I think it's time for an upgrade, however. I need to do some research. I think I'll stay with the same filament style technology, but with just a more refined printer.
Translating aluminum to plastic seems to be more an art than a science. Almost no "rule of thumb" ratio seems to apply. The plastic is just too flexible and responds so differently when stressed. That said, I roughly doubled the tub thickness all around and then added gussets and bosses where I had the space. I didn't run any stress analyses to see what that means because 1) I don't know what any real world loading conditions are and 2) plastic is tough to stress model, especially printed parts which respond so differently than a machined or molded equivalent. So, real world testing will be required
.CAD models: Thanks. I've got a few done for the RC10, but I'm not planning on replicating the whole car. What parts have you modeled?
Along those lines, you can download complete models of the B4.1 and other RC cars at http://grabcad.com/. Example: http://grabcad.com/library/team-associated-b4-1-factory-team
I don't know how accurate they are, but they look very impressive.
I think a 1/18 RC10 would be a cool project. Maybe steal a transmission from an existing model or go direct drive. 
