Help! Video added Elevon set up on FT MM F22 chattering

[luvmy40]

Hi all! Another Newbie here with, likely a stupid question.

I have the Fly Sky FS-i6X radio and several iA6B and an iA10b receivers. I have 2, 4 channel models set up(Simple Cub and MM Corsair) that work perfectly.

I have a Elevon model set up for a Delta Wing that I just picked up last night at the FT Fun Fly at KSU and it works perfectly.

I am just finishing up the FT MM F-22 Raptor and I copied the elevon model from the delta wing for it.

The functionality, i.e., left/right/up/down is all good, but the elevon servos chatter like mad! The control surfaces move smoothly. There is no drag on the push rods. I can't find anything that would be fighting the servos, but they just start oscillating like crazy and don't stop until you grab the elevons and stop them. I tried 2 different receivers and two different ESCs. I even tried running off a 4 cell AA pack with the motor out of the loop. The same oscillation happened. When I remove the push rods from the servo control arms, they behave as the should. When either push rod is reinstalled, that servo starts the dance show. To clarify, the oscillation is not full deflection, just 5 degrees or so, but very rapid.

I did sync it with both elevon models on the radio and it does the same thing, while both models work fine on the delta wing.

I am at a complete loss here. Any input would be greatly appreciated.

Thanks!

 

[luvmy40]

Here's some video of the oscillation.

Again, if I disconnect the push rod from the elevon or the control arm, this goes away. When disconnected from the elevon, I cannot manually cause the oscillation with any manipulation of the push rod. If only one side is connected only that servo oscillates. It appears to me that this a physical feed back from the control surface rather than programming or electrical/wiring issue.

 

[DaneB]

Hi all! Another Newbie here with, likely a stupid question.

I have the Fly Sky FS-i6X radio and several iA6B and an iA10b receivers. I have 2, 4 channel models set up(Simple Cub and MM Corsair) that work perfectly.

I have a Elevon model set up for a Delta Wing that I just picked up last night at the FT Fun Fly at KSU and it works perfectly.

I am just finishing up the FT MM F-22 Raptor and I copied the elevon model from the delta wing for it.

The functionality, i.e., left/right/up/down is all good, but the elevon servos chatter like mad! The control surfaces move smoothly. There is no drag on the push rods. I can't find anything that would be fighting the servos, but they just start oscillating like crazy and don't stop until you grab the elevons and stop them. I tried 2 different receivers and two different ESCs. I even tried running off a 4 cell AA pack with the motor out of the loop. The same oscillation happened. When I remove the push rods from the servo control arms, they behave as the should. When either push rod is reinstalled, that servo starts the dance show. To clarify, the oscillation is not full deflection, just 5 degrees or so, but very rapid.

I did sync it with both elevon models on the radio and it does the same thing, while both models work fine on the delta wing.

I am at a complete loss here. Any input would be greatly appreciated.

Thanks!

Whatever else happens, just know that you are loved. Heh.

Here's some video of the oscillation.

Again, if I disconnect the push rod from the elevon or the control arm, this goes away. When disconnected from the elevon, I cannot manually cause the oscillation with any manipulation of the push rod. If only one side is connected only that servo oscillates. It appears to me that this a physical feed back from the control surface rather than programming or electrical/wiring issue.

It would IMHO, seem as tho the servos are fighting each other. perhaps a ground issue where they are both just that poorly grounded so as to feed back unrequited usage of voltage input which is tantamount to an automobile with a burnt out turn signal bulb which makes the second bulb on that side (front or rear) blink at double speed. Just a thought dearies.

 

[flyranger]

I just maidened my FT F22. I had to move the servos to the tail and hinged differently. Flew well.

 

[Merv]

...I am at a complete loss here. Any input would be greatly appreciated...

That is weird.
I agree with @flyranger, try moving the servos aft, that is, shorten those pushrods.

Im guessing it a pushrod issue. The alternative, better support for those pushrods or thicker pushrods.