The new propellers was a success

Last night I tried out the new 8 inch propellers along with a fresh motor to replace the last faulty one. The x550 now spins like a cat and flies like a bird. I trimmed the flight controller for the new propellers, which wasn't all that much to change and it's very stable.

After the basic trimming I started working on navigation and RTL (return to launch). These also has a set of P, I and D parameters for navigation. There is a good guide over at the ArduCopter wiki. However, I didn't have much success in trimming the RTL and the x550 always overshot or navigated wrong. Once both batteries were drained, I figured out that I'd trimmed using wrong parameters, dooh! I had been trimming the HLD_LAT/LON instead of LOITER_LAT/LON. Will have to do this at some other point where I can find a good field to try it out at.

Link to the guide: https://code.google.com/p/arducopter/wiki/AC2_loiter_PID

It has taken to the skies

 

[spot the shadow from the quad down to the right]

 

After painstakingly tuning P, I and D parameters in Mission Planner, it can now fly. This is a configuration part that I wasn't aware of until a few days ago, when I didn't understand why it was way too wobbly and always crashed. The reason was that my PID parameters was offside given the model, motor and propeller size I have. After some tuning using this guide, I was able to get it stable. There is still far to go when it comes to more autonomous flight but.. it flies!

Link to PID tuning guide.