Current project: Piccadilly & 73TS

@tbtc, I have done the same for 73TS with Sketchup in OO scale. For fitting the body and chassis together in Sketchup is easy to do. Just copy them both into the same window as their own entities and move the two parts together at specific points. This will tell you if parts fit. I would leave a 0.1 mm gap between mating edges to allow for expansion. And if too tight, you'll have difficulty in getting the components apart. Ultimately you will have to do a test print 3D model, as you will find some wall thicknesses and other real world mechanical issues have to be corrected before the production model is arrived at.

Unfortunately Yes ;D

Actually, they don't ever bother wether you're printing a test product or not : They print it, period. Then, if it breaks apart when you seize it, well... You call it a test model and modify you 3D model ;D

Its nice to see you trying. At the moment, I have no money in my modelling fund due to building a new layout so my finished product may take some time to complete.

The guidlines I describe are on the Shapways website and describe the various rules for different materials, such as wall thickness, detail level, etc.