Gear ratio Definition and 55 Threads

Hi I have to design a gearbox for a drum, the drum should be brought uniformily to a speed of 7rpm in 8 seconds, I have choosed a motor of 715 rpm output, what's the gear ratio I should use in designing the gearbox? Thanks

I have a 8-1/2 inch drive pulley turning at 340 rpm. I want to have it drive a pulley and want that pulley, the driven pulley, to turn at 200 rpm. What is the formula to figure out what size pulley I need. Please help:smile: :smile:

I have a scooter with a 5 inch diameter wheel and I want to make it go 25mph with a motor that has this specs. ==== Power 0.35 hp @12v 1.43 hp @24v Torque 0.47 lbf*ft @12v 0.97 lbf*ft @24v Efficiency 70% @12v 76% @24v Speed 1260 RPM / Volt Voltage 12 volts or 24 volts* Weight 11...

Hi, I am doing a project that involves an electric motor that winches an object upward pulling it by a string, over a given distance and I need help to calculate an optimal gear ratio, if that is possible. This is how far I have got... Variables torque/rpm gear ratio Constants distance...

I have heard that this concept is already starting to be implimented in cars (constantly changing gear ratios), is this true?