i've been trying to build a model that has some long beams with hinge
joints at the ends of some and masses at the ends of others (imagine a
mobile) and have noticed that if the distance between a joint and the
elements connected to it is large (or the object connected to it is
massive), that a wobble and/or sag may develop. is it just me or are
the hinge joints "stretchy?" are there some guidelines/tricks to
follow to keep this from happening?
also, how solid is the floor? i connected several long beams end-to-end with hinge joints and
found that one end of it would sink into the floor when fully extended, but if i coiled it around
a bit, it would skate along the surface.