vexing Radian control issue with Graupner GR-12 and MX-20 (MC-20).

Discussion in 'Radian' started by Bryan Harvey, Feb 24, 2013.

  1. Bryan Harvey

    Bryan Harvey Member

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    In single pilot mode I get inconsistent control of tilt, or none at all in stabilized slew mode with my Graupner setup.
    I am running Spektrum satellite receiver for dual operator mode and have no control issues when flying two-person.

    As you can see in photo 1 below in the Diagnostics window, the top slew indicator shows 122% but the slew in the lower left shows 0%. This is what I get when I am not able to control tilt at all.

    slew 1.JPG

    To remedy the situation, I switch out of and back into stabilized slew mode to try and regain control, with varying results. In this photo#2 you can see the top slew indicator says -78% and the bottom one says -198%. In this situation the tilt control works in that direction, but shouldn't they be indicating the same thing?

    slew2.JPG
    Also these values change at full deflection if I switch stabilized slew off and then back on, and they are never symmetrical at full deflection one way versus the other. I'm using a paddle switch on the side of my MC-20 to control the tilt. It almost seems like the center point of the control input is drifting around arbitrarily.

    Any ideas here on what could be happening?
     
  2. Gary Haynes

    Gary Haynes Administrator
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    Bryan the photo attachments didn't work. Here's the trick for photos. Click the Upload file button in the bottom right. Add your photos. Once added place the cursor where you want to insert them and the on the photo click on Full Image. No need to attach them using the picture icons.

    If it shows the attachment as a hyperlink text it won't work.
     
  3. Bryan Harvey

    Bryan Harvey Member

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    hey Gary, that's how I originally uploaded, but I edited and reposted again, and it seems to be OK now.
     
  4. Gary Haynes

    Gary Haynes Administrator
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    Bryan not sure how you are doing the test but here's what I found.

    I have my Min angle set to -56 and Max to 20. If I do a tilt up I get to the tilt Max. If I run the tilt control full up I see in the Diagnostics Window that the Slew is 98% and the Slew % is 95%. Like wise if I do full down I see -102% and -95%. My zero point on the control is -2%/0%.

    I believe that the Slew % is just a readout of the amount of deflection in your tilt control You can see this by putting the Mode control in Mode 1 (stablized) and moving the tilt control.

    If you think that the readings are two far apart I can think of a couple of items that would do that. Either the channel isn't reading 0 when in the middle or a curve has been applied to the channel.

    Maybe Andy, Brad or others will have further suggestions.
     
  5. Bryan Harvey

    Bryan Harvey Member

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    Thanks Gary. Actually I've just discovered that if I have my paddle switch centered when I cycle the gimbal mode, then I have proper control of tilt in both directions. If it's deflected one way or the other when I enter stabilized slew mode, then I have a problem. So for some reason I guess the zero point is reading whereever the paddle control is at the time of entering slew mode. Not ideal, but certainly something I can work with for the time being.
     
  6. Gary Haynes

    Gary Haynes Administrator
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    Bryan just tried it and you are correct.

    If I start with my slider control below zero, say 25%, switch from Mode 0, to Mode 1 and then Mode 2, the Radian thinks that the current position is the zero point. Only real way i could find to sort it out was to go to Mode 2 so that the Gimbal stablizes at the Gimbal zero point, switch to Mode 0, reposition the slider to the correct zero point and then go back into the stabilization modes 1 and then 2.

    Worst case was having the slider close to the full tilt down spot and having no down at all, only up. Reverse is also true.

    Bottom line, if you are using a rotary or slider you need to be at your zero point when you start.
     
  7. Bryan Harvey

    Bryan Harvey Member

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    Thanks for confirming Gary. I was scratching my head for days about this, thinking it was some interference issue between my Graupner receivers, but good to finally have it figured out.
     

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