Alibre design is a decent parametric 3D modeling system that has a (legal) free (as in beer) version. It looks like right now the standard version is 90% off.

Alibre design is a decent parametric 3D modeling system that has a (legal) free (as in beer) version. It looks like right now the standard version is 90% off. http://www.alibre.com/ http://www.alibre.com/ I understand that SolidWorks is better, but it's decidedly not free if you go the legal route.