Coupling Saver for Lowrider2 CNC

Lowrider has a heavy gantry and thus has no need to support spring couplers from the bottom under normal operations. However it's easy to accidentally over-stretch the couplers when jogging the machine around.

These 3D printed sleeves will protect the couplers and will also allow one to use sensorless homing in Z_MIN direction.

Print with 0.2mm layer height. Then snap around the coupler to install. You may want to loosen set screws on the lower side to compress the coupler slightly for easier installation.

Visit [this forum thread](https://forum.v1engineering.com/t/lowrider-skr-1-3-dual-y-and-z-tmc2209-uart-sensorless-homing/14596/14) for more information.