We are trying to power this motor with this motor driver , using a 11.1V 2.2Ah lithium-ion polymer battery.

(We're in over our heads with this and really need the help)

We checked with the company (E-flite) and the motor is definitely DC -- we're a bit confused as to the purpose of three wires, and how we should connect them to the motor.

Any help would be appreciated.

  • 3
    $\begingroup$ No need for the long thank you -- it adds to the noise (I've removed it). Your upvotes/acceptance tick are good enough thankyous for us -- and the existence of your question helps the site grow; thank you. And welcome to Robotics Stack Exchange :) $\endgroup$ – Manishearth Nov 19 '12 at 18:46

The motor you have there is a Brushless DC motor. It's still technically a DC motor, but you won't be able to drive it by plugging it into a battery, or even into the driver you linked to. You need a driver specifically for brushless motors that can drive all three wires correctly.

Brushless motor driver]

Something like this Electronic Speed Controller will drive it pretty well:

Electronic speed controller

You connect the motor to the 3 wires, and the power to the two wires. The little 3-wire connector normally goes to a Radio Control (RC) receiver, plugging into the servo socket. It accepts a PWM signal just like a normal servo.

  • $\begingroup$ What if we really really really wanted to use this motor driver? Alternatively, what if we used the ESC, but wanted them controlled by a PI or Arduino or beagle board or something (Not RC). How would we do that? $\endgroup$ – Olly the idiot Nov 19 '12 at 21:07
  • $\begingroup$ You either need to change the motor to a Brushed DC motor. Or you need to change the motor driver to a Brushless motor driver. You could easily drive the ESC from an Arduino. It just needs a PWM signal. $\endgroup$ – Rocketmagnet Nov 19 '12 at 21:40
  • $\begingroup$ To re-itterate what rocketmagnet said, you listed a brushless motor (3wire) and a brushed speed controller (2wire) - they both need to be brushed or brushless. Both versions (brushed or brushless) need PWM signals to operate, which an arduino can easily provide. $\endgroup$ – Spiked3 Nov 20 '12 at 0:41
  • $\begingroup$ Okay thanks for pointing me in the right direction. For the benefit of myself and future readers, can someone explain the difference between Brushed & Brushless motors, why are there a different number of wires? $\endgroup$ – Olly the idiot Nov 21 '12 at 21:58

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