Fender Washer for Flying Crank Ghost

I am a home haunter -- one of those crazy people that go overboard decorating for Halloween in the same way other people do for Christmas. We go to great lengths to build elaborate DIY static props and animatronics. Now that I have a 3d printer, I'm looking for ways to use it for my haunt as I ramp up my construction.

One of the traditional animatronic props is the Flying Crank Ghost (FCG), a slowly bobbing and wafting ethereal figure that works similar to a marionette. We ultimately elect