Tricopter servo interfering with ppm signal

[Willian_II]

Hello, folks.
I have been using multiwii for some time now.
It was working perfectly on a quadcopter, but now i'm trying to build a tricopter, and i'm having weird issues...
when the servo is under heavy load, the ppm signals on the receiver gets all messed up! they just start jumping around.
as soon as i disconnect the servo, it stops.

this is my current wiring(ms paint):

the escs black wires are not connected together(the signal ones), but it worked on the quad setup

i tried some things, like connecting the servo directly to receiver, problem persisted.
also tried to power the multiwii from the usb, and disconnect the 2 front escs(had to connect servo ground to multiwii ground) and still didnt work =[
also tried to connect another servo directly to receiver, same thing happened.
also tried to connect servo and multiwii grounds.

rx is a HK tr6a v2 ,
tx is a t9x on er9x
escs are HK SS 15-18A
servo is a Corona 929MG Metal Gear.
multiwii is an arduino Uno with gy-80 chinese IMU.

i ran out of ideas... can someone help?

thanks!

[noobee]

I have a similar problem (channels jittering) with that servo as well. My Rx is the frsky 4ch that is set up in cppm mode. Added a choke and I think the situation improved somewhat but still not good.

Changed the servo to a different type and it is well after that.

[PatrikE]

Corona 929MG MG is using a lot of currant.
Connect the sevo to a Ampere meter an you will be suprised!...

Iw'e seen the same on a gimbal i made.
The esc probably can't deliver enough power to drive the servo.

[Hamburger]

interesting.
I have those servos in my MultiWii heli and run them from the ESC's BEC. Then that current from 4 servos might well explain why I see occasional cyclic drops with fast recovery.

[Willian_II]

But how does that happen?
I mean, the servo is powered alone by an esc's bec.
Can the interference travel through the battery wires?
Is it possible that my aluminum frame has something to do with it?

In a few hours i'll test with a different servo, and see if it gets better,
probably make a video too, for the record.

[Willian_II]

Here is the video, everything works fine with the servo standing still, but when it moves, everything goes crazy!
http://www.youtube.com/watch?v=kbuDPTnr1gw&feature=plcp

[Willian_II]

tried a different type of servo, it works now