Hi, first post here hope this it the right place.
I’m not making a robot (as much as I’d like to!) but need a motor to use as a generator in a proof of concept application.
I’ll be converting a short (~7mm) linear motion into a rotary motion by basically attaching a pulley/disc/lever (I’ll check the rest of the store later to see what’s here) to the shaft of the motor and pulling on it, so think crankshaft and one piston stroke in an internal combustion engine terms.
I expect to get 30 to 60 degrees of rotation, depending on where I place my pivot point and the linear motion will take 0.2 seconds, thus rotation speed is 25 to 50 RPM, so this is one criterion for the motor.
Having used some basic trigonometry my effective lever length will be ~13 to ~7 mm and my pull force will be an average of 3.25Kg, giving an average torque of 4.3kgfcm (60ozin) to 2.5kgfcm (35ozin)
Note, the figures are arranged in RPM order.
Power at input shaft will be about 1.2 watt
So, I believe i need a motor rated at about, taking mid values, 37 RPM, 3kgfcm/42ozin, 1.2 watt. Preferably DC brushed, encoded would be handy not not essential.
These looks close
I assume all the specs such as output, speed, torque are at the final output of the gearbox, not just the motor. The efficiency figures seen very low (20/30%), is this due to the gearbox.
I just looked in this category:
https://www.robotshop.com/eu/en/gear-motors-with-back-shaft.html
Thank you!