Prusa 3 Vanilla with 28cm Lead Screw Stepper ( Pololu part 2268 )First off, design of the original parts is from Josef Prusa. https://github.com/josefprusa/Prusa3-vanillaI am publishing just the STL files as I think this is sufficient. I will offer the scad if anyone ever asks for them.I am currently using this on my printer and it works for me. I can not say this is a great upgrade. It's a incremental improvement. It offers faster z movement and a more rigid z/x system. It looks cool.It was a large effort to install and it will get misaligned if the head hits the platen when homing. I plan on wiring a second z stop switch (one for each motor) to get both sides at end when homing. It's a primitive solution as the other motor will be stalled until they both hit end; however the design limits racking to ~1.5mm so it will not overheat in the 40 steps or less this will take. Overall I fuss with calibrating these just as much as with the original threaded rods. The linear rods for the z axis will extend above the top by some 37mm or so.I had some concerns these could jam as these shafts are part of the motor and therefore lack the flex offered by couplers. This is not a problem. The shafts are Tr8×8(P2) lead-screws and when used with the included traveling nut they allow for angular deflection with minimal effect on positioning.