Traditional helicopter airframe development

PX4 Autopilot Multicopter šŸ›ø
1

Hello,
I have been testing the ā€˜ā€˜Generic helicopter tail ESCā€™ā€™ airframe config since a few weeks and I have some issue and question.

First of all Iā€™m using a SAB Raw 580 kit as a base combine with some 3D printed part to build an autopilot + companion computer setup.

Due to my kit using a geared belt servo to drive the anti torque, I already know that the firmware (main branch) wonā€™t work without modification or adjustment.

Here my questions/issues:

  1. Since my airframe is different from ā€˜ā€˜Generic helicopter tail ESCā€™ā€™.
    How can I add a configuration that use an anti torque driven by the main motor driven by a servo to the craft

  2. I see that there is no governor mode.
    Is there currently any work to use the RPM wire from the ESC to maintain the rotor head speed?

  3. On the ā€œactuatorsā€ page of QGroundControl to setup the swash plate servos you need to setup an angle and an arm length for each servo. Values description doesnā€™t really explain the context of their use case, and actual illustration could really help.

For example for the servo angle, do we measure the servo angle or the servo position on the swash plate ?.

The description of the value says that 0 is facing X positives but in which direction 90 is facing, Is it Y + or -?

Also, for the Arm length I suppose its the distance between the pivot of the servo and the pivot of the swashplate link. In my case the value would be18 the max value is 10 how can I increase the ceiling?

Note that this project is used for my school course validation and that Iā€™m mostly a dev so Iā€™m learning PX4, engineering, math, and drone related stuff progressively.

2

Today Iā€™have notice a few thing while playing with the actuator settings:

  1. Using the reverse range have a wierd behavior (check video).
    Servo 2 need to have rev range enable to have the correct behavior but playing with roll axis make the cyclic pitch and Pitch axis roll

  2. is there any way to isolate the magnetic field that servo 3 generate ? The stock FBL emplacement is kind of nice so i wish to avoid relocation