I bought EdgeCAM and a Sherline 4axis CNC Mill, am running Mach3 and have been having some problems with losing the home and origin positions during machining. I am cutting an organic shape that has been laser scanned. The Laser scan and resulting CAD model are fine. It's the EdgeCAM to Mach3 to Sherline process that is causing some problems. I am losing my home position by 0.015" in the x axis, 0.020" in the y axis and 0.010" in the z axis. I set the home before machining using an edge finder, run the program, and when I check the home following machining I am out the values listed previously. The problem occurs irregardless of speed, so I'm not going to too fast (22in/min as recommended by Sherline). If I run the program a second time, then the error is cumulative and thus worsens.
I've checked backlash and repeatability on each axis and I am within tolerance (0.001"). The issue arises when I run complex 3D profiles as most of these organic shapes are.
I am cutting in 3 axis mode and have manual code written for a 180 degree indexing operation to machine the bottom side. I am using a Mach3 post for EdgeCAM that I found on this forum. I am running Mach3 confgured for Sherline as downloaded from the Sherline website. I am cutting modeling board which is light weight and using brand new cutters.
The whole reason I bought the Sherline was for precision. My TechLine CNC router is more precise right now. The TechLine runs a different Mach xml, but G-code is generated by the same Mach3 post for EdgeCAM.
Can anyone please help or offer suggestions? I am just about ready to return the Sherline and have many thousands invested.