I had to PM the file to you as Firefox kept crashing when I tried on this thread!? My message for anyone reading this thread: @unknownuser said: Subject: Can pistons be prevented from stretching? @cphillips said: The strength of a joint is directly related to how big (massive) the objects connected to it are. If you can post the model I can make some specific recommendations. My browser kept crashing when I tried to attach this to the forum post so I tried here, assuming this posts it works! Odd... My model basically needs to defy the standard physics of this I think. I can think of a few redesigns to change how the tilting mechanism works on this one although that tends to destabilise the central pillar. I know these things are possible in real life, I've seen engineering and funfair rides which do what I'm trying to do (in part at least) - I just don't know how to go about them in this. I guess in this scenario the tilter needs counterbalance, but as there is no weight control I don't see how to do this too easily. Thanks in advance for any help, it is much appreciated!

When I try to do what you suggested above it doesn't change the name or default value, it just locks me out of the UI control pannel. Specifically, I change This : slider('piston299781') to this : slider('Left',0) And no changes occur to the physics but if I click off the UI box then the UI will not re-open any more. Any suggestions?