My friend who helped me out with the prop rings brought a
3D printed quad frame he had made with his high resolution 3D printer. It seems pretty nice, and the arms are definitely sturdy enough.
There's 4 arms, a top plate, a base plate, and 4 feet. After printing everything out you can glue them together with CA. We had lightly glued everything together at the conference so people could see the results. Two of the feet came loose and got lost on the way back home. I may have access to another 3D printer soon; if not, I'll just cut out a duplicate from 1/8'' ply.
You can see a bit of the striations left over as an artifact of the printing process. I'm not sure if that could be eliminated by proper tuning or if it's a limitation of some part of the printing process.
I'm not sure of the materials cost of this piece. It may be high enough, or the printed frame may be heavy enough that there's not a distinct advantage over buying a frame kit (for this size about 12-15 dollars) or using a material such as 3/4'' basswood. I certainly intend to explore this further in any case!
More info on the quad design by Adam Polak here:
http://www.thingiverse.com/thing:29632http://polakiumengineering.org/?page_id=1793http://polakiumengineering.org/?page_id=1989
