So I havent been able to test fly yet but I plugged in your parameters and have been doing some bench testing and the yaw was definitely reversed. Also the increased P made my transmitter much more responsive solving that issue.
My only concern that I have seen on the bench is the not returning to center when it is armed. Do your guys’ tris return to center when bench testing? I feel like it should as there are no outside forces acting on it to cause it to correct one way or the other.
It really depends on the servos. Digital ones will normally return to center. Analog won’t. But it really doesn’t make any difference**. Take the props off and arm it and start it so the servo is active and the motors are running. Then holding the copter in your hands, yaw it back it forth. You should see the tail servo correcting for yaw. If it does, chances are it’s working.
Depending on which way you got your tail prop turning, and whether or not you are using counter-rotating props on the wing, the actual trim for zero yaw will be off to one side and not in the center.
**Steve, I would like to clarify what I mean when I say “doesn’t make any difference”. If the tail is out of hover trim on liftoff on your Tri, and the yaw PID’s are set right, the gyros will determine that yaw has started on liftoff and immediately compensate for it, and steer the tail to the correct position to stop it. You may see just a tiny yaw on initial liftoff, but then it will “lock the tail”.
I feel it’s best to trim the tail with the mechanical linkage so it is in the correct torque compensation position for hover with the servo centered at 1500ppm. But that’s not absolutely necessary since it takes more servo travel for yaw one direction than the other anyway. One direction you have torque helping to yaw. The other direction is anti-torque. Normally, the tail rotor will be tilted slightly left (looking from behind) in hover using standard tail rotation with counter-rotating wing props.
Well I am happy to report with your PID settings and little extra tuning, everything is working great! I ran some alt hold and auto tune sequences and had a decent flight!
However after tuning I was just hovering testing out the ALTHOLD and suddenly one motor shut off, the left one. Does this happen when the batteries are low? I probably flew for around 30minutes and the batteries were getting low. I have the telemetry log from the flight if you would like!
It’s possible your ESC shut the motor down due to low voltage. But I would more suspect an ESC glitch/failure. I guess see if it runs again after you charge up, and if it does, try it again. Check your documentation on the ESC’s you have and see if they have a low-voltage shutdown. If they do, disable it and use the Ardu system for low battery failsafe instead, which will just land your aircraft instead of shutting down motors.
Steve, keep us posted on your progress with your project. I always like Tri’s instead of quad rotor, hex rotor, etc… So it’s always fun to see somebody build up a new design.
Awesome, sounds good. I will try to get an update and some video of it flying soon. Thanks for the help so far! I am sure I will run into stuff into the future.