20 mm Ball-to-Ball Extension Arm

This is a set of 20 mm ball-to-ball extension arms designed to work with 20 mm ball-and-socket mounting systems. These mounts are commonly used for securely positioning phones, GPS units, dash cameras, action cameras, and other vehicle or motorcycle accessories where a slightly larger ball provides increased stiffness and load capacity compared to 17 mm systems.  According to Chat-GPG, brands that use 20mm balls include Bulletpoint, 67 Designs, Expedition Essentials, Tackform,  and Mob Armor.  This 20mm ball is not the same as a 1-inch ball used in some brands.

Two lengths are included on the single plate--delete the one you don't want.  They are 3 and 4 inches long, center-to-center.  The parts are intended to be printed vertically with an apron, although the apron may not be necessary especially on non-bed-slingers. The arms have a central channel that forces additional wall generation and when printed with PETG they are quite strong.  Because these are used with swivel connections that are not completely rigid, it would be hard to put enough torsional force on them to break them in normal use.

In my limited testing of PETG and PCTG filaments, Bambu Lab PETG HF has produced parts with the most uniform clamping and the smoothest swivel movement.