Comments by "TheEvertw" (@TheEvertw) on "I 3D Printed an ELECTRIC MOTOR FAN" video.

  1. Looks like your impeller only outputs a fraction of the volume of air compared to the regular fan. Also, the shape of your impeller is optimized for when the engine is moving fast through the air. While stationary, it will not accelerate the air efficiently: the steep starting angle of the blade forces the air to accelerate very quickly when stationary, causing a large drop in pressure behind the blade that slows it down and wastes a lot of energy through eddie flows. In fact, the impeller is designed to maintain pressure whilst simultaneously slowing the air down, the opposite of what you want to achieve in your bench test, as you want to accelerate air. That is why you also see this configuration in turbines where water flow is converted into electrical energy. When stationary, the fan might be more efficient when you run it in reverse.
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