RCU Forums - View Single Post - Help electric motor size for 46 size trainer
Old 08-10-2013, 01:42 PM
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Campy
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You need to determine the weight of the plane WITHOUT the engine in it. Then determine the weight of the motor you plan to use (how many oz) AND the weight of the battery. Add this to the weight of the plane. Now you have a weight you can work with.
Figure you will need 100 - 125 watts of power per pound of weight for a 40 size trainer. MANY motor suppliers provide a "wattage" based on a particular size/pitch prop and size of the lipo (3s, 4s, etc.) If in doubt look at the HK site. Almost all of the motors listed there provide a "wattage".

Hope this helps.