Cardboard Orchestra

Tom Zimmerman at STEIM

I came to STEIM with a prototype of an invention I call “Cardboard Orchestra”. The concept is to design an inexpensive easy-to-build synthesizer to teach young people about science, engineering and music concepts. A simple circuit sequences LED’s which control the frequency of a 555 timer using a photo-resistor. The pitches of the 8 note sequencer are adjusted by placing ‘optical valves’ in between the LED light beam and photo-resistor. In my first prototype the optical valve is made with a wooden chop stick as a shaft and a rectangular piece of cardboard to block the light.

Original Working Prototype of Cardboard Orchestra

On the first day of the orientation Kristina Anderson had us build concepts of our projects quickly with cardboard and glue, which was quite a surprise to both of us since that’s exactly the material I use to build my instruments. Given only 10 minutes, the fast pace and limited materials forced me to make some inspired decisions, which I only realized over the following week of reflection. The prototypes provided tangible starting points for my imagination; fixation points to stir up associations with past experiences, leading to new ideas and visualizations of their implementation.

Two quick mock-ups of Cardboard Orchestra

I used straws to indicate knobs. The straws reminded me of a childhood friend who is a brain surgeon. She told me how she was taught to push straws through brains in medical school, to feel the different layers and sections of the brain. Staring into the cluster of blue straws inside the box, I though about all the three dimensional optical paths possible between LEDs and photo-resistors. I saw them as neuron signals in a brain, and these straws selectively attenuating the optical paths. As I push the straw into the optical chamber, I am partially blocking light from an LED to a photo resistor. If the straws were acrylic rods, possibly finely sanded to give a scattering frost, they would light up!

Inserting Straw into Optical Box

My original optical sequencer is one channel and two dimensional. I knew I wanted to control more channels, namely pulse width, amplitude and tempo, all of which are available in my 555 circuit. I though of stacking the ping pong balls and having each LED shoot light with a wide enough beam to illuminate all four balls. Cardboard circular cutouts suspended on wires would rotate and eclipse the light between LED and photo-resistor. I got this idea from dodging sticks I used in a darkroom long ago.

Blocking 3D optical paths with straws

The 3D ‘straws in optical brain’ idea I am developing reminds me of Alexander Calder’s mobiles. I am creating optical valves that are 2D shapes suspended by stiff wires into a 3 dimensional space of light beams. I’m building this in a cardboard box, but it could be as large as a room, with big RGB spot lights shining onto huge white spheres containing photo-resistors. As the mobile pieces move, they are changing the values of the photo-resistors whose light they intercept. All the light in the room would be from the RGB spotlights, which sequence… might make people dizzy.
Folding a long piece of cardboard into a triangle makes a sturdy box and a nice slanted control panel. This is a unibody case design, very strong and sturdy. However the knob plane and lower case are not parallel. This may require a reference sheet of cardboard (called ‘anchor plate’) to be mounted underneath the knob plane. Or an anchor plate can be glued to the underside of the knob plane.

Triangular Unibody Case

Machine screws are used to make multi-turn optical valves. These can be tightly packed. Placing surgical tubing over threaded bolt will give better finger grip, feel and traction. The combination of small and very accurate is encouraging for making large complex systems, or small portable devices. It also can be used in the inner rings of larger knobs, to pack more controls per step.

Tweeking Tiny Multi-Turn Knobs

While looking for knobs to put on my optical valves I thought about kids and their blocks. Kids have little hands and play with big blocks. Big wooden smooth blocks that have weight, substance and a kind of softness, maybe even the slightest scent of the forest they came from.  There’s something comforting, even gentle, about big blocks.

Big Wooden Knobs with Notched Optical Valve

My original optical valve consists of two pieces; a chop stick for a shaft and a rectangular piece of cardboard to block the light. If I made the shaft big enough, and I drilled a big hole or cut a notch out of the side of the shaft, I could combine the shaft and light blocker into one piece.
Combining these two ideas, I though about big wooden knobs. What source of wood could they be made with?  Ah, a broom stick! I found a wooden dowel about the diameter of a broom stick, and cut 8 pieces of 4 cm length. I first drilled a hole, but wanting a bigger aperture (pathway for light), I used a mill to cut big slots. A mill is clearly beyond most people’s abilities, but it can be done with a hack saw blade.

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