Neptune Theatre needed a bed that would extend and retract into the set for a new play, The Last Wife. The challenge was all around tolerances. When I started building the bed, the set hadn't been constructed yet. So can you guess what happened? Of course, the final tolerances were just too tight for the design.
One quick rethink later and the problem was solved. I recycled a chair lift destined for the landfill. I stripped down the mechanism and instead of having the motor go up and down the chair rail, I bolted the motor to the floor. Then the rail would go in and out extremely accurately. Worked flawlessly for the full run of the show.