I'm working on some SC units as well.
But I kind of use a different method as I dont want to have my designs static. (I want movable guns and such)
Supcom -> blender -> designspark mechanical
In the last program I import the mesh and completely redraw them to make a solid part that can be properly sliced.
This way i can also choose to leave the weapons out to print them seperately. additionally, it allows me to prevent support material being nessecary in places I cannot reach.
Currently im working on the Cybran T3 battleship which is getting close to completetion but i got a Rhino ready:
Rhino assembledRhino partsI want to make many more units as I simply love how they look.