Motors for Quadcopters

Hi,

I am looking to make a quadcopter as my university project and I kinda run in to some problems deciding which motor I need to choose. I was thinking to choose brushless motors as they are more efficient and they give more RPM.

HOwever, my professor says that there's no point using brushless/stepper motors as u can get the same RPMs using brushed motors and its the same thing.

Hence, can anyone please guide me which motor is best to use and why should I use brushed or brushless motors.

I shall be very glad if someone guide me through it.

Thank you :)

If your professor is the type to look at you and say this answer is more right than that answer and not tell you the reason why, DO AS HE SAID.

Otherwise impress him.

There is no point to stepper motors unless you can convert it to an induction motor.

Brushless is another matter.

Some brushless motors like induction motors go faster or slower depending on the frequency of the input not the power of the input so they maintain power as the rpms go up or down.

There are small induction motors that will fit on a quadcopters and work this way.

Joe
Willard2.03 years ago
I would look into using brushless motors.  It is much easier to find speed controllers for brushless motors than brushed (If you plan on using an RC controller with it).  If you plan on building a custom controller, then brushed is easier to control. 

Don't go with steppers, you don't need precise control, you need general control and reliability.

IMO, the main reason everyone goes with brushless outrunners is the torque they have.  You can direct drive the props and you don't need a heavy or fragile gearbox. Brushless motors also tend to be lighter, and with a quad, weight is everything.

The AR Drone uses small high RPM brushed motors with a gearbox.
http://ardrone2.parrot.com/

The traxxas QR1 uses direct drive brushless motors. 
http://traxxas.com/products/models/heli/6208qr1

There are pros and cons of both, but in my mind, there are far more pros for using brushless motors.
nicholsmom3 years ago
We never had such cool projects when I was in college :/

I don't know about the motor you should use, but I do wonder what you think of your professor. If you had a project in another class that overlapped his area of expertise, would you go to his office to solicit his advise? Also, how much of your grade would be effected by NOT taking his advise? If you respect his opinion, than take it, if not (and it won't hurt your grade), then do as much research as possible (mpilchfamily, below, gave you a good starting point) and wind up with a very cool quadcopter :)
Most quadro copter motors i've seen are brushless. Overall brushless is better (IMHO) for use in a quadro copter. But check the pros and cons for yourself and make up your own mind.

http://www.dynetic.com/brushless%20vs%20brushed.htm