Hi, you still did not answer my question, is my stepper motor could driven faster than 100 RPM if my stepper motor details are as follows:
unipolar 24V, each winding resistance is about 25 ohm, by the way I bought the motors and did not get them from a junk.
I even used a driver chip it comes with the same result, also my CNC machine is working but some times I like to make it faster, after I tried several things with electronics of the driver and the motor it self I get nothing and I be content that it may be the screw which it's notches are very close to each others so when the motor rotate one turn the stage goes only 1mm, hope you understand my problem now.
I agree with you 3v0 also I building the diver your self will give you many options and if you did not tried that before you will not understand what I mean "shortbus= ".
what ever thanks all.