Hi,
I am trying to tune my ranger 1600. It is finaly working with arduplane. Actually it is my fourth try with ardu project and it is first model that is actually flying 
I tried autotuning and what I have noticed, I think that stabilization is reacting faster, however in stabilze or acro mode my model is rolling or pitching slowly. Roll is a bit trouble for me because I can’t flip it upside down fast enough. It is simply very stable and very slow to do roll.
How can I increase reaction speed, especially to roll faster? In manual mode it is working as it was before adding autopilot.
If you’re using autotune, have you tried adjusting AUTOTUNE_LEVEL?
No I haven’t yet. I had one day of good weather only. I thought for a glider default will be fine, but this might be a good tip. Will try when weather will be good for flying.
I have tried auto-tune level 9 week ago. It seems that servos are working more and are more sensitive to any movement, but the control in trainer/acro mode feels sluggish. FBWA mode is quite responsive, but turns are very long, I would like to make it sharper.
When I used to fly with this airplane without FC it was really dynamic airplane. I could easily flip it upside down and fly like that. With FC when I have tried that trick it was turning to slow and I crashed into the ground smashing whole interior of the aircraft 
because it took too long to turn upside down.
I have several questions:
Which parameters control roll speed in acro mode?
How to increase maximum angle in FBWA mode when turning?
Howto enable auto-triming? My model tends to rise nose up, I might level the flight controller again, but the problem is that when airplane is on the bench it has nose a little bit up so leveling it on the desk is not an option. I need to trim it in the flight according to actual behavior.
Besides that I find flying with arduplane very relaxing, especially with loiter mode and RTL. Those features are very cool and they work right out of a box 
SERVO_AUTO_TRIM=1 should take care of the trim. Fly in FBWA for a while straight and level and this will sort out most issues. Remember though that trim is subject to throttle setting. SERVO_AUTO_TRIM can be left on and should solve most issues but it will always lag behind quick throttle changes.
As for the turns and other performance we’re now getting to the more subjective side of tuning because it sounds like the plane is more or less flying well. You might want to play with ACRO_ROLL_RATE (and pitch) LIM_ROLL_CD.
Have a look at these:
https://ardupilot.org/plane/docs/parameters-Plane-stable-V4.1.7.html#acro-roll-rate-acro-mode-roll-rate
https://ardupilot.org/plane/docs/parameters-Plane-stable-V4.1.7.html#lim-roll-cd-maximum-bank-angle
https://ardupilot.org/plane/docs/acro-mode.html?highlight=acro#acro-mode
Another thought on that: The Ranger has that high mounted pusher engine. Check when you’re in manual mode if you see a big change in pitch when you add or remove power. The thrust line of the motor might not be correct and you might have to physically adjust the angle of the motor. Andrew Newton on Youtube has a few videos on that plane and I seem to think he talked about that.
Yes, I was thinking this might be physical design thing.
Thanks for this tips. I will check all this when weather allows that