Motor and controller specs help for a complete tyro

Hi to all, and thanks to anyone who is willing to help out a complete ignoramus here. I am not building a robot, but rather a coffee roaster. After spending hours hunting for an appropriate motor and controller combination to run it, I figured that robots would use identical technology.

I want to drive a drum style roaster, with a radius of rotation of 5 inches (12.7 cm), and a mass of 10 lb (4.5 kg). The coffee load will be a maximum of 4.4 lb (2 kg), likely at the limit of rotation as well, so a total load of 14.4 lb (6.5 kg). My extremely rudimentary math says that would mean a minimum torque of 8 Nm. Does that seem correct?

Second question, what type of controller would be most appropriate for this purpose, variable speed, max rpm’s of 120, reversible motor. I’m guessing that the most likely motor for the application would be a 12 or 24 VDC motor.

I deeply appreciate any assistance.


Tim Blackmore

hello blackmot,
didn’t understand your question very well but I will try to help,
my opinion is to go with an Arduino because it is easy and cheap.
but the thing is that controller will not vary the speed or the rpm, so you need to buy a motor driver that can handle the motor specs.
you need to be sure that the motor driver has a PWM(to vary the speed), and an H-Bridge (reverse direction)
sorry if I didn’t answer your question.

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