M8 Bolt Screw Tester

This is a test print to check the fit of M8 bolt screw threads in a threaded tube. The tube is designed with a left-handed thread on one side, and a right-handed thread on the other. Left- and right-handed bolts are also included for testing. The design offset is 0.4 mm between the bolt thread and the tube thread as this seems to work just fine for PETG prints with almost no post-processing apart from removing some whiskers if PETG is not dry. Test prints were in 0.12 mm PETG with 5 mm brim to ensure the prints stay on the print-bed throughout the printing.