I have read a lot about the possible controller ICs over the past days.
Some futher questions:
1) The modules you suggested use use either the TCM429 or the TMC457. Does it matter which one is used?
2) My understanding is the TMC457 (beyond having many additional goodies like ChopSync, StallGard, direct encoder interface) really shines at microstepping resolution. Is that correct?
Shall I consider microstepping for my application, or does microstepping slow down the motor/reduce torque?
3) Regarding the TMC457: Looking at the parameters that can be set, I saw no mention of minimal velocity for ramp generation. On the TCM429 this seems to be the register v_min.
Isn't v_min crucial for what I am trying to do?
I thought most stepper motors can be driven with a quite high initial velocity - some vendors even say you should have a high initial velocity to avoid resonance at very low velocity.
On some early tests, using a stepper controller from another company, I was able to considerably reduce the time needed to move the 10steps by setting the motors initial velocity to 40rpm.
4) Regarding the motor duty cycle and over heating: till what temperature is it save for a stepper motor?
5) In principle, you can use the torque given in the motor data sheet to calculate a feasible acceleration / deceleration ramp by subtracting friction, and then taking into account motor inertia and estimated load inertia.
Do you have a sample formula(s) or an article which might help figure this out - I don't really know where to start.