Hmm, what I'd do is:
1) Create new model, delete all mixes (all servo outputs will be 0).
2) With the servos centered like this, do all your mechanical 0° adjustments (servo horns straight, use ppmca if needed, swashplate flat at 0°)
3) Set your swash type in heli mix, set collective source to THR, assign CYC1,2,3 to the servo outputs in the mixes screen according to your connections, all at 100%
4) Move the throttle stick up/down, confirm all servos move in the correct direction and reverse if needed (individual servos on LIMITS screen or functions on the heli setup page), and check you've chosen the right holes on the servo horns to reach the highest up/down angles you want without having too much excessive throw
5) On LIMITS screen, adjust up/down limits of all 3 servos so that the swashplate is level at both the top and bottom end, AND you get the maximal pitch angles you want to ever reach (collective + cyclic), i.e the 20° you mentioned. Now if the mechanical part was done correctly you should have your swashplate perfectly level all along the throw of the throttle stick.
6) Now choose your first pitch curve, e.g. Curve 1, create a new mix for a free channel (e.g. CH11), assign source THR, curve 1, on heli setup change Collective source to CH11.
7) Edit the curve, starting by both end points, setting those to the max collective you want to reach (e.g. -2°/+12°), and filling in the midpoints how you'd like them
8) Center collective stick, set AIL and ELE D/R to reach the desired cyclic pitch (the 9° you mentioned) (I just tested in the simulator, D/Rs do work indeed).
In summary, now you'd have:
- Your collective range, set in 7), defined by the pitch curve
- Your cyclic range, set in 8), defined by the AIL and ELE D/Rs
- Your max angles (cyclic+collective) enforced by the LIMITS set in 5)
Now, I've had a look on the simulator and on my Futaba radio. Swash Ring actually crops the "square" nature of the AIL-ELE stick to a circle.
Let's say you move your stick fully left from the center, you did a movement with an "amplitude" of 100%. Same if you start with the stick centered and go fully down. BUT, as the stick can do a square, if you go to the lower left corner, your total amplitude movement is actually of 140%. This means that depending on the different adjustments and limits you have, even if you checked your cyclic angles at +/- 100% of every single control, you could have a servo that hits its limit earlier than expected if you bring the stick to the corner, and due to the cyclic mixing if one servo hits a limit it will affect all the 3 functions with unpredictable weird flight behavior.
Setting Swash ring to 100 will "round off" the corners, and never allow you to input more than 100% total deflection with the stick. Imagine a circle in the X-Y graph of the stick, diameter being the throw of the stick, and whenever you move the stick the output will be limited within that circle.
Actually I'll post screenshots of the Futaba, it's quite clear, I have the stick in the corner both times:
- Swash_ring_off.jpg (51.13 KiB) Viewed 26629 times
Setting lower values for Swash ring will simply make the circle smaller, but IMO as it's a hard limit it makes no sense, as you lose use of some stick throw. Say you set Swash Ring to 20, then as soon as your stick is more than 20% off center the servo stops moving and the remaining 80% of stick motion do nothing. So I'd leave Swash at 100 if used...
The next step will be to set up a throttle curve, so on the channel your ESC/throttle servo is connected to you'll want to create a mixer line with source THR, choose a curve (e.g. curve 4), long press MENU to go to the editor and enter the curve settings.
You can then add more throttle or pitch curves for your different idles the same way, just insert new mixer lines below the existing ones, again with 100% THR source, another curve do you can make it different, a switch to activate it, and Multiplex type "Replace" so that it overrides the previous one(s) when active.
There we go, only step left is setting up a gyro mix - depends on the gyro but usually easy, you typically simply would set gain adjustment on a pot (with a 100% P1 mixer line on your gyro channel) as a first step, fly and find the correct setting, look at the output monitor to see the value your gyro channel is set to, and if it's for example -42% then replace that 100%P1 line with -42% MAX. Gain will now be locked there. If you wanted a second setting sleectable by a switch - you've probably understood by now, but you'd simply create a second MAX line below the first one with the other % value, set type Replace, and select your switch.