Last May I removed this DC motor and corresponding belt rotation systems from an old VCR. I have the photos from that day somewhere… I’ll  post when I find them.

I finally got around to putting them to use. The system is mounted on masonite and other materials found on the junk shelf. I had to figure out how to mount the rotating parts in a way that caused the least friction. There was a VCR play system (where the tape ribbon gets extracted and put through the video head system) on the junk shelf that had various sized capstans and shafts– one of which fit the small black wheel perfectly.  Turns out the VCR play system was the EXACT one I left on the junk shelf 4 months ago! I took off the relevant parts, adapted them to the masonite system and prest-oh change-oh the system was complete. Then I watched it revolve around and around while imagining what sort of naughty or nice things I could use it for. The first idea that stuck was a zoetrope (which is apparently “a very first year thing to do”).  Well, who cares?  Not me.  I like doing projects where I make things I don’t know how to make.

What ended up happening is this: the moving image is about 1 second at 22 frames/second.  I wanted the ball to be red, but the sharpie bled through– which actually has an interesting effect for the foreground of the moving image. A kind of fluctuating sin curve. I can imagine the foreground being some kind of context for the moving image beyond.  I can also imagine making the image more interesting by shrinking the frame, situating them side-by-side in a descending spiral (like a spiral staircase) to the bottom. The central image would be isolated from the images on either side by a floating frame, suspended into the zoetrope. Greg Borenstein and I were talking about interposing a transparency between a bright light and the zoetrope image, which would project the transparency onto the moving image, providing fixed context.

This is a video I made for CommLab that shows the mechanism working.  The music is The Magnetic Fields, Chicken With Its Head Cut Off.

Other ideas for this system include a series of on/off switches that are acted upon by the movement of the motor/belt system. Similar to what I made for Systems class last summer, but smaller, more manageable and more self-contained. I’m considering adding a micro camera to be able to show the image on the zoetrope on a projector or TV, though frame rates will have to be puzzled out. In terms of sculptural representation, it would probably be something less figurative and more atmospheric. I have been influenced by sculptors such as Jon Kessler and Arthur Ganson, and in emulating their aesthetics for a while I would learn a lot about mechanisms and moving parts, eventually my own voice would become clearer. At least, this is what’s worked for me in the past. Pretend until you wend (your own path). If I assume I can’t do it, it ends right there.

One thing I plan to do is mount LEDs on the smaller spinning wheel.  I’ve wanted to put electronics on spinning wheels for months now. It’s an interesting problem, since the power and ground terminals are fixed and power must be provided to a component attached to something that is constantly revolving. It’s not hard with something moving back and forth on any axis, but a revolving object reels in any wires hanging off. So to run an LED on a spinning wheel with power originating from a fixed point off the wheel, the connections must be independent while remaining in constant contact.  I know Jason Krugman dealt with this issue with his spinning florescent light, and Jon Kessler deals with it as well. Jon told me he uses the mercury connection (the Mercotac model 430, which has four conductors running 0-250 volts, two connections at 4 amps and two connections at 30 amps), which is probably what Jason used in his project. I don’t want to use mercury. So instead I’m making a plate and brush system out of a huge sheet of solderable copper plating I found in the garbage in the pcomp lab.  Wonderful. Now I have a highly conductive, flexible material to play with. The brushes might be made out of fine copper mesh I found on the junk shelf– increased surface area and forgiving pliability.

I imagine the user will have to figure out a puzzle of some kind (possibly the cigar box combo lock, which I’m still working on), which will tell the Arduino to turn on the motor. The motor also has the ability to receive pulses through a third terminal between the power and ground. I could send a PWM signal to the motor to speed it up or slow it down without having to deal with analog.  Though analog is really fun.  If I make the system into a zoetrope, I could use photoresistors and pots to control how bright the LEDs are, or other aspects external to the zoetrope itself.

Here’s some pics of the system as I was building it.

The back of the big wheel mechanism

Back of small wheel. The metal part it's mounted on came out of the VCR quite nicely.

Things nicely spaced

Close up of the frames on the zoetrope. The green strip at the bottom is foam from the junk shelf used to make the paper more rigid and weigh it down.

This will be the copper plate beneath the small wheel. Power from the LED mounted on the small spinning wheel will be transferred to ground by brushes in constant contact with this plate. The power will reach the LED via another brush system on of the wheel.

Tags: arduino, Arthur Ganson, cigar box, hacking, Jon Kessler, motors, PhysComp

This entry was posted on Saturday, September 26th, 2009 at 11:10 pm and is filed under CommLab, ITP, PhysComp. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.