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Mechanics and Construction => Mechanics and Construction => Topic started by: roboninja93 on December 20, 2011, 07:50:33 AM

Title: quadcopter build
Post by: roboninja93 on December 20, 2011, 07:50:33 AM
is it possible to make a quadcopter using brushed motors and motor drivers??
usually brushless motors with esc are used so is it practical using motor driver with brushed motor?
thanks
Title: Re: quadcopter build
Post by: rbtying on December 20, 2011, 01:13:15 PM
Brushed motors, at reasonable cost points, tend to produce less power per weight than brushless motors; as the motors (via the propellers) provide the entirety of the lift for a quadcopter, it is generally more cost effective to go brushless, especially considering the low cost of brushless motors and ESCs.
Title: Re: quadcopter build
Post by: roboninja93 on December 21, 2011, 12:35:09 AM
Brushed motors, at reasonable cost points, tend to produce less power per weight than brushless motors; as the motors (via the propellers) provide the entirety of the lift for a quadcopter, it is generally more cost effective to go brushless, especially considering the low cost of brushless motors and ESCs.
Thanks for the reply...i am on my first quadcopter project and want to spend cautiously... i have brushed motors 12V of 20000+ rpm and draws current of 5 to 6 amp(measured it by a multimeter by connecting d motor with propeller to an eliminator) and can manage the motor drivers... i plan to use avr atmega 8 to control the drivers... so is it practical so go ahead with this or brushless motors are necessary?
i have another question
how do we calculate the thrust produced by the propeller given diameter of the prop?
Title: Re: quadcopter build
Post by: rbtying on December 21, 2011, 02:58:06 PM
The key factor here is thrust-to-weight: how heavy are your motors?

And thrust can be theoretically calculated by looking at the air displaced, but it's easier just to get a prop and measure the force (using a scale or anything like that)
Title: Re: quadcopter build
Post by: garrettg84 on December 23, 2011, 02:58:50 PM
Another thought on the brushed motors - the brushes wear out. They also tend to generate more heat. Brushless motors really are designed for this kind of continuous movement.