Well, foo.
I did a test print the other day and determined that my X & Y axes aren’t perpendicular.
Certainly not an insurmountable problem, but annoying none the less.
The plastic will shrink in an undetermined nature, which may cause your calibration objects there to be less accurate.
Redesign them with cylindrical cutouts inside the lengths to account for this.
You could print two cross shapes and reverse them to check for skew on a symmetric object that should shrink in a symmetric fashion.
On what kind of printer is this printed?
I printed this on a SeeMeCNC H1.1 printer. It’s a variant of the Huxley RepRap.
@John_Bump I like your idea. I may try that to rule out non symmetric shrinkage