Hhhmmm looks like a very good idea. Selling..... If you make it from 'the ground up', then you could sell it. Most free sites that i visited saying that it is for personal usage only. Not for selling, unless if u are willing to give some 'royalty' to the design owner. Needs consensus from relevant parties if u did not design it yourself...

I finished making a 2 foot long "Chinook" double rotor helicopter. Now in a 70% completion making a 4 foot long USS Saratoga Aircraft Carrier. Dunno how to post pictures yet but will do so when i know how...