I am trying to animate a train that I got pre-rigged from Blendswap. I got the wheels to turn properly but am having trouble with some parts following the mesh (see video below). I found that when I parent the lattice object to an empty that controls the train's movement nothing happens. The lattice has copy position and copy rotation constraints applied in order to move the connecting rods, so I can't turn them off. I've tried parenting the bone to the empty, but then the movement doesn't work. I've also tried parenting to a bone and using a child of constraint above the other constraints to no avail. I'm using Blender 1.79b.