my take on making the bed supported by 3 screws,
i have mounted karltinsly`s model as of now. but i see when the duet has leveled the bed and i is compensating the original brackets twists both the bracket itself and the extrusion,
by adding two more extrusions and making each bracket use 2 extrusion i think the platform will be even more stable.
i was planning to use a 1500 closed belt and the tensioners. but with the independent tensioners you can use almost any lenght. just add more tensioners ;)
brackets for the leadscrews are designed to work with the original leadscrew nut holder in all 3 places
im offshore at work for the moment so this is still untested,
you need 2 more 20x20 503 extrusions to make this mod,