My ultimaker suffered from the issues outlined in the ultimaker wiki with the loose holes on the delrin plastic blocks that the springy bed mounts on. The holes were so loose that one stripped. I measured the older one, drew it up, and published. voila!
A bit of a hack job; two issues: My printer shrinks holes - not sure if its the skein (Cura RC1) or calibration on the printer...and the model is about 3% too big to EASILY pop it in the wood, so I printed it at 95 percent as opposed to resizing the model (because the model is afaik the correct per my dimensions).
Because of the shrinkyholes and the 'print at 95 percent', I needed to make the center bore larger than it should be (nearly 3.4mm) and it comes off the printer at approximately 2.8mm diameter - just small enough for the screw teeth to have something to bite into.
-- they suggest placing a piece of paper down the bore with the screw - I figured since I have a 3d printer, do it properly!
Long story short:
"Screwblock Large.stl" the one I use, 3rd on the right in the picture of 3
ABS (pla should be good)
2 partitions @ .4mm nozzle (more is fine just they won't fit, ymmv).
"Screwblock original.stl" centre in the picture of 3
Same settings, but you'll have to sand a few thou off the outside edges for it to fit in the machine, and maybe ream out the hole - depends on your printer.