Perpetual Motion

This is a spatial Bricard 6-Bar linkage that can be made from card stock, best sliced by a laser cutter like the Epilog Zing. ( http://en.wikipedia.org/wiki/Raoul_Bricard )

There are slogans on the faces. I originally designed this cardboard toy to advertise the Make Lab at our school arts festival called ArtRageous. I called it a mechanical donut, but my more artistic colleagues called it "Perpetual Motion"

Feel free to put in your own slogans!

Albertus Mus in the Discussion comments also pointed out earlier work related to these folding designs. Check out:

(1) IsoAxis ( http://www.ac-noumea.nc/maths/polyhedr/IsoAxis_.htm )

(2) Kaleidocycles ( http://www.kaleidocycles.de/ )

If you do not have a laser cutter, you can also make the toy with plain scissors. Print out on card stock for best results. After you cut out the outline, fold along all the dashed lines, keeping the graphics on the outside. Start assembling by matching up the two edges labeled ^ 1 ^ and taping them together. Continue in sequence with the two edges labeled ^ 2 ^, etc. through ^ 6 ^. You will get a tube like shape with six tetrahedrons attached in alternating positions. Join the first to the last one, to get a closed donut, and tape together the matching edges labeled ^ 7 ^. The linkage is almost ready. Flip the linkage through and tape the two edges labeled ^ 8 ^ together on the other side. The toy is now ready to keep fingers busy!

If cut by laser, the folding is a lot easier. The more accurately you make it, the better it moves.

The .cdr file (Corel Draw format) can print to an Epilog Zing Laser. If you do not have Corel Draw, you can print the .pdf file.