This is a pattern for casting out T nut blanks for a 7 inch rhodes shaper. I printed this with 5 layers thick walls, then sanded it slightly to give it a very small amount of draft/taper and use it as a pattern to cast the blank for the T nuts out of aluminum. The aluminum T nuts have held up very well so far and are still in use on a daily basis.

Customized version of http://www.thingiverse.com/thing:218666

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=218666

Using the following options:

tolerance = 0.008
thread_p = 0
thread_d = 0
hm = 0.36
w = 0.8
h = .61
l = 4
wm = 0.43