Here is the calibration part I printed on my Printrbot Simple Metal. Another Calibration Square
I scaled it up 2.5x and after printing I measured and it was within 0.15m off all expected measurements.
I am working on the stepper stutter issue currently. No belts connected. I will print out a new C-XY part once I get that figured out. I think right now the stutter issue is the one actually causing me problems.