[Gdeaver]

The original poster was looking to measure the victor- motor system behavior by measuring voltage given by a volt ohm meter vs. rpm for a given setting of the robot controller. I submit that probably is not a good measure of our robot system. If you take the battery, power distribution wiring, RC, victors and motors and try to describe it, you'll end up with a complex system of equations with many independent variables. Not nice. The formulas in the ee books are simplifications with assumptions that for many apps are good enough to approximate the motor behavior. If you notice the Bosh motor curves we where given used a very tight linear power supply. That's not the case with our robot system. I think a better measure would be to take a Typical robot setup and the Fp motor. Apply a constant load to the motor.
Set the PWM variable and measure the RPM a second or 2 latter. Then increase the PWM variable by 1, measure the rpm. After the full PWM range has been measured, Increase the load by a fixed amount and measure for PWM range. Continue increasing the load by a fixed amount and measuring until the stall load is reached. The motor should be left to cool to eliminate the thermal effects. Then plot PWM setting, load , and rpm. The surface of the plot would give a visual representation of the motor - robot performance. With the same setup thermal performance could be measured by fixing the PWM variable and the load. Then measure and plot the rpm over time.
The some analysis could be made to see if those formulas and performance curves are valid. Comments?