Set two 96-inch boards on edge, parallel and 93 inches apart. Set four 96-inch boards perpendicularly between them so that they're spaced 30 inches apart. Screw two screws through the 96-inch boards into each end of the 93-inch boards. You now have an 8-foot square frame.
Lay two sheets of plywood on the frame so that their 96-inch edges are parallel with the 96-inch boards. Position the sheets so that they're flush with the outside edges of the frame. Screw the sheets to the frame using 16 screws for each sheet, so eight screws enter each 93-inch board.
Turn the frame over and screw four wheels next to each corner, inside the frame. Make sure that the wheels can swivel freely. Screw the last two wheels in the middle of the frame so that they're spaced 48 inches apart and 23 inches away from each 96-inch board.
Drill a 3/8-inch hole through the 46 1/2-inch center of one of the 93-inch boards. Insert your eye-bolt through the hole and secure the nut on the inside of the frame. Tie your rope to the bolt to pull the slip stage on stage during a performance.