Direction of motors

[Boom]

I would like to make a foldable quadcopter in X-configuration.

For the way I would like to design it all motors are spinning in exactly the wrong direction. I see that according to the specification the front left motor should spin to the the right. This pushes the front left boom to the left. The problem I have is that this is exactly the direction that the boom should fold. So I would prefer the front left motor to spin the opposite way: to the left.

Is there a simple way to reverse the direction that the multiwii board is expecting them to spin? I was thinking of simply pointing the forward arrow to the right and then switching around the pitch and roll connections between the receiver and the board. Would this have any negative effects? Are there better ways of doing it?

[bill516]

Cant believe nobody has answered you even if its just to tell you the multiwii doesnt care which way your motors turn. Now read this next bit very carefully because its really complicated. Take two of the three wires from the esc, any two and swop them over, your motor will now run in the opposite direction. See told it was complicated.

[frogstarb]

That's actually not accurate, I believe. It's true that if the motors are counter rotating each other in sequence, MWC will handle pitch, roll and elevation without caring exactly which side they're turning, but yaw is slightly different, as MWC must know which motors to spin down or up to make the machine rotate to the current side. And while you can invert the TX channel, the yaw gyro will try to compensate doing "the wrong thing (tm)" which will get your copter in a deadly spin!

I believe this is a very simple change in the code, inverting which direction each motor is supposed to be spinning (but yeah, actually making it spin one way or another is a very simple fix as bill516 explained) though I'm not equipped to tell you what that change might be off the top of my head. I just thought I'd reply to prevent damage.

[Boom]

Hehe, thanks bill, but I was refering to exactly what frogstarb meant.
According to the images I've seen the front left and back right motors have to spin clockwise, so that when they are spun up (while the others are spun down) the quad will turn counter-clockwise.

Hope someone who knows where this could be fixed in the code replies (best would be to make this switchable with a define).

[PatrikE]

Can it be as easy as using this define in config?

Code: Select all

  /********************************    TRI    *********************************/
    #define YAW_DIRECTION 1
    //#define YAW_DIRECTION -1 // if you want to reverse the yaw correction direction

Even if its under TRI it controlls Yawdirection on all nultirotors.

[Boom]

Yay, thanks!

Didn't check in the config under TRI. Now I just have to wait for my board to arrive to test it.

[lpbug]

I was looking for exactly this. Thanks for coming up with the solution- have you tested?

Thanks.