Hi there I am pretty inexperienced with my cnc and had noticed when I sent my machine to work home that I was 5mm off of the home position. Read out said 0 and was able to move the x axis 5 mm wondering where to continue my search of the issues. Have checked for binding along the axis and there is none Have checked the belt for missing teeth or worn teeth all look good Checked belt tension seems good What else do I need to look at. Many thanks
Check and loctite the grubscrews on the pulleys. A slipping pulley does almost exactly what you describe, the flat on the motor shaft stop it slipping too far
Was this "5mm off" after you set you XYZ zero position on your work piece that day and then you had jogged somewhere?
What had happened I had set up for a pocket cut and stopped part way through because I made a mistake on depth so after I sent back to work home i adjusted g code then went to confirm on machine that everything was at 0 before I started again. And noticed that it was off. And for some reason nor quite sure why I tried moving x axis by hand and it did but only a bit and could move it back but no further. Hope that makes sense.
Seems you were dead on I pulled that stepper off tightened the 2 set screws and the play was gone thanks so much
They vibrate loose again in a few weeks. Next time it goes loose, add some loctite. I even put non permanent loctite between the pulley and the motor shafts directly.