Prusa Z axis, so many problems yet one simple solution !

Note: This has worked perfectly for more than a year and is still valid. BUT, I wanted to go further and get rid of all the crappy linear bearings and poor leadscrew nuts. Done, I even managed to get rid of the vertical smooth rods, the lead screws can do the job (although TR10 would be more rigid, TR8 are acceptable) see here: https://www.thingiverse.com/thing:2594693

WARNING:
Don't be misled by the negative comments found here. This WORKS ! Unfortunately some people either misunderstand or