Flexijack: Print-in-Place Jack with Rigid Core, TPU Hinges

WARNING:  THIS CAN CREATE A LOT OF FORCE (400+ lbs!), WHICH MEANS IT CAN STORE A LOT OF ENERGY THAT MIGHT BE RELEASED SUDDENLY.  Please be cautious using 3d-printed objects for high loads and wear appropriate safety equipment!

This is a weekend experiment that wildly exceeded expectations.    You can try it yourself with any multi-material printer that can use TPU (flexible) as one of the materials.

Settings (critical):
- Set infill to "Concentric" pattern
- Set infill density to 99-100%
- Set different extruders for infill (PETG) and perimeters (TPU).
- Set number of perimeters to match the base joint thickness (default 1.2mm joints, so 3 perims at 0.4mm line width, or 2 perims at 0.6mm line width)

The default STL file is compatible with an M6x135mm bolt, and a M6 rivet nut (which fits into the holes in the wings.

Recommendations:
- Use a locknut with the rivet nut to prevent it spinning in place when tension gets high
- Add a drop of oil/grease to the rivet threads to assist motion
- Do not max it out if you want to be able to release it easily.  Or add something between the stabilization nubs to prevent it from becoming completely vertical (see video for more detail).   Model should be easy to modify for this purpose.

See the video below for more about this weird creation: