Since i updated kethane to 0.7.6 i'm having the same problem as Tark, i guess something changed, if you look at the part at the VAB you'll notice that there are some fields missing for the 3d printer. Kethane 0.7.7 is out, will test it and see if it get fixed. Edit : So no luck, 0.7.7 does not fix it, i guess this mod needs an update to work with the latest kethane mod.