| This machine manipulates small spherical rare earth magnets, slicing one at a time from the end of a long chain, moving it around a bit, then dropping it back to re-connect at the tail end of the chain. It also demonstrates a little snippet of science called eddy currents. Watch how slowly the magnet falls through the aluminum tube compared to falling through air: the falling magnet generates an electrical current in the tube, and that current in turn generates a magnetic field that opposes the movement of the magnet, slowing it down dramatically. See en.wikipedia.org if you want more. I made this machine for my father-in-law for his 75th birthday: astute viewers equipped with video analysis software and way too much time on their hands might find that the magnet drops 75mm from the tip of the slicer until caught by the lifter, and that the lifter then drops it through a 75mm long aluminum tube. These magnets are currently a popular toy, and can be purchased on the web or in stores (usually in a set of 216, which makes a 6x6x6 cube). Many different brands exist: Zen Magnets (zenmagnets.com Buckyballs (www.getbuckyballs.com nanodots (www.thenanodots.com Neo Cube (www.theneocube.com and more. I highly recommend this toy! Watch some videos at the above sites. I used a plastic drywall anchor for the main screw drive that pulls the chain of magnets through the machine. The 2 other driven axles -- the slicer and and the lifter -- are geared directly to the screw drive. (Steven ... |
