I'm trying to chose correct stepper motors to drive 2 wheeled robot. I started with geared DC motors, but found they are too fast (I have 27:1 geared), and they provide little torque at low speed.
Therefore I'm looking at stepper motors that will give enough torque at low speed. The criteria are:
- Motors need to be small. Top are Nema 17, Nema 23 are going to be too large
- Need to be driven from low 12V accumulator
- Need to output 1Nm torque, to move 5kg dolly on potential 5 degree slope with 10cm wheels
- Need to use as less current as possible
- Need 30RPM on output shaft
I researched this topic a little and found that low inductance motors will need less volts but need more amps. As the setup doesn't require very precision movement I think I can get more torque if I go for geared stepper motors.
I found 2 identically geared motors on ebay, one having 34mH and another having inductance 2.8mH
If anyone had experience with geared stepper motors and can advice on the selection, I would really appreciate it. 27:1 is not set in stone, I can go for 5:1 if it provides enough torque, or higher if not. I can even use bare motor without gearbox, but I'm afraid it will be either too weak (even at low speed), or will have to be too large to give enough torque.