Howdy from Grapevine, Texas.

I have a calibration problem I'm not sure how to handle.

I set-up my cnc router, "Arnold", according to Planet CNC instructions.

Needles to say when I do micro-step calibration it is right no the money. I used a machinist ruler that measures 1/64 of an inch and a 10 degree V bit to do my calibration. Like I said it is right on the money. I've done 2" calibration all the way to the width of the table, 27 1/4".

The problem is, the larger the file the more "off" the travel is in all axis.

When I run a 123kb file and return home, the X coordinate is off -.03828 from true home. Y is a bit less and Z is the same thing.

But when I run a larger file which is 1,305kb can be off by as much as 1/4 inch or more off.

A friend suggested the voltage my be off but I measured 24Vdc right on the screws to the controller and 40.35VDC to the drivers.

When I use the old MultiCam electronics it's right on. That tells me there is no slop in the screws.

Any help would be appreciated.