PID on a one directional Shooter

[Uberbots]

labview's PID controller is a little weird... first off set the limits to +/- 100 (for some reason this is neccesary), and scale that to the motor output (1.27x + 127)

you might want to graph the PV and PID output for this part...

secondly, push up the P gain until you get a limit cycle on the velocity (when the velocity jumps back and forth between the setpoint with about equal amplitude)
thirdly, give it small amounts of D until you see the PV settle out quickly to the setpoint when you change it/jump it.

fourthly, if it appears to never quite get to the setpoint (shouldnt happen often in a velocity controller with low load), give it some I until it appears to compensate.
Thats my [unofficial] method of tuning these PID loops... its not the right way but it works for me almost every time.

Also, if you are trying to tune with kP, kI and kD (not labview's kP, Ti, Td), keep the following in mind:
kP = kP
kI proportional to kP/Ti
Kd proportional to kP * Td