Experiment 30: Miniature Wimshurst Machine

Inspired by a museum show on electricity I viewed while on Christmas vacation, I set about to build a small Wimshurst machine.  If you know me well, you will know that I like bigger and better and more dangerous, etc., so this small machine is only a prelude to the large machine I intend to build.  I hope to achieve 2 to 3 inch sparks.  Heh heh heh.

Anyhow, this machine works by using two counter-rotating discs to gather and transfer static electricity into a capacitor called a Leyden jar.  Once the charge in the Leyden jar is high enough, the electricity bridges the spark gap with a loud SNAP and some really cool sparks.  The sparks produced from this machine are very short but are about as bright as lightning.  The machine is quite fun to use.

Watch the video to see it in action!  Be warned, though, that the video does not truthfully depict the sparks.  They look much better in real life.

Laser Cutter Build Night: PiKnife Completed!

Tonight, I officially finished PiKnife, the Raspberry Pi-based laser cutter that cost $3.39.  While some minor issues still exist, for the most part, they do not affect engravings and cuttings.  Thus, for the present, PiKnife has been successfully completed - finished, but not shelved.  I may modify it in the future for better results and such, but right now, FIRST robotics is starting up, so I am eager to devote all my waking hours to building robots.

I am quite happy with how PiKnife has turned out.  It can successfully engrave and cut from gcode files generated by common image drawing programs and is accurate and precise.  It does not need constant tweaking in order to work correctly, which is something I strive for in my projects.  Looking forward in the future, I am excited to see how PiKnife will evolve and morph.

To wrap this build log up, I thought I would share my code, a picture of the finished laser cutter, and a model PiKnife cut out of foam.  Here are the pictures:

I am positively exuberant at holding the finished Spitfire MKII miniature model.  It looks awesome!  I love the detail and the satisfaction at payoff from a job well done.  I got the CNC files from here.  If you would like to use, modify, or view my final PiKnife code, check out each file here, here, and here.  (The limit switches are unimplemented.)

I guess that's ta-ta for now, but perhaps in the future PiKnife will improve once again.  :)