The idea of the project came about as I have always been inclined towards exploring various possibilities using light source. My very initial project as an engineering student involved making a rotary clock using LED’s.
This project aims at making Mechanical structures which create images spatially and temporally using light as the drawing medium. The concept is based on the phenomenon of persistence of vision, which states that the perceptual processes of the retina of the human eye retain an image for a brief moment. Persistence of vision is said to account for the illusion of motion which results when a series of film images are displayed in quick succession, rather than the perception of the individual frames in the series. Taking advantage from this phenomenon I intend to create light drawings using individual LED’s to create a specific path. The project aims at creating light drawings by making quick motions in space using LEDs as the light source.
The second prototype was to experiment with different types of mechanisms to create interesting patterns in light and colour.
After creating these initial prototypes the next task was to think about the final drawing that I wanted to create. After having spent some time trying to think of what I should draw, I decided to concentrate more on the mechanism and let the drawing be unpredictable.
This led me to think of a light sprirograph, and thats what I ended up making. I got the main inner gear and the other rotating gears laser cut at AMS. I made the gears using a trial version of software called Gear Factory, which is a plugin for AutoCad. It allowed me to make the gears easily only by specifying the pitch and the number of teeth for the gear.
The image below shows all the gears cut out from a 1/4″ Plexiglas. I had kept holes in teh gears so that I could position LEDs at different places to get different results.
The image below shows the entire setup with the central gear being powered of a regular DC motor. The speed of the motor was controlled using a regular potentiometer, along with a PNP transistor. One of the major problems here was to make sure that the motor was fixed exactly in the centre of the inner gear.
Also The whole idea of having the LEDS movable did not work out well, as the centrifugal force was too high and would pop out the LED holders very quickly, so I ended up sticking the LED & battery holder directly onto the gear.
The following image shows only the green LED with a slow shutterspeed capturing the entire spiral.
Using only the red and yellow LEDs gives a different result.
And this one is with all the LEDs together. 🙂