Nick,
I disagree with your opinion and I would ask you to take page one to the electrical shop put two servo motors face mounted in a plate ( beam ) then add two reaction weights accelerate them to the maximun rpm acheavable in
.5 of a revolution then at that point decelerate them to a stop 180 deg later ie there start point.
Holding onto a chair with both hands is only practice for holding the pan after a curry or AMS into a G if the teabag gets it wrong.........
Jiff