AutoDesk Fusion 360 is not open source but is free to makers and education. To get the free copy: download trial, when trial is up and it asks for license number there is a checkbox to say you will not make money on the products you make. (citation: personal experience)
AutoDesk Inventor may be available as an educational trial, for members of PS1. (cite?)
AutoDesk Inventor may be available as an educational trial, for members of PS1. (cite?)