Mark,
For rough ballpark: assume load moment of inertia of a 3 pound 6" dia uniform disk. Assume CIM shaft coupled directly to wheel. 5300 RPM free speed, 343 ounce-inches stall torque, linear. At setpoint of 4000 RPM, tune so decel (motor command = 0) is 1/3(?) of accel (motor command = 1).
Controller:
bang-bang needs no explanation.
TakeBackHalf can be found
here.