A bit more info on Autotune. It is used in Mods where the Motor Specs aren't readily available. The fields are energized and the motor Armature is is held at zero speed. When the M switch is pulled in for a second or two, no Motor rotation should occur. The Inductance of the Motor is then measured. Using these measurements changes are made to various Drive Parameters. As I said in the previous post. It worked better in theory, than in real life.