Hey Nathan,
I think I know the answer but I wanted to ask. I’m looking at our readings for current during our runs, and for our speeds we’re getting, for example, 4.25V @ 54 RPM and current of 0.17A per motor. You said the following:
If you want to estimate the efficiency curves at different voltages, you can use 12V data I shared previously to help. Note that for an ideal motor, changing the voltage will just change the y-intercept of the speed-vs-torque line (that parameter is directly proportional to the voltage). The relationship between current and torque would be independent of the voltage, as would the slope of the speed-vs-torque line.
Does this mean if I wanted to back calculate the torque based on the motor constant, speed, and current, I would use the C = 0.16+0.022T line? Or would the y-intercept be 0.16*whatever fraction of 12V we’re using? I say this because we have many low-speed trials where each motor is reading below 0.16A according to arduino. This also matches fairly well from what I’ve seen on the power supply, giving a total of 0.17A when the motors are pulling say 0.085A.
Just trying to sanity check some things. We’re now getting 50% error when I assume, say, an intercept of 0.06A and the load is only 0.17A per motor @ 54RPM and like 4.5 V.