Super Calibration Cube

This is a "super" calibration cube, it is essentially a stack of a 10mm cube on a 20 x 20mm layer, on a 30 x 30mm layer, on a 40 x 40mm layer. To use it, print it on your printer and then use your caliper to measure accuracy in the X direction for each of the four layers, this will give you four pairs of numbers (10, "10 measurement"), (20, "20 measurement"), (30, "30 measurement"), (40, "40 measurement"). Do the same for Y, and the same for Z (see the back of the stack).

Now fit a line through the points, if your printer is "balls on accurate" it will be a straight line through the origin going up at 45 degrees from 0,0 to 40,40. More typically it will be a line not quite at 45 degrees that doesn't quite intersect the origin.

Depending on how sophisticated your slicer software (or printer driver) is, you can add a correction factor to add or subtract at the beginning (this to move the line to 0,0) and a single constant to adjust the line to 45 degrees. Mathematically you are