It appears so many students must be building the Build Simple Electric Motor project but I have to wonder if they are running into the problems that students had in my classes. The most common problem is not scraping the insulation off the wire well enough and the next problem is the gap between the outside of the coil and the top of the magnet.
For sure the gap cannot be so small that one side of the coil hits the magnet as it turns but if the gap is too large probably an 1/8" of an inch or more the motor will not run. Ideal would probably be about 1/16".
The gap is too small between top surface of magnet and bottom edge of coil, when the coil is completely vertical it will strike the magnet.
In this motor the coil magnet gap is too large and the motor will not run. Another shim under the magnet should fix the problem.
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