I'm measuring the voltage directly from one of the wires of the motor. Basically, the same place that I get BEMF data for zero-crossing detection. The winding resistance of the motor is very small. Smaller than my ohmmeter is accurate to read, so I can't get a good measurement. I know there are tricks to read very small resistances, so I can get that information if necessary. No idea about the winding inductance. Is there a good method to measure that? Here's the product page for the motor I purchased:
**broken link removed**
I hooked up the motor to a commercial ESC and it spun right up to the Kv rating for the motor, so I know the motor itself is not at fault.
The Rds-on resistance of the FETs is in the 30-70mOhm range. I know that's a little high, but is that enough to reduce the max RPM by so much?