While working on this design, I published a y-axis back brace for the three i3v versions. There is a test print for each version that takes about 30 minutes or so to print & weighs about a .25oz. If someone with an 8" i3v could print the Y-Axis_i3v_8inch_TestBackBrace_Rev4_repaired.stl located here: http://www.thingiverse.com/thing:1302473 , that would tell me whether I have the hole patterns correct for the 8" version. I got the dimensions from Colin, so they should be correct. The attached screen shows what the brace would look like on the 12" i3v.
Y-Axis_12inchBackBrace.JPG