I've downloaded some basic blowgun dart cone designs that I desperately need to be able to manipulate and change. I have no experience with CAD systems but I have a  3D printer and need to make prototypes so I can test them before I spend the money to have production dies made (plastic injection). Can any one help me? Who ever does gets their choice of the products I intend to manufacture here in the near future which consist of pneumatically powered blowguns for hunting. these blowguns are a viable hunting weapon at over 50 yard and I'm looking to increase the distance to 100 yards. I have included some of the CAD designs I have downloaded. Thank You.