The propeller

youmagine

This is a modular propeller that can be attached to anything with a pencil-thick hole drilled into it. It's probably not stable enough to propel your bed, though - so don't attach too strong of a motor. The scad file is designed to be modular, allowing you to adjust various parameters such as the pencil diameter and more. There are two modules that can be used for debugging wing attachment. I had to make the holes for the wings slightly larger than the wings themselves in order for them to slide in perfectly. The parts are secured to the pencil using two short M3 screws, which are around 10mm or 12mm long (the length is parametric). You can screw these directly into the PLA material if you choose to do so - and it's worth noting that doing so by hand will allow the screws to cut their own thread.