I've got my T-Rex 450 all set up. I loaded the stock software with the stock PID values. It held stable fairly well, but I got no rudder when I moved the stick.
Then, I changed the P values for rate and stabilize on the rudder. I got a movement, but not much, and I got more unwanted movement (oscillations) than desired movement. That flight ended with a $100 tree landing.
So does anyone have a good, solid set of PID values for stabilize mode on their TRex 450? I get the distinct feeling that working this from scratch will be a recipe for bankruptcy, and I'm already working on a college student budget. Any help would be most appreciated.
The stock PIDs should work ok. Are you using an external gyro? If yes, you should be sure to click the external gyro check box in MissionPlanner's set-up screen, on the Heli tab.
If you're not using an external gyro I'm not sure exactly what values will work. Robert Lefebvre should know. You can find him on the monster trad heli thread.
Yeah, external gyro or not?
I'm using the built-in gyro, Yaw Rate P is 0.350, I is 0.015, D is 0.03 IIRC. Yaw Stab P is I think 2-3 (this is less critical), and I is zero.
I'm also using the built-in gyro. If you could, please confirm those values, and I'll try them once I get the heli back up and flying.
Initially, I used the values that flashed to it from the mission planner at the time, and the values weren't the same as the ones you listed. The heli held attitude stably, but control inputs would not generate yaw. Increasing the stab and rate values to higher values increased responsiveness, but induced instability. I'll use the values you provide on my next flight, and see how things go.
For reference, I'm using a T-Rex 450 Pro V2. It came out of the box flybarless, with their 3GX module (now sitting off to the side, replaced by ArduPilot).
Also, some background on me: I'm not a fantastic R/C pilot. I've got about 200 hrs in simulators, and about 20 minutes in the real world flying anything. I'm entering the hobby because I'm an electrical engineering student, and R/C helis (and ArduPilot in particular) provide an ideal test bed for non-linear intelligent controls projects. I'm hoping to do something interesting with the controller for my senior design class.
I really appreciate all the help here. I've already learned tons just lurking here on the forums. Hopefully, I'll be in a position to start contributing myself soon.
I have the T-Rex 450 Pro V2 as well. How is your progress on it?