4
$\begingroup$

While looking up information for the right propellers for my quadcopter, I realized that they had different orientations i.e. Clockwise and Counterclockwise. On further research I found that all multi-rotors have different combinations of these orientations. So my question is WHY? How does it matter if the propeller is turning clockwise or anti-clockwise?

$\endgroup$
4
$\begingroup$

This has to do with the torque, or moment, the rotors induce on the body of the quadcopter/multirotor. If all of the rotors were to spin the same direction they would all induce a torque in the same direction causing the craft to yaw. Of course this is undesirable for many reasons. By spinning half of the rotors the opposite direction the torques are theoretically canceled preventing the craft from yawing.

$\endgroup$
  • $\begingroup$ What about a tri copter? How is not so compulsory for a tri copter? $\endgroup$ – Chandough Jun 2 '13 at 6:39
  • $\begingroup$ @Chandough This would be better as a separate question, but as with a standard helicopter, a tri-copter can't balance the torque effect of the odd number of otherwise identical props, so would need to correct for the torque effect some other way (for instance with a tail rotor in the case of a helicopter). $\endgroup$ – Mark Booth Jun 2 '13 at 10:38
  • 2
    $\begingroup$ @MarkBooth Has anybody already tried a tricopter with one big rotor and 2 smaller ones to balance the torque? $\endgroup$ – ott-- Jun 2 '13 at 14:19
  • $\begingroup$ At ICRA 2013 I saw a pentarotor configured like a quadrotor with an additional large rotor in the middle. The point was to use the middle rotor for thrust and the others for vectoring. I have not however seen anything like what you are talking about. $\endgroup$ – DaemonMaker Jun 2 '13 at 16:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.