I am currently working on a project to precisely move a XY-table using stepper motors in microstepping mode. The goal is to reach 1/16 microstepping and there is an encoder with 4000 pulses per resolution to account for missed steps.
In full-step mode the steppers work correctly, but in microstepping mode the motor steps only every n-th step, e.g. every fourth in 1/4 microstepping and every eighth in 1/8 microstepping mode. This was tested by stepping at 1Hz and observing the motor.
I expected the microsteps to be approximately equally distributed within one full step (i.e. 1/4 microstepping = 1.8° / 4 per step = 0.45° microsteps), is this a misconception? If so, what is the point of microstepping if you can still only reach full steps accurately?
Several motors of different makes where tested, with the load of the table aswell as without it, but they all show this behaviour.
Hardware used is:
Stepper Motor Controller: Texas Instruments DRV8711
Stepper Motor: Nanotec ST4118S1404-B
Pulsegeneration: STM32F446ZET
Evaluationboard: Pololu High-Power Stepper Motor Driver 36v4
Any tip is helpful, as the project is missing its point without sufficiently accurate microstepping.
Currently my guess is that the stepper-drivers circuit is faulty or it is misconfigured. To address the circuitry issue we ordered an evaluation board which we will test this week.