The calibration on a new printer is finally at the point of testing real objects. This design was made by just measuring out some nuts, screws, and a bearing that were laying around. This will be used to estimate a fudge-factor for sizes in the future.

Screw holes for M3, M4, and M5.
Hex nut holes for M3 and M5.
A square nut hole for M5.
Screw head holes for M3, M4, and M5.
An outer diameter hole for a 608Z bearing.
An inner diameter column for a 608Z bearing.