Motorized Axworthy/Flying Ghost Pulley System for Halloween

thingiverse

This is a motorized pulley system to make your own Axworthy Ghost for Halloween. An Axworthy ghost is a spooky ghost that is made to look like a flying apparition through the use of fishing line, swivels, pulleys and some kind of motor. There are many examples online of people making them from bicycle wheels, electric drills, and other items found around the home. But, I did not find any 3D printable versions so I thought I's make my own. I will be the first to admit that this version may be a bit over-engineered, but with 3D printing why not? Fishing line is strung between the pulleys and the ghost/s are attached using fishing swivels. As the pulleys rotate, driven by a motor, the fishing line is pulled around following a path between them carrying the ghost/s with it. This is just the pulley system, no ghost provided. I purchased a cheap light version from amazon but you could definitely 3d print something. Just keep it light weight. There are three assemblies provided: Drive Pulley, Tension Idler, & Idler. They are designed to mount to tree trunks/branches using ratchet straps or screws (I recommend straps). A single hex bolt allows you to adjust the pitch and roll of each pulley to account for branch angle. You will need to print at least a Drive & Tension assembly for a simple back and forth path. **Drive Pulley Assembly:** - Houses a 50 RPM shaded pole AC induction motor to power the system. - With an effective pulley radius of 3.5in (88mm) this creates a ghost speed of ~1.5ft/sec (0.5m/sec). I was going for a dementor like eerie floating feel. - Motor is connected to drive bolt via flexible coupling customized from [marcoalici](https://www.thingiverse.com/marcoalici) **Tensioner Idler Assembly:** - Helps add tension to the fishing line that runs between the pulleys to carry the ghost. - Can leave ratchet straps loose until fishing line loop is attached and then tighten straps to compress spring until desired tension is reached. You can also leave straps tight and use the fishing line notch on the top of the pulley to hook the fishing line and pull it around the pulley to tension the line(this requires optimizing/iterating the length of the fishing line loop). **Idler Assembly:** - Provides additional pivot points on the path. Great if you want to make a more complex path, i.e. triangle or square. **Future Plans:** I would like to add a speed controlled DC motor as an option so the travel speed can be tuned.