I want to subtrim my yaw servo to 1650 because that is the place where it's centered.
I get only half the trawel on the motor if it's centered at 1500.
because of the servo horn. I put in new values on rc7 1250, 1650, 2050 but i see no difference when i boot my apm up when i Arm it centers but i hawe put subtrim on my radio to 1650.
in my mind i should set min max mid value for servo somwhere and set radio to standard values. and apm should handle the centering of my servo.
or I just set the motor mount leaning to the side at 1500 and let the flight controller hgandle it inflight but that makes no sens because it's off by 150
There is noone who knows how to subtrim yaw servo?
I made a testflight it did not work with subtrim and mission planner rc vlaues the same.
Changed subtrim to 0 in radio kept subtrim in mission planner the tri flyes fine. But now i haw absolutely no clue if 1119 is translated as 1300 or 1119 and 1911 as 2000 or 1911.
if i look in log I will see. but now where are the radio calibation values?
because the calibration values are stored in the servo trim values. this makes absolute no sense to me.
I'm not exactly sure what point you're trying to make here. In general, with APM and arducopter, you want your radio sending 1500 at neutral for your flight channels. You should also if possible have your radio's flight trims disabled. Use the APM's auto-trim feature to make sure the copter hovers well with neutral inputs on the radio.
The yaw servo on a tricopter is controlled by the algorithms of the APM with only an indirect link to your radio's sticks.
The neutral point once properly configured should place the tail motor at a slight angle to counteract the imbalanced torque of the three motors (depending on the rotations and combinations of standard/reverse props you're using).
I normally adjust my mechanical linkages such that the APM when armed and sitting on the ground has the motor at approximately the same angle as it would in a hover. It will fly fine if the linkages are anywhere near that, but may yaw some on lift-off it they're not close. Being within one tooth of your servo's output shaft should be plenty good.
There is simply no documentation on how to impliment tri yaw servo. And I would like to hear from a developer the correct way to implement yaw servo.