Rostock Plywood Eliminator

Designed to be a replacement for the plywood on the rostock.
Hopefully will make a triangle-like frame out of 5/16" threaded rod to connect the top and bottom of a Rostock Delta Printer
I designed this mostly as a hardware sourcing ability, but it could also be used to add a more expandable approach to making a rostock?

UPDATE 10/13/14:
I found an obvious mistake once these were printed and I was assembling the part. Captured nuts DO NOT work in the way I was trying to make them work.