He needed to fabricate two roughly 3" tall brass struts to prevent the rear bar that supports the motor mount from bending. We drew a sketch of the part, then I drew it up in TurboCAD Mac.
I 3D printed two copies as patterns for sand casting. He had them cast in red-brass. He still has to machine the top to act as a cradle for the truss rod. I was going to put that feature into the pattern, but my dad pointed out that the patterns wouldn't come out of the sand cleanly if we did. The casting is rougher than the pattern, but preserved some of the fine patterns left from the FDM extrusion, which actually looks kind of cool.
The brass casting is on the left, the ABS pastic pattern is on the right
