Thinking of doing bits, pieces, and doodads. Old Wings3D user, but been out of modeling for a while since other interests picked up. (Games -ones like Minecraft are evil in how they cause time-travel, keeping in practice with 2D software, and music software - LMMS, etc.) Figured if some of the things I'm making sell, I might get back into it a bit more. Now the real challenge will be to make models that actually piece together. It's one thing to model for looks, but I'm assuming there will be things like tolerances for fit and different material properties to watch out for. I figure if I smooth a mesh enough (within reason) that .obj should work about as good as anything, right?
Welcome, can't wait to see what you have to offer. For tolerances, I'd check out the Materials page and go through the different materials and their properties https://www.shapeways.com/materials/ For more in-site, go to the "It Arrived" section and see all the other models designed for joining. I know recently there were some transformer style robots. From there, make your design up, post it in the "Work in progress" section to get further in-site from our very helpful community.