Trying to setup my Vtail mixing based on the following procedure of the wiki:

Setup your transmitter with no vtail mixing

  • Set both RC2_REV and RC4_REV to 1 and KFF_RDDRMIX to 0.5
  • Start by setting VTAIL_OUTPUT to 1. In later steps you may adjust this to 2, 3 or 4.
  • Put your APM into FBWA mode
  • Pitch up the nose of the plane observe what happens to the vtail
  • If the two vtail segments move in opposite directions, then change VTAIL_OUTPUT to 2, and try again.
  • If the two vtail segments move in the same direction, but the APM is correcting the pitch in the wrong direction (both segments are moving up) then change RC2_REV to -1
  • Next try rolling your plane to the right. The two vtail segments should move to try to turn the plane left (to correct for the right roll). If they move in the wrong direction then set RC4_REV to -1
  • Now change to MANUAL mode and adjust your transmitter reversals for channels 2 and 4 to produce the right movement in MANUAL mode.
  • Finally adjust the KFF_RDDRMIX to a value that gives the right amount of rudder movement for coordinated turns on your plane. This may require some inflight tuning. A initial guess of around 0.5 is likely to work for most planes

In the above step by step procedure, I am fine with all of the steps colored in green. I am blocking on the step I colored in red, because this explanation is not unambiguous to me : what means exactly "the two vtail segments should move to try to turn the plane left"  : does this really mean that the whole plane should turn left (and thus the tail should move right) ? or does this really mean that the tail should turn left (and thus in fact the plane should turn right) ?

Thanks for a clarification (and maybe to adapt the wiki to also make it clear for other dummies like me)

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  • MR60

    Still nobody to answer this question? I am not the first one to use the APM software on a Vtail plane or am I ?

    • Hi Hugues,

      Did you manage to make it work? I am also thinking in using Talons for my mapping missions

    • MR60

      Hi Jesus,

      Yes , I made it work with great fun. Take a look at the video in my blog here:



    • That's great.

      Hughes. Would you recommend it as a aerial survey platform? Would a NEX5 fit inside?
      Would you have the bay dimensions?

      I have read that stall speed is a little high. Is it true?

      Sorry for the bunch of questions. I am deciding between this and the bormatec maja!
    • MR60

      About the stall speed : yes with the wing extensions I can fly at really low speed. I practically would say less than 20km/h but no exact measure.

      It can also land on really short distances by landing in a kind of cork screw pattern. I was first thinking of using a parachute to land in small areas but now that I've seen how short landings are possible, no more parachute needed :)

      The only thing  : I ripped off my front landing wheel at the thrid or fourth landing. It just does not hold in place. So I decided to remove it and place a foam piece at its place, that I will replace once in a while, after it gets too damaged. Or, I'm thinking also about a 3D printed nose piece that would integrate gliding rails on the bottom of the fuselage.

      A NEX5 fits fine inside, yes. The smallest dimensions of the area where you could place your NEX5 are : width = 8 cm / length = 12,5 cm / Lens hole = 5 cm diameter / Height : 9,5 cm.

      ABout the length, you have in fact the whole inside length; so when I say 12,5cm, this corresponds to the "zone" that is obviously meant in the plane's design for your camera.

      And certainly Yes it is an aerial survey platform!

    • Moderator

      If you have the wing extensions it really tames the Talon. Its a great platform, I love mine.

    • Gary.

      I sent an email to ckaktor to see if the sell it. Their webpage seems like not updated etc.

      Will see if they answer me. Do you know other place to buy it?
    • MR60

      get it at

      They also selll the optional landing gear. I use only the plywood part (not the aluminium legs) on which I screwed the hook for the catapult.

  • Hmm. I set my rudder up to do a coordinated turn...

    The way the Wiki puts it, sounds like I've been doing it wrong. 

    • MR60

      Interesting link,thx. However the wiki setup procedure is still very ambiguous.

      It would be easier to tell , with a drawing , how should the vtail surfaces be positioned when the plane rolls right, rather than giving indirect indications that can be understood in different ways.

      Still stucked thus....

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