Porting px4 to Align T-Rex 500 Helicopter Airframe


I’m using the blade130 as the starting point and my code is here. I don’t know this codebase so I may be doing something silly. I just naively replaced the occurrences of blade130 with align500, should the changes I made work? I did update the swash angles and servo arm scaling.

Even if the code I made does work, it is not what I would think is the final solution. What I really wanted is a gyro assisted stabilized flight mode. I’d also like to maintain the throttle / pitch curves in the radio, I think it’ll be much easier to adjust on the fly that way. How would I go about developing a mixer to stabilize the the swashplate without mangling the 4 inputs (pitch, roll, throttle) into the 4 outputs (CCPM + throttle)? I’ve been reading through the docs but I must confess I’m a bit lost.

Finally when I used the blade130 airframe on the pixhawk installed in the t-rex I noticed 2 things that didn’t make sense:

  • It would asynchronously jump out of arm condition and all control authority is lost to the swashplate.
  • It seems there is no authority to the tail rotor at all.

Thanks for any guidance,

I cannot seem to load the airframe that I have defined. It doesn’t show up in QGC. Do I need to update the GUI as well?

1 Like