Re: [Frameworks] Pedal Powered Phenakistoscope

From: David Tetzlaff <>
Date: Fri, 7 Oct 2011 15:05:01 -0400

I can't really tell how the device works exactly from the stills or video. It appears that the large pedal driven disc is merely a shutter, and the video camera looks through the shutter to something on the other side, and then the video projector displays that image on the screen in front of the user. Is that it? What is that something on the other side of the disc?

How does this work without the projector? What spatial relationships are required between the viewer, the disc and the thing behind the disk -- how close do they have to be to each other? How does the size of the disk play into this? If the disc has to be the size it is in the existing device, and the viewer has to be as close to the disc as the video camera is now, you won't be able to use the recumbant pedaling position unless the viewer is looking through the bottom of the disc, which would make the whole thing pretty tall and probably defeat the purpose of portabiity...

One thing you might try to use as a 90 degree transmission is a close-quarter drill attachment, such as this:
I don't know if the gears in this one are strong enough to take the inertial force of your disc. I assume you can get similar devices from other sources that would be sturdier than what Harbor Freight sells, though more expensive.
You'd mount the attachment at the hub height of the disc, with the disc linked to the part of the attachment that goes into the drill. The attachment would not hold the weight of the disc axle, so the axle would have to be supported independently, with one end connected to the drill attachment to drive it. The bicycle gear, then, would be on a similar axle, independently supported again, probably on both sides, as inside a bike fork, that would extend on one side and clamp into the drill chuck. This gear would be driven by the pedals in the sort of 90 degree horizontal to vertical chain path you have now.
Making these axles and attachments sounds like a lot of hacking work, though...
It's possible a beat-up old bike chain might have enough play in it that it could could make a 90 degree twist over a long enough run. That would be simple, but probably wear out or break easily.
Another possibility would be to use automotive type pulleys and rubber belts. A belt of the length required should handle a 90 degree twist. I think they even make such belts and pulleys with teeth, for a more positive grip and drive. (Without teeth, you'd just need to build in a tensioner to keep the belt taut...) You might talk to an auto mechanic or an industrial supply company... This method, I think, would be more reliable than the drill attachment thingy, and perhaps easier to construct...
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Received on Fri Oct 07 2011 - 12:05:10 CDT