So my problem is this: I want to build some "contraption" that will require wood, motors and other parts. Problem is: I do have a rough idea of how what I want to do will look like, but I DON'T want to waste material to see if it works or not. I know, inventions usually require a lot trial and error, but as I have my PC and am a fan of the "Tim" and "Crazy Machine" Games I thought: - Why isn't there some pc software where I can try my idea out, BEFORE I built it ? I have so far stumbled across: Autodesk Inventor 2014 (Trial) and Algodoo. Those programs are fine for what they are, yet they are far too complicated. I need something simple, with a physics engine and a 3D Environment where I can whip up some ideas and "test" them. For example set properties for different parts (rigid, moving, wood, metal, pasteboard etc.) and then click a "run" button to see how it would behave. Thanks in advance.