# Calculating Minimum Gear Ratio To Lift Weight

I have a 337 watt motor, and want to lift ten pounds. What kind of gear ratio will I need for a gearbox I attach to this in order to lift the ten pounds at a constant speed?

• We need to know quite a bit more than this to answer the question? – joojaa Jan 15 at 5:17

Given motor RPM $$\omega$$ (in RPM) and assuming radius of gear coupled to its shaft ('input') $$r_1 = 1$$, you have $$2 \pi \omega_1$$ of linear speed of the gear's teeth. For the desired output's linear speed to be 7.64 m/s, or 458.4 m/minute, $$v = {458.4 \over {2 \pi \omega}}$$ or about 73/$$\omega$$ - where $$\omega$$ is your motor's RPM.