These results are here for people's convienence. For full details, Please see my article in the July 2009 RC Micro World (www.cloud9rc.com) E-zine.
Tradeoffs and Comparisons
When evaluating motor performance it is important to take the weight of the motor and motor mount as well as the required battery into account. If a motor develops high thrust relative to its weight but also has higher amp draw that requires a higher capacity battery, then the additional weight from the battery should be included in the comparison.
The table above summarizes the motors reviewed in terms of the total cost and total weight for the motor, the required cell, and the motor mount if not built in. Also listed is the Full River (FR) cell required to support the motor’s amp draw. All comparisons are for a 5x3 prop. The table also summarizes thrust (from a 5x3 prop), amp draw, thrust-to-weight, and the full throttle C-rate that the required cell will be discharged at. The thrust-to-weight is computed using the total weight of the motor, motor mount, and cell to put all motors on an equivalent basis for comparison.
It is obvious from the table that the LCD motor is the least expensive on a total cost basis, and is also the heaviest on a total weight basis. The LCD motor also has the lowest thrust/weight metric and the highest discharge C-rate, meaning shorter flight times. The total weight of the AP03 7500Kv motor is virtually identical to the MM mild wind motor. And, their thrust/weight ratios are also virtually the same. The total weight of the AP03 4000Kv is the lowest, and it has the second highest thrust/weight ratio. If used in a sedate flying plane the 4000Kv could be a nice light-weight solution.
The MM hot wind motor has the highest thrust/weight ratio by a fairly wide margin. It does cost more, but the way it stacks up against newer motors is a testament to how spot-on its tradeoff between thrust and amp draw has been since it was introduced three years before either the LCD or AP03 motors. For performance oriented applications requiring a bit more thrust than the AP03 can deliver and a low total weight the MM hot wind is still the king of the hill.