Hello, didnt know if this is the right place to post this, if not please tell me where can i post it.

I have made my own cnc machine, basically for cutting wood, its a design similar to the JGRO, but in alluminum, its driven by steppers and 13 TPI 1/2" diameter leadsrews, with a gecko g540 and mach 3

The thing is that sometimes, while im machinig, the hole design is moved in the y axis, and the hole piece is ruined.

For example, lets say I reference the machine to a point 0,0,0 and i start machining, then in the middle of the program the y axis is moved, and if a move the machine back to the reference point that is supposed to be be 0,0,0, it is now, lets say, 0,150,0, being x,y,z in milimeters.

I dont know whats is going on, and was wondering if anyone have a clue and can help me out.

Thanks.