Z Axis Moves down gradually on 3D gcode

[Jcoro]

Hello everybody I have just got up and running all going well
Except for when I load a 3D file from Vcarve Pro
It loads the file fine no problems
But when the Router starts cutting the file eg If material surface is 0 After about 5 min of cutting the Z axis 0 Point is not at surface level any more it is gradually moving down and so is the cut
Does any body know why?
I have tried slowing it down but no difference just slower
Regards
Jcoro

[ger21]

Try reducing the Z axis acceleration by 50%.
Sounds like your losing steps on the Z axis, usually from trying to move it faster than the motors are capable of.

[Jcoro]

Hi there thanks for the reply I'll give it a go see what happens
regards
jcoro

[Vance]

I mentioned in another post that my Z axis moved unexpectedly before I changed the vfd-spindle wiring to shielded and grounded. I was building the machine and used unshielded wire. The Z axis worked fine but apparently had some RFI influence over the Z stepper causing it to drop. Once I shielded it, the issue disappeared.

Vance