i am trying to develop a foosball game… with bars…
but i have a problem during collision between players and ball. Bars (and players attached) translates and rotates in every axes. I would like to keep only translations and rotations along z Axis.
I tried joints… but 
Please tell me how to do that.
joints should be working - search for 'foosball' on this forum, I believe mud2005 did a foosball game with physics; and I think a made a suggestion there about an approach using joints…