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Thread: differential ailerons

  1. #1
    Join Date
    Jul 2011
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    Default differential ailerons

    -For regular airplane with differential ailerons, connect like this:
    Rx auxiliary output ----> OSD auxiliary input
    Rx Elevator output ----> OSD elevator input/output ----> Elevator servo
    Rx Aileron1 output ----> OSD aileron input/output ----> Aileron1 servo
    Rx Throttle output ----> OSD throttle input/output ----> ESC
    Rx Aileron2 ----> OSD rudder input/output ----> Aileron2 servo
    (Note that on this mode you have to connect the rudder of your airplane direct to the receiver, thus you have to set the failsafe setting on your receiver to neutral trims. So the failsafe setting does not make the airplane to turn to any side).

    what are the thoughts on
    • differential ailerons as per RVOSD (above)
    • Y splitter
    • V tail mixer


    im not 100% sure on what to use ...

  2. #2
    Join Date
    Nov 2008
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    Default

    I think it depends on what type of plane you are setting up for. Are you flying a power plane or a motorglider? I use differential ailerons on my gliders. The complications occur when you use FBW. RVOSD won't allow me to use butterfly mixing properly. One aileron would deflect upward more than the other, and a spiral would ensue. I always deselect FBW before deploying the brakes.
    I am currently trialling a different setup with a Y lead on the ailerons connected to RVOSD Ail 1, a Y lead to the flaps directly to Rx, and RVOSD Ail 2 to Rudder. No butterfly mixing, just full flaps for landing. I haven't flown it yet.
    Last edited by ommadawn; 09-27-2011 at 05:56 PM.

  3. #3
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    Default

    Quote Originally Posted by ommadawn View Post
    I am currently trialling a different setup with a Y lead on the ailerons connected to RVOSD Ail 1, a Y lead to the flaps directly to Rx, and RVOSD Ail 2 to Rudder. No butterfly mixing, just full flaps for landing. I haven't flown it yet.
    i am thinking of a similar setup, but having a vtail mixer inbetween so that differential can still be implemented

    let me know how it goes

    also ... does RVOSD use the rudder at all ? if so how ?

  4. #4
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    Jul 2011
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    Default

    after failing miserably trying to get my OSD and Tx to play nicely i have just ended up using a Y cable for the ailerons :S

    i still dont see how or shall i say what RVOSD would do with differential's ? is it just to ease setup ?

  5. #5
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    Default

    Im missing what you want the Vtail mixer for. Differential ailerons usually are set up so that the upward moving surface has greater throw than the downward moving surface. This helps to reduce adverse yaw and also reduces the risk of tipstalls. What problems are you having with the ailerons? You need to select differential ailerons during setup, then connect the second servo to the appropriate output.
    Differential ailerons will work with RVOSD as long as you don't use FBW or any of the automatic flight modes.
    It normal flight it just passes through any control inputs. When FBW is used, RVOSD takes control, and all it does is sees what you want the plane to do, and decides what control surfaces to move and how much, to achieve the desired aircraft attitude.
    Keep at it.
    Cheers
    Frank

  6. #6
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    Default

    Differential ailerons don't work when using FBW?

  7. #7
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    Jul 2011
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    Default

    if i use a v tail mixer then i can have flaperons ..... this is what i would like to do , but you cant eliminate the 3 position switch from working the flaps on a ff8, so when you toggle the screen menu the flaps work duh, and i cant use the gear channel as its only a 2 position, double duh !

    i can have differential by means of a mechanical linkage (moving the control horn hole offset to the pivot) but its a pain to make changes ... (using Y cable)

    anyways i have gone with a Y cable and no flaps for now , the flaps are molded in the wing but i still have to cut them out and install the servo's ... i will see what landing speed is going to be like and the decide

    but im ordering a turnigy, i had a look at a friends and am going to solder a 3 position switch to the one channel, then its all sorted

    ta

  8. #8
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    Default

    Quote Originally Posted by HF_ATL View Post
    Differential ailerons don't work when using FBW?
    I had trouble using Butterfly mixing with FBW, as the maximum aileron throw was reduced on one side, so I could not get the same upwards deflection on both ailerons, and the plane would spiral. According to Alex, it doesn't handle mixing.
    Last edited by ommadawn; 09-29-2011 at 06:01 PM.

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