hi guys
cannt figure out how to constrain the parts in order to see the motion. Green wheel (cam) rotates and make the purple roller rotate as well within the slider moving up and down.
would be very appreciated if someone set the rigid body motion in blend file. it will be much easier for me to find out how its done 
After some attempts to get it done right i came up with this. [video]http://edm-norway.com/video/cam.webm[/video]
Why the blue roller doesnt want to lift back. It penetrates the wheel. I set the green wheel as passive and the blue roller as active with some location and rotation limitations.
I tried it with no luck. I would be interested in a solution.
You can have a look at this and see if it is any use to you; it seems to do what you want.
1r2.blend (733 KB)
thanks a lot
this is exactly what i need 
hi there blender guru
meshes penetrate each other and bounce (bounciness set to 0). How to prevent penetration at all, make the objects feel like they 're made from steel. 6.blend (596 KB)
Sorry it has taken a while, haven’t had much time. I changed a few things: the height of the piece that sits in the groove since it was a bit of a tight fit in the inner groove; I also changed it’s rigid body collision to convex hull and lowered the friction; I set the origin of all the pieces to centre of mass; I slowed the animation down. For the wheel I applied the sub surf modifier at level 2, which smoothed out the animation. It seems to work.
6rev.blend (1.52 MB)
Again very appreciated for the work and time you sent on it. I’m building the libriary of simple mechanisms to help kids and students understand how simple things are woking, the project is totally noncommercial so your support is very helpful for me, thanks
