I've spent most of the day trying to work out whether I should be using Flash or Blender for some new mechanism animations I'm planning. At the moment I'm leaning towards Blender, it seems really powerful but I'm just in the foothills of the learning curve and it looks like a long way up!
I've also made a start on my next project for the mechanisms section. In this model the cam is fitted on a short axle which thread inside the tube with the handle, that way you'll be able to pull out the cam and replace it with a different one. Early stages but I think it'll be a fun model to demonstrate cams in action.