Bonetti Machine

Topic: Physical Sciences Subtopic: Electricity & Magnetism

Case Study

of an Exhibit

by Erik Herman

Published on April 10, 2009, Modified on April 11, 2009

  • Museum: Physics Factory Focus: Science

  • Collaborating Organization(s): Altuglas International

  • People who worked on this: Brian Love (Engineer & Machinist), Erik Herman (Project Manager), Kip Perkins (Engineer & Technician)

  • My role: I oversaw the project from its inception to its completion. The idea began when, after seeing the giant Wimshurst Generator at the Chicago Museum of Science and Technology, I was having dinner at a round glass patio table (which resembled Wimshurst's disks.) What committed me to the project was when my request for two donated Plexiglas disks was answered by Altuglas International. Once I mounted the disks, a long process of experimentation took place. The project would have taken many wrong turns if I hadn't solicited the online help of an Electrostatics expert, Luiz Alberto Feijo Jr., a Physics professor in Brazil.

  • Description and goals

    The Bonetti Machine is a high voltage disk-type electrosatic influence machine. The heart of the apparatus is two 5 ft. diameter half-inch thick acrylic disks. These 1/2" thick disks rotate in opposite directions on a common axle. They sit perpendicular to the ground with a 1/2" gap between them. Two motors spin the disks up to 400rpm. Two sets of neutralizer combs and one set of collector combs allow the machine to generate 200,000+ volts and 14 inch sparks at the discharge terminals.

  • Exhibit Opened: April 2009

  • Location: Tucson, AZ, United States

  • Estimated Cost: Less than $5,000 (US)

  • Website(s):

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