If the machine is cutting parallelograms where rectangles or squares were desired, the problem may be machine squareness.
This error is typically consistent and has a magnitude of 0.010" to 0.100", but depends on the size of the whole part.
One way to test for this is to:
- Cut two large squares or parallelograms
- Flip one piece upper right corner to lower left corner, top-side-now-down.
- Lay the parts over each-other in this orientation
- Compare opposite corners. If across one diagonal they are too long, and the other, they are too short, you likely have a squareness issue.
Download the following document on squaring the machine and follow the steps within.