CNC lost coordinate Z

HI all.
I have used my cnc successfully for a little time when I used hand milling tool. After that it was broken I have bought 1,5kW spindle with electric drive.

When I've started to work I've seen towards clean work (0,2 mm step on Y) that axis Z lost it's coordinate in the side out from bar)
Every 20-30 mm on Y it lost 1,5-2mm on Z.
Axis Z is horizontal. I use 2,4A stepper motors.
I have checked period jitter, it's OK. More over I have increased it much but still problem enables.

When I test axis Z in stepconfig wizard it was complittly OK with turned on electric drive (invertor).
I suspect greater weight of spindle 2,4kg. I also suspect some nuances in the main program (graphical interface) as sets of Jog.
Can anybody help me?

this sounds more like the common ' missed steps ' , chances are either your microstepping too high , or your velocity or accelleration values again are too high .

remember the higher the microstepping the lower the torque

Does the Z axis lose it's position if you are making an "air" cut?
Do you get the same problem if you take lighter and or slower cuts?

As cncbasher said you might try reducing the acceleration and velocity of the Z axis.

Also double check that your power supply is sufficient to run all axis at once.

Rick G

Thak's all. Really I have tried every thing. I reduced acceleretion and velosity to few mm.

But problem was in another - F..king screensaver of linux broke all my work.
I've turned it off and everything worked fine.