I have a F 16 1/8 scale jet with JR 9711 servos in the elevators.

The elevators spontaniously twich??? I have seen this on the ground and in the air which is scary as it bobs dramatically 2 or 3 times then stops?????

I am using Spektrum AR 9100 power safe receiver with 2 Turnigy regulators feb by 2 x 2200 ma 2S lipos.

I am thinking that the long servo leads (over 3 feet) to the servos are causing RF that is feeding a strange signal to the servos to cause them to twich un commanded.

We all know that Spektrum does not glitch so what else can it be.

Would putting Ferrtie Rings half way down the servo leads solve the problem?? I have read that JR 9711 servos are suseptable to this sort of behavour any way???? I am also thinking of swapping them out for a Hitec or similar???

Any thoughts please???


Mav

do the servos twitch when you disconnect the servo?

http://www.rcuniverse.com/forum/m_95...tm.htm#9525254

Jason

This is not a jitter per your link. this is a huge twich moving the elevator surface by 40mm!!!!

Mav

I had to return a Hitec 7955TG that was doing something similar. They sent me a new one with a note saying the motor on the first one was bad.

Problem is both my elevator surfaces move at the same time that have JR 9711 on them???

Mav

Are both servos plugged into a seperate channel in the receiver, and not connected by some sort of amplified Y lead ?

I've seen this when in then "setup" mode on the TX. We you doing servo adjustments when this happened?

Just out of curiosity, what transmitter are you using ?

Had the "bumps" with a JR9303 with the TX the menu mode for an extended period of time as I was making adjustments.

My Kingcat did the same thing when I upgraded the 8411's to 8611's. They were on a Y harness, I got rid of the Y harness and all the problems went away. Ran them into a powerbox and all was fine.

I just had some 8711 do the same thing on ailerons. I pulled them out and put on some 8611's.
Scott

Yes plugged into separate channels on the AR 9100 Spektrum RX!!!

Mav

Using a JR 9XII tx. This is the same as your JR 9303 tx.

Not in menu mode when it happens either as happens in flight and on the ground.

I do note it happens when the turbine is running which happened on a ground run 2 days ago. Huge elevator deflection. Does not happen to any other model I have with this TX (11 models) so it can only be the JR 9711 servos??

Will ferrite rings in the leads fix the problem? Or should I just swap them out and give up on them????

Mav

Hey Mav,

Hows it going...

I have had some JR 8411 digital servos "twitch" when the output voltage from the regulator was set too high, at over 6 volts... Reducing the voltage to 5.8 volts made it go away... Maybe worth checking...

Ready for Cudel???

Rog

Are both servos twitching the same amount at the same time ? if they are, it can`t be the servos.

Ido apologise if i`m stating the obvious, as usuall these things are normally a prosses of elimination and if you throw enough ideas in the 'pot' something should come to light.

Yeah it`s the 9xII here in the UK, It`s our American friends that have the strange nbr`s on their transmitters (only kidding boys)

Does the 9 have the dual channel functions or did you mix them with a programable mix ?

Thanks guys for the ideas.

Yes both servos deflect the same amount. On the JR 9XII you assign a MATE to the elevator, which then gives you 2 elevator servos.

Roger good idea on voltage. I wll measure the voltage from the regulator and see if it is over 6 Volts. I am running it at the 6volt setting so maybe it is slightly over? Yes see you at Cudal.

As I have narrowed it down to the JR 9711's I will put ferrite rings on the leads and see what happens. Last resort will swap them out!