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Archive for April, 2007
Posted by Bruce Abbott | Apr 10, 2007 @ 04:19 AM | 11,363 Views
After burning out the second motor in my A10, I decided it was time to go brushless.

AFAIK, there are only two manufacturers of 12mm motors, Feigao and Medusa. I chose the Feigao 1208425 (5800Kv) because its Kv is closest to the original brushed motor, and the price is reasonable. The total cost of two motors and controllers was US$99 (motors from Air Craft, controllers from United Hobbies).

Before installing the new motors I tested one in a bare EDF50A fan, and compared it a stock unit. The results were not very promising:-

 Make    Model  Volts  Amps   rpm  Thrust(g)
  GWS   CN12RLC  7.01  4.77  31500    90
Feigao  1208425  7.01  4.95  31740    92
The Feigao used 4% more power, but only managed 2% more thrust . Oh well, at least I don't have to worry about burning them out...

However, it's not that bad because the brushless 'upgrade' has a bonus, it's a lot quieter . Whereas before the A10 sounded like a pair of dust busters, now it's less whiney and more 'jet-like'. At cruise throttle the motors are almost inaudible.

The only down-side is that my old Polyquest 880mAh Lipos are no longer good enough, because their voltage sags too much causing one controller (but not the other) to cut out. This introduces differential thrust and makes it hard to steer straight. Luckily I also purchased a Hextronik 12C 1000mAh 2S Lipo, which holds its voltage well and also gives longer flight time.

Also today I discovered that my A10 can R.O.G. despite not having any wheels! So all in all, even though going brushless has barely improved the model's performance, I'm happy with the results .