The Art Of Motion Control

Sisyphus III

Third generation sand plotter for Technorama -- The Swiss Science Center -- Winterthur, Switzerland

"Mathemagie" opened on September 19th, 2003. This is a large group of permanent exhibits that touch upon diverse mathematical themes. Sisyphus now toils upon his perch, in the heart of the space.

Videos created by Thomas Hofer for Technorama

The poster for the MatheMagie show. "Spuren" translates to "tracks" or "traces."

Watching some of the first paths, on the night of the "vernissage:"


The real view looking up at the underside, from first floor (compare to virtual, below):


Project history:

In mid-May, 2003, I received a phone call from the director of Technorama. He was interested in the possibility of permanently installing a sand plotter as part of a large mathematics exhibition. The time frame was extremely tight-- the exhibition was set to open in less than four months time. I flew to Zurich in June for a two day visit, and after seeing the intended site, proposed a much larger version-- 3 meters in diameter. After several weeks of technical analysis, the highly capable staff at Technorama and I agreed upon the structural design and components, to be fabricated in Switzerland.

The site is suspended within a large opening between the first and second floor exhibit spaces:

from above

from below

Virtual models I constructed during the design and planning phase:


Animation of virtual model, as seen from below (2Mb)

Photos of fabrication progress in Technorama shop (Aug. 15):


Testing new acceleration profiles on a variety of computers at home, prior to sending them off for testing on the new mechanics in Switzerland (Sept. 7):

Heinz and I worked back and forth over the 7 hour time change pretty much nonstop during the short two week period we had remaining, as the electromechanical construction neared completion. I made a number of improvements to the software (adjustment of the ball's speed depending on how far out from the center it is, and smoother acceleration / deceleration allowing much more rapid path completion). He affixed the membrane and attached the wooden ring on Sept. 11, and we were ready for the first real test path:

from AutoCAD in my office------->to Technorama's shop:


Then for some fun-- test paths: (9/12-13, 2003)




early 2004: