Upgraded my Taz 3.1 to 4.0 specs with a new Z axis Lead Screw. The Taz 4,0 has an aluminum plater the X ends, z Nut and Z bearings attach to.
Being in the middle of nowhere and no machine shop, I printed the X End Plates. These worked but had a lot of flex in them. SO I redesigned the X ends so the ends are integrated with plate and stiffened them up.
Included is the freecad file and ini file for PLA I used.