Measuring torque curve...

[[XAP]Bob]

Is there an easy(ish) way of measuring the torque curve of a hub motor?

Someone elsewhere has asked if I know what it looks like, but I can only say what it feels like at the moment. Be interesting to know if there is any sane way of measuring the torque at different speeds?

 

[Deleted member 4366]

Torque is directly proportional to current in a DC motor, so you can use an ammeter or wattmeter. The motor tries to take maximum current at zero RPM and zero current at maximum RPM. Between the two, the curve is nearly a straight line; however, the controller limits the current, so the curve is flat at say 15A until the curve reaches less than 15A when it ramps down to zero.