Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4460189.

Superior bearing block, eliminated concentricity errors. As long as your screw is straight you should have no wobble. Requires some bearings and stuff that i will be updating this summary with a BOM soon.

You must invert the nut, which is the right thing to do regardless, so that the weight of the bed is NOT compressing the spring, or you will lose Z capacity.

2x F688 Bearings Spider or spring type coupler max length overall 30mm Thrust bearing Shaft Collar Spacer, recommended 0.5mm thick, change Z to suit your setup.