Prairie Predator Build

I've been working on a Nitro Predator for about a month and ahalf now. I'm stalled trying to figure out some problems with an Airtronics radio system I have that doesn't want to work. Everything "seems" OK but when I hook up servos to the receiver and try to control with the TX, no luck. the servos jitter when I apply power at the receiver, but no response at all to TX playing with adding a controllable rudder to the Predator for no other reason than the real one has one. So, I'm making it more difficult, I know. I'll probably end up fixing the rudder, but its fun to play with.
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  • Thanks Sgt Ric. I'm fairly confident in the interchangeability of various radio systems. Good to hear you've had good experience with that. I'll let you know how things work out once I know. I'm sure these are probably just newbie problems that had I gotten some aid from an experienced R/C'r I might have avoided. i don't want to blame the person I got the radio from, yet.

    I'm going to focus on getting the airframe and controls finished on the plane then move forward with the radio system.
  • Moderator
    Over the years I have collected quite a museum of old radios and flight packs which I have mixed and matched successfully for years.

    However, I am very cautious with the batteries and associated wiring.

    It has been shown that over time, the negative cable corrodes back from the battery outwards at a significant rate.
    While all the cells may still look good on the scope, the wiring is slowly degrading.

    I have disposed of all my nicad packs in favour of fresh Lithium and I try to baby them as much as I can.

    It just isn't worth it to chance a flight with so-so batteries.
  • Hey, thanks for the tips. ou know it could likely be either of those events. I've ordered a WFLY Rx for my Futaba radio, and its supposed to be compatible with Airtronics as well so...I'll keeping hacking at this Airtronics system. Its old but I like the feel of it.
  • Ron,
    I recently fried a rx when I plugged in a rx battery pack reverse polarity. All that happened was jittering servos after that.

    Another thing to check is the rx crystal. It may have been pulled from another rx (where it worked), but is not compatible with the present rx...
  • I had a radio system that had the exact same problem. It turned out that the RX crystal was bad. They are very sensative and if ever dropped (ie crashed) the crystal may fail. I would try swapping crystals and see if that fixes the problem.
  • Sorry, didn't get time last night to do pix of my Predator. Will try again tonight.
  • Moderator
    Here's Chris's post about "cramming" the nose of the Predator. (the balsa version, not the plastic/foam ones)
  • Yeah, I know. I didn't really think about that when I did it. My plan is to install the servo at the rear, just forward of the rudder itself. So, a short linkage and some longer wires and then see how the CG works out.

    I plan to install an autopilot, hoping most of it fits in the nose.
  • Moderator
    The NitroPlanes Predator is already pretty tight on space, requiring miniservos, so adding a rudder might take some squeezing.
    Don't know if you are adding any autopilot electronics, but it'll be a challenge.
  • JUst anote on the rudder.

    I found that the rudder part was all ready to be made operational.

    It was marked at thecut line and slitted for hinges already, so quite easy to do.
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