Who does this?
This is an electromagnetic motor which my kids and I created from scratch. By using interesting shapes, painstakingly wrapping the electromagnets, and minimizing exposed wires, we tried to make it as attractive as possible. The project is representative of my mechanical savvy and imagination.
• From the negative battery connection (rightmost wing nut), bell wire is coiled around the first electromagnet.
• Electromagnet wire goes under the base and connects to a machine screw holding the brass brush.
• When the rotor assembly turns, the brush periodically touches brass contacts on the commutator.
• Commutator contacts connect to the brass spindle, which rests in dimples of the copper support.
• Wire connected to the support wraps around the second electromagnet. It then leads to the positive battery connection (wing nut hidden from view).
If the rotor assembly is nudged in a clockwise direction (as viewed from the top), the circuit is completed when the brush touches one of four commutator contacts. At that instant, the electromagnets engage and attract the metal rotor blades. As the blades move toward the electromagnets, the brush loses touch with the commutator contact—allowing rotor momentum to continue until the brush touches the next commutator contact…and so on. The speed of the motor can be optimized by rotating the commutator on the spindle.