Printer calibration pyramids

I needed a simple method to check the calibration of my 3d printer as circular prints were coming out slightly oval

I designed these 2 simple towers so I could check the sizes with my vernier calibers to ensure dimensional accuracy

I have included the opens cad files so others can adapt or customise the project more easily

the pyramids have raised text on the X Axis "" as I discovered early on it was easy to take them off the bed then forget which was the X and Y axis and have to reprint them then mark with a sharpie