Amazing Z-Wobble Fix & Torque Increase

The files here are for the Prusa i3

This modification worked extremely well on my Mendel90 - the Prusa and Mendel90 share a lot of common design aspects so there is no reason this would not work for Prusa machines as well. I can clearly see from prints that Prusa does not suffer very badly from z-wobble except for when speed is required - like all printers! This mod will allow you to increase print speeds as it creates tension on the z-axis which keeps it very stable - it's like a bow under constant pressure. I assume the smooth rod is hardened steel, in which case it should work forever.  The added bearing pushes on the x-axis by about 0.4mm and you should feel a big change in stability rightaway. The Prusa mods are slightly more involved as I could not find goo6d clearance for the 29mm shim I would had to add to a skate bearing. So next best thing was to place a smaller bearing in line with the z-axis - it should do the same trick.

The photo is 0.2 layer height on a 0.6 nozzle, printed at 90mm sec

You'll need :

2x OD13mm ID4mm Height 5mm bearings 

2x 4mm x 20mm(length) hex (cap) head screws

Another great modification I have made is switching to 12 tooth pulleys - this increases torque by about 24% and resolution, but you'll need to change firmware settings. 

These two mods have put my old Mendel90 in a different class. 

Some of the photos are macros. https://youtube.com/shorts/1vMGGw9SHaw?feature=share