The Illumicon Drawing Machine:

Unlike most drawing machines that create images by dragging a pen over a piece of paper, the illumicon makes its images by moving a miniature LED light under a camera with the shutter locked open. This captures images images such as the following:


This is something the vast majority of mechanical drawing machines can't do. To understand why, take a look at the the Cycloid Drawing machine by Mr. Joe Freedman at

It, like virtually all drawing machines, has the paper on a rotating turntable and the pen on an arm linked to the turn table through a system of gears. If a light were placed on the turntable it would produce a circle. If it was on the arm holding the pen it would make a line or ellipse. To complete an entire image the light's path must combine both motions, which is what the illumicon accomplishes by mounting the gears that move the pen on a central turntable. More than anything else, the illumicon resembles a planetary gear system.

The surfaces are painted black so that they aren't recorded by the camera during the long exposures, sometimes up to 20 minutes, required for a complete trace. The main outer gear has 150 teeth while the inner gears have 36, 60, 74 and 86 (not shown) teeth. The gear designs were printed from a free, on-line gear generator and cut from top quality birch plywood using a scroll saw. They can be used individually to produce spirograph-like patterns such as the following:


Made with the light on the outside edge of a 74-tooth gear.


To make this image, a light was placed half way between the center and edge of a 36-tooth gear.

Here the light was position close to the center of the 74-tooth gear.


If the light is placed on an arm linking two gear, truly complex patterns result.

To produce this image, the arm had one end pinned to a 32-tooth gear while the other end was free to slide through a pin on a 74-tooth gear.


More than one light can be placed on the gears to make multicolored images.

Even more colorful designs can be achieved by using color changing LEDs.


One particularly artistic technique is to halt the image capture before a complete cycle has been completed.

The following are two of my favorite traces:



To see the illumicon in lice action, please click on the following link:





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