Summary

Clips around the vertical X smooth rods on the prusa I3 and allows you to use your digital calipers to level the print bed.

Instructions

This is my first openscad project, It's parametric and I've set the parameters to what works best for me. I printed this with PLA, and it works pretty well to get the print bed level with respect to the X smooth rods if you don't have a dial gauge. After that, you need to adjust the (preferably variable) Z endstop to get the proper bed height for printing.

Edit: I just created version 2 which has an option to rotate the tool body so the open slot is on the bottom. This makes it so you can remove the tool without removing the calipers first. Also, I added a picture that demonstrates its use.

Prusa I3 Bed leveling caliper jig