It's time for another update!
Here is a photo of the data acquisition board with the new microprocessor. It runs at 4MHz, which gives a resolution of 1us on the sensor timing. The program now gathers data from all the sensors, and for 80 motor revolutions to give more information at high RPM, which makes it easier to estmate the maximum RPM via extrapolation. The toggle switch selects the correct pulse width when calibrating the ESC, and the push button starts a dyno run.
Here is the system connected to the motor and ESC. The resistor bank makes the motor spool up slower since I'm still using the Robitronics flywheel. Unfortunately, the heavier flywheel is still in limbo.
If anyone wants to machine one, let me know!
Here is a screen capture of the updated spreadsheet. In addition to expanding it to accept data for 80 revolutions from the three sensors, I also re-arranged the graphs to get velocity on the X axis. As you can see, the torque and power curves are quite smooth, with the data for the three sensors very nearly superimposed on each other. The peak power occurs at almost exactly 1/2 of the free-running speed, which is reassuring. At the moment, none of the values are scaled to any particular units.
