Laser: Slipping position

[tellblom]

I never notised before when doing my wood stuff but when i attached the laser and is cutting i can se that the postions slides some times. I can do small thing without it slipping, but when I do long runs and bigger it seems like it happens.
It seems like it's like 0.3mm it slips.

I have tried adjusting the tension on the belts but I still get this

Any suggestions on what can be done?

[mstrens]

Perhaps a pulley that is not completely fixed.
Check the blocking screws

[tellblom]

Perhaps a pulley that is not completely fixed.
Check the blocking screws

Thanks for the suggestion, I have tried to tighten them but they are solid as a rock.
What I can feel when I hold the small pulley on the X and move thje stepper motor (by hand) I can't feel any wiggeling in either of the three pulleys, so I hope that they are tight.

I have to further investigate to see more when it happens since it's not happening all the time

[mstrens]

Perhaps you are moving to fast and steppers are loosing steps?

[tellblom]

I run 250mm/min and that should work I think.

Well thanks for the ideas ... I'll will write down speeds next time it happens