Customizable rewrite of the bed nut holders for the 3uP - Metal H-Bot Upgrade for QUBD Two-Up by DDeGonge888.

May work for other extrusion frame based printers, too.

STL file with settings:
Height 21mm
Frame size 20x20 (Profile 5)
5mm frame screw
4mm nose width
3mm bed screw

Use the customizer to tune for your own printer and screws!
http://www.thingiverse.com/apps/customizer/run?thing_id=740840

v2 26.03.2015:
added cone cutout to nose for easier printing laying on the side

Probably best printed on the side, layer height 0.25 or less.

Should work without support - and less to clean up in the screw nut hole :)
May need some drilling in the long screw sink hole.

Try heating the screw nut, e.g. with a lighter, before inserting.
It will melt into the socket, and be somewhat stronger afterwards.
Immediatly put a screw in to hold the correct angle while it cools down.