Introduction: This Is the Prime Mover (a Bicycle Wheel Powered by Computer Case Fans)
Welcome to the Prime Mover!
Although this is my first Instructable, hopefully it won’t show too blatantly. The Prime Mover is a bicycle wheel driven by Computer Case fans mounted tangentially on the wheel. In this case I used fans that have multiple colored LED’s in them to add a cool effect to the wheel in motion. I realize that one could argue the prime mover(s) is really the set of 9 spinning fans; I’ll leave you to draw your own conclusions.
This contraption was built as a piece of kinetic art (once again you can draw your own “art critic” conclusions), however it could easily be re-purposed to drive a load of whatever your imagination conceives. In the middle of the wheel are a set of Hokey Spokes (www.hokeyspokes.com) to add some POV lighting patterns. Note: This is version one…for version two I plan to use my own string of HL1606 LED strings driven by an Arduino and I’ll probably employ more powerful, Ball-Bearing fans.
Here is a Video of it in action: http://youtu.be/0eQlW-90Csk
How it Works: The fans (12v DC 48 cfm / 80mm) propel the wheel at about 60 RPM.
Electricity is conveyed to the fans by a brush / disk assembly (illustrated below --not to scale) for the positive with the metal frame being negative. Once you see the photos, the construction is pretty self-explanatory.
This assembly is made from a platter out of a (failed) hard drive, and a DVD (or CD) and bolted together. The front of the assembly makes contact to a Carbon Brush commonly found in electric motors, and is mounted to an insulating layer (DVD) and the complete assembly is fastened to the hub of the bicycle wheel (I used silicon glue). One of the bolts on this spinning assembly has a wire attached to it and conveys electricity to the fans mounted along the perimeter of the wheel.
Once the 12vDC has been conveyed to the wheel, the possibilities are limitless as to what other lighting or gizmo’s can be added to the wheel. The Hokeyspokes ordinarily run on 3 AA batteries (4.5vDC). I modified them (totally voiding the warranty) to take power from the wheel. I used a voltage regulator to bring the voltage down to 5 vDC, which works fine. These Hokeyspokes have been running flawlessly for years using this scheme. One last suggestion is to ensure you use adequate power, especially if using more powerful fans –the ones I’m considering for my next wheel pull almost 2A per fan…therefore I’ll likely use a PC power supply. I hope this inspires the collective brilliance out there to come up with more cool stuff.
Here are some illustrations of the Wheel-
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