How to implement flaperons with crow and normal flap functions

so i’ve got my full span flaperons set up. the flap channel is mapped to a three position, so it deflects half way down at the center position and full down with the lowest control position. I don’t actually need that intermediate position, but would really like to have a combined crow AND flap where the three position center would be clean, up position is full up ground braking, and down is full flaps. I should still have enough aileron authority for roll control. Can this be done?

The documentation mentions crow but it seems to be an either-or deal. I want both. didn’t see this being discussed here either.

to clarify i have one servo per side controlling a full half-span control surface.

You should be able to setup using this page.

https://ardupilot.org/plane/docs/differential-spoilers.html?highlight=crow

You can set the second option bit ‘Progressive crow’ this gives no flaps at minimum, flap only at mid and crow braking at full. You could us a transmitter mixer to map that how you described.

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i came across that page twice but never thought it would apply. i will look into it again, thanks

I implemented this option with success following the indicated page instructions on Arduplane 4.0.5. Just stick to them and you will have success.

good news. tho, did you implemented a four-servo four-piece classic full house? I haven’t got around to try it myself but my setup was two-servo two-piece…flap/spoileron.

Ooopps, you are right! My setup is the full 4 servo variant consistent with the crow flaps documentation.

To avoid confusion I would avoid using the key word “crow”, which only applies to 4 control surfaces on the wings. With 2 control surfaces, you have flaperons. So the correct page for the Arduplane setup is:

https://ardupilot.org/plane/docs/flaperons-on-plane.html

Now the only thing that deviates from the standard in your setup is that you have the sequential PWM values mapped as 0 (flaperons are angled up),
1000 (flaperons are neutral), 2000 (flaperons are down). So you would physically configure your servo linkages to reflect the above response (adjust them to be flush/neutral when the switch is in middle position).

With the above setup, if you operate the flap channel only manually from your transmitter, I think you would not have a problem. However if your flight controller will automatically control the flaps through the mission (not sure if possible), then ArduPlane will consider your cruise (flap neutral) setting with the flaps angled up / in spoiler configuration, which is not right.

The crow flaps settings and responses are a little confusing in the documentation, but if you read them carefully, you can see that the effect you want to create is “mixer addition“ of the inner and outer control surface responses for the progressive crow flaps option. The mixing would have to be done within the Arduplane firmware not on your transmitter and I think Arduplane does not support mixing within the firmware.