Yankee: There will be quite a bit of info about this little (well large) project once its done. Unfortunatly I can not give much info at this stage but it involves BEER
If i can not get the speed out of the steppers i may have to implament a 1:3 gear system and rely on the torque of the steppers instead. The think is that steppers are robust and designed to runh day in day out so for our project it will be a walk in the park for them.
for our project we really just need to ramp the motor up run it at full speed, ramp either left or right motor down and up for course corrections or if we need to do tight turns one reverse one forward.
We have several stepping modes and 1/2 step seems to provide the best torque/speed relationship but it seems that even setting the time to micros instead of mills will not do the job as it seems we are hitting some limit as we are ramping up.
Im just about to upgrade the project from the ArduPilot to the ArduPilot Mega in the hope that i can use the timers for the controll as an alternative.