Help! Z Axis drift during machining

[Cncnewbie]

Hi,

I have purchased a new Chinese 1325 cnc machine from china, but when running a file on this after a few minutes the Y Axis seems to start drifting and losing its position. At the end of the file if I go to zero point it is completely off on the Y axis. Can anyone give me any suggestions as to why this could be happening?

CNC router has servo motors, and is running on NcStudio software.

I am based in West Yorkshire, I would be willing to pay someone to fix this for me as this is quite urgent.
Thank you

[the great waldo]

Could be the acceleration is set too high or the machine is sticking mechanically. Have you set up all the axis` properly. Is it the Z axis drifting as in the post header ? or the Y axis as you write in the comentary? what software ? controller ? etc. You'll have to give more information for anyone to give you some help.
Cheers
Andrew

[Neale]

If you run the same gcode file twice, is the error in position exactly the same, or similar-but-different? Is it Y or Z (as mentioned above)? Does it make a difference if you are actually cutting or "air-cutting" - i.e. above the work? How complex is the gcode file - a simple outline, for example, or a lot of small intricate moves like engraving? At the end of a cut, does the machine position display say that the tool is out of position or is the display correct but the tool not in the right place?

Need quite a lot more info to start diagnosis!

[JohnHaine]

And please could you post the code?

[hanermo2]

It sounds like electrically coupled inductive noise - this means extra phantom pulses in the wiring, causing axis drift.

Always start all debugging with the simplest state.
Leave only the fault axis motor connected, and start running programs.

Try to geta a state/program where the error show up quickly.
Now start adding more axis, spindle motor, spindle on/off, etc etc.