This was a bit of a challenge put to me by a colleague who was trying to extend a simple animation.
The chrome pistons push against the glass plate. As the mounting holding the six cylinders rotates and the plate tilts, the pistons pump in (at the top of the rotation) and out (at the bottom of the rotation). Making the animation work with the plate rotation added was the difficult bit.
My solution involved my first use of Parameter Wiring. Took a little messing about, although if I'd put the centre
of rotation of the plate in the right place I might have solved it sooner :o)
Having got the hang of the basic use of Parameter wiring, I've used it in a number of other projects, notably the
JCB Mech, where I used it in rotating the elbow and knee joints.