller are already there.