Armed Pixhawk 2.1 Can Spin Motor, But Not Servos

Hello! Kind of in a crisis here. I am using Arduplane V3.8.4 on the Pixhawk 2.1, however, as the title states, even after being able to fully arm the vehicle, I can throttle up and the motor spins up, but the servos on my elevons are not actuating. I have set up the servo outputs on the MAIN: 1 = throttle, 2 = left elevon, 3 = right elevon.

The servos I’m using are: https://hobbyking.com/en_us/hobbykingtm-coreless-digital-hv-mg-bb-servo-20kg-0-16sec-66g.html

I have a hunch it is something power related, or a PWM signal problem from the Pixhawk to the servo. Please let me know if anyone has any thoughts.

Hi George,

It will be good if you can provide more info on the details of the other components you are using, such as the batteries, ESCs and airframe specs.

I had the same problem with one of my quadplane designs previously, and it turned out that the problem was with the ESCs: The ESC connected to my servos had no built-in Battery Elimination Circuits (BEC), thus no power was supplied to the control surfaces. So I would suggest you either ensure that your servo ESCs have built-in BECs (if they don’t, they should have a label “No BEC”), or connect your servo ESCs directly to a separate battery (not recommended unless your aircraft can handle the extra weight).

Of course that’s only one possible problem, it could be something else I am not aware about (: