Inverted Motors - Crazyflie 2.0

[shreks7]

Hi,

As part of a project, we're trying to build an inverted drone that can carry higher payloads with Crazyflie.
(I know there is a big debate about whether it should be inverted or not, but in the given circumstances lets assume it has to be).

We started by replacing the standard motors with larger motors and a bigger battery.
The drone works perfectly without inverting the motors with this configuration and gives about 10-12 min flight time.

After inverting the motors (please note we didn;t invert the drone), the drone starts spinning in its position. So we decided to flip the yaw by looking under the hood. We changed the powerDistribution function in the power_distribution_stock.c file. We changed the original from -

Code: Select all

  motorPower.m1 = limitThrust(control->thrust - r + p + control->yaw);
    motorPower.m2 = limitThrust(control->thrust - r - p - control->yaw);
    motorPower.m3 =  limitThrust(control->thrust + r - p + control->yaw);
  motorPower.m4 =  limitThrust(control->thrust + r + p - control->yaw);

to

Code: Select all

 motorPower.m1 = limitThrust(control->thrust - r + p - control->yaw);
      motorPower.m2 = limitThrust(control->thrust - r - p + control->yaw);
      motorPower.m3 =  limitThrust(control->thrust + r - p - control->yaw);
      motorPower.m4 =  limitThrust(control->thrust + r + p + control->yaw);

The drone doesn't spin anymore, however, it only takes off to less than an inch. Increasing the thrust doesn't help.
The propeller configuration is inverted (M4&M2 are CCW and M1&M3 are CW).

Does anyone know how can we get crazyflie to fly with inverted motors?

Image -

Thanks ! Hoping to solve this soon.

[arnaud]

Hi, Nice setup!

It looks like you did not inverse the propellers. The propellers are not efficient when run up-side-down so you should turn them around and you will get much more thrust. You might have to modify a bit the PID parameters since you changed the position of the center of mass.

[shreks7]

Hi, Nice setup!

It looks like you did not inverse the propellers. The propellers are not efficient when run up-side-down so you should turn them around and you will get much more thrust. You might have to modify a bit the PID parameters since you changed the position of the center of mass.

Thanks, inverting the props was the key! Now we need to get it under control, it is going wild even with a flow deck on it.