I'm sure this is really simple, but i've been having a pretty hard time wrapping my head around how to create rig up two rigid bodies like a hinge. I'm trying to create an object that has "legs" that attach to the underside of the object and rotate in one plane about their connection joint. I was hoping that I could just make all of the pieces (including the pin that hold the two pieces together) rigid bodies and then just let the simulation figure how they will move (the thing is being dropped into a bed of rbd grains) without needing to constrain or rig anything, but the result I get is that once forces are applied to the "legs" the pins move out of place and the simulation breaks. Any help would be great. I have been trying to find tutorials for this but nothing seems to quite address the problem I have been running into, plus I don't exactly know what it is i'm looking for. Thank you!