Hi there, I have been designing sets for a while now...but have recently been tasked with creating construction drawings as well- normally my carp team takes care of it. I am wondering how best to make two moving platforms. One is 3ft high while the other is 20" high. The 20" one is more like a riser so I am less worried about it. The 3ft high platform needs to be 5'x6' and one of the 5' ends is a set of stairs coming down to 20". Both of these platforms need to be on casters so that they can move and spin between scenes. Ideally the casters are hidden from sight. I am most unfamiliar with what sort of structure I would need in the units to suport both the unit and the casters on them. Any help peeps can offer would be amazing. I have cads drawn up - will post them when I can.