I have just built the K8400 and have a problem with end-stop function.
When performing the “home” command from the operators panel for the first time the steppers continue to operate even after end-stops are reached.
The circuit boards have the red light on so power is there but the function is not. I haven’t upgraded firmware or made any alterations, the instructions on-line have been followed 100%.
Right, I ran the system with the pulleys loose and activated the sensors with a screwdriver and it worked.
The problem must then be with the alignment of the belts and pulleys even though I cannot see what since the “pins” enter the sensors.
Back to realignment of this.
I have (had) issues with this too.
This is the instruction from the assembly: https://manuals.velleman.eu/article.php?id=17
The Y belts are quite tight and I still have problems that the Y endstop can’t be reached. The motor belt starts jumping 5 mm before the stop. So I have prolonged the “pin” so that it stops a little earlier.