NSTG8R
Elio Addict
Since you've got access to a 3D printer, you might be interested in checking out this software. VERY impressive "Free" CAD software, about as simple to operate as any CAD software I've seen, and TONS of tutorials....and check out their DesignSpark PCB for creating/testing PC boards....also "free".
http://www.rs-online.com/designspark/electronics/eng/page/mechanical
http://www.rs-online.com/designspark/electronics/eng/page/mechanical