[antoniodrums]

I have a CNC Roctech Router machine. For operating the machine I use Richauto controller DSP A11.
Recently I have some problems with the machine. It does not work properly on X axis. I exchanged the servo motor on X axis and all the cables, but it did not solve the problem.
When I start the machine to work according to the assigned program, there are distortions on x axis. When the machine finishes the assigned program and comes back to 0 position, DSP controller shows all 0,000 but the machine does not come to 0 position on X axes, it is 20 mm of track.
Can you diagnose what is the problem and advise me what to do?

[he1957]

If no settings have been changed sounds like your machine is losing steps. You don't mention if the 20 mm is + or - off zero.

With the DSP, select the "Distance" mode and move the axis by a measurable distance and measure it to see if the moved distance is correct. Repeat in + and - directions multiple times to see if the distances are random or consistent.

WARNING: In distance mode, the limits are not checked!!! Be really careful if you accidentally tell Z to move by an out-of-bound distance!!!

If consistent could be a setting that's different.

If they are random, it's probably missing steps, could be due to binding or some other most likely mechanical problem. Loose motor mounts, pullies, belts etc.

You could try swapping the motor drive connectors (X and Y) to see if the problem moves to the other axis to get another idea where to look for possible problems.

You mention servos, so check for dirt/dust in encoders, loose wires, bad solder joints or loose connectors etc.

Could also be a bad cable between DSP and motion control card. You could try re-seating both ends.