Thread calibration printer extruder test

Nov 17 2019 new design
https://www.thingiverse.com/thing:3983705

This is a simple overhang calibrator for printing more accurate threads. With it you can measure the thread clearance and sag of the overhanging threads and tune your printer parameters and print better threads.

These threads are M10x1. In Fusion 360 the thread tolerance is class 6g for the bolt and 6H for the nut. I measured in the CAD model the nut to bolt axial thread clearance at 0.13mm.

The nut has 20 notches and one notch has a pointer. The bolt also has a pointer and the angular position difference allows measuring of the thread clearance.

Print the nut and flip over the bolt before printing. Print with no supports on a raft then screw them together (the raft removes bed leveling accuracy from the measurements).

If you have printed perfect threads then when they are fully screwed together the pointers should go past each other by the thread tolerance clearance or about 2.5 notches (0.125mm). In thi