Parameterized ball-joint, fully 3D printed

Contains 3D printable components for a ball-joint.
Hand-tightenable to secure the joint.

Original [Onshape design](https://cad.onshape.com/documents/824275ebf959ee3a55a2b673/w/afbd1ebe2e4a2405ecaba143/e/c05af6c1920250e0268944e7) is parameterized to allow customizing the ball, pegs, threads, and whether to split the ball for 3d printing

Was used as part of [this design](https://www.thingiverse.com/thing:6895143) for sailboat monitor arms