As my z axis motor couplings tends to slip regularly, I needed a lower z axis mount, but for 6mm threaded/smooth rods, so I took the original design, and recreated it (or a close enough version) in openscad. Hope it can be usefull!

The inluded stl is just for reference, 6mm threaded and smooth rods, 25 mm between z axis threaded and smooth rods, 25 mm between z axis threaded rod and the lower "square" threaded rod.

Will add more details on parametric setting in a bit (but should be relatively clear already with the comments in the openscad file).