Servo Matching arc

  • Hello!

    I am matching a 2 servo wing for the first time with the Mercury and followed the instructions as per the manual and videos available on Youtube from Pickering.

    Setup from my Tx:

    CH1 from my 18MZ going to AIL1 (right)

    CH6 from my 18MZ going to AIL2 (left)

    From the PB I have mapped:

    input CH1 to AILERON A (right)

    input CH6 to AILERON B (left)

    Output mapping from PB:

    Output A to Function AILERON A (master inboard servo)

    Output B to Function AILERON A (slave to match)

    Output M to Function AILERON B (master inboard servo)

    Output N to Function AILERON B (slave to match)

    When proceeding with the matching function for the left wing (AILERON B going to M and N), I have setup the inboard servo first through the TX, end points and mechanical linkage correct. The wing moves perfect with this servo on its own, perfect deflection both ways. Then I choose to match Output N (slave) which I guess the PB matches to M and consequently the same will be when I do the right wing (choosing B to match as slave to A).

    I followed the instructions initialising the channel first.

    1st question: When initialising in this case output N, I take this process analyses the travel end points and center for channel M which is the one that N will slave to?

    Once I have done center and end points, I then connect the linkage of the second servo N which I have matched. Linkage fits perfectly on center and endpoints BUT when I then test both servos together throughout the whole travel, 2nd question: Does the PB not only matches center and end points, but also the entire arc or travel in between these 3 points of measurement?

    The reason why I am asking is that once the servo connected to N is perfectly matched to M as per the instructions, I find that at center and endpoints none of them scream and they are just fine but when I do stop the stick half way through the arc, servos start fighting at certain points!.

    I have tried tweaking the end points and center through the matching process several times and I can get no screaming at these points but at some points half way through, they still scream.

    Note: linkages and geometry on both servos are almost perfect (can't never get 100% optimal geometry). PB version 10. Futaba 18MZ, SB7008rx

    pictures below

    Thanks for your time PB team! 8)

  • Hi Richard

    Don’t really understand, are you saying that if this happens is because of the linkages not setup properly?

    I would have thought the powerbox servo matching function would match across the entire travel arc instead of end points and center only. What is the point or advantages doing this through the powerbox if I can do this via the transmitter assigning all servos to different channels and adjusting the travels etc.. through the radio?

    I thought things like match boxes used in the past would do as the powerbox servo match function.

  • Hello,

    no I didn´t say that - also servos may have some slight offset, but from my experience it is not more than some tens of a millimeter.

    Doing it in the Powerbox has the advantage that you set it once - it cannot quickly be unmatched due a mistake in the radio. It is newer possible to match the whole range - only a certain number of points 3,5,7.... but makes it very complicate. 3 points worked fine the last 15 years!

    Yes- matchboxes also have only 3 points adjustment!

  • Hi Richard

    Thanks, after many many hours, I managed to get all servos in perfect SYNC across the whole arc!, I had to fine tweak some of the linkages and now is perfect!,

    Sorry for the questions, it was my first time using a PB for servo matching and I wasn't sure 100%