EISCO Electric Motor Demostration 2 Pole, 3 4 Pole Aramtures.

Very disappointing. I bought this for a child of a friend of mine. This kid has a budding interest in engineering and I thought for $95 I could get him a nice demo of how an electric motor works. I was wrong - he and his father were unable to get it working, and they live 1200 miles away from me. Since I'm an electrical engineer who works with electric motors and drive systems for a living, I was determined to see what was wrong so I bought another one. Mine arrived broken (the acrylic plastic which forms the bearing for one side of the rotor was cracked all the way through at one mounting point) so that the rotor was out of alignment and would not make a full turn without hitting the stator. After I fixed that, I found that the motor would not self-start at any reasonable current and even with a helping twist, required 4 amps to continue running. At this current, the stator coil became VERY hot. In summary, this is a very poor design. They should have used real bearings, machined the rotor and stator iron (they are very crude castings) so that the gap between them could be made smaller, and provide a much better magnetic circuit path from the stator magnet to the stator "arms". The arms should NOT rely on the flimsy plastic base for proper spacing and placement. I would also suggest that this should be made as a permanent magnet brushed motor, rather than an archaic series-wound motor which also ends up causing complex torque vs speed and torque vs current behavior which is not a good starting point for learning. Costs $95, looks like it should cost $10, and is basically worthless for its purpose.