bob8619

Hey my right aileron yesterday starting twitching and was mainly stuck in the downward position, luckily it was after I was done flying... It only stopped after turning both the receiver and transmitter off. Its a Spektrum Dx7s. First time using 2.4 so not sure if thats avoidable or if I have some other issue going on.

flyinwalenda

My Feedback: (5)

Twitching on just one servo could be a bad connection between the servo and the receiver, it could be the "pot" inside the receiver is dirty or damaged, if the aileron took a hit while lading the servo could be damaged. It could also be too long of an extension bewteen the receiver and servo and a quick fix for this is to tie several knots in the extension.
If it never did it before then it's probably something above.
If several servos do it then it could be too much voltage from the battery pack.

bob8619

Thank you sir.

Rodney

If you have an extension on that servo, it is most likely a bad connection. Just unplug and replug the connectors again to improve the connection as the plugging/unplugging tends to scrub any dirt or contaminates that may be on the pins. That is why I NEVER use an extension where it will not be occasionally exercised.

Gray Beard

My Feedback: (-1)

I ran into this problem when I used extensions and saw a lot of crashes at IMAA events when the long extensions were corroded. I was guilty of not cleaning the extension leads in my big planes too so I started soldering the wire needed. Just lazy on my part but I no longer have this type of problem.

Jetdesign

My Feedback: (8)

I don't think it's anything related to 2.4 specifically, the technology is not prone to that kind of issue. I've had this happen once or twice and for me it was the servo pot. The pot is an electrical potentiometer (variable resistor) that the servo uses for positioning. As other's have indicated it would be an issue with an extension or some wiring issue.

1) try swapping right and left channels at the Rx. If you are using extensions, plug the glitching servo's extension into the opposite aileron and see if you still have the issue - would indicate if the issue is within the servo or wiring
2) try disconnecting the servo horn and see if you still have the issue - would help diagnose if the servo pot is worn (sometimes when pot is just starting to wear you get this response only when a load is on the servo. if the glitching stops it would be a good indicator it's the pot).
3) plug a different servo into whatever the glitching servo is plugged into. if it works you know it's the servo.

SeaJay

My Feedback: (6)

Just a curious question on my part.. If the servo is twitching because the servo extension is too long, how would tying several knots in it help? tying the extension in knots would shorten the overall length of the extension, however, the overall wire length would remain the same! is the extension acting like an antenna, and shortening the servo lead (by tying it in knots) would make it receive less interference signals?

Thanks, Craig

Rodney

Tying knots wont help a bit but it won't hurt anything either. It would be very dificult to put a long enough extension in to upset the servo unless it was a very small gage wire where the IR drop along the wire would be significant. Unless you are using much less than 22 gage wire, you would need many feet of wire to make a noticable effect. Now, a bad conection such as a corroded or dirty one can cause a problem regardless of how short or long the extension is.

SeaJay

My Feedback: (6)

Rodney,

Thanks for the info, I just wasn't sure that if by putting a couple of knots in the servo lead, you were in essence putting a pseudo RF choke in the line, thus reducing RF interference!!

Thanks for the clarification!!

P.S. I also like the longer servo leads to be soldered, to eliminate any chance that there would be a problem with a hidden servo connection!!

Craig.

Jetdesign

My Feedback: (8)

I have extensions that run the length of my 72"-78" planes (well from receiver to elevators, 36" to 42" extensions) and have never had an issue due to extension length.

K-Bob

My Feedback: (1)

Whew! I thought someone was playing a practical joke. I told my wife that the reason her laptop was locking up was that she had knots in the AC adapter cord and it wasn't letting enough power through.

Jetdesign

My Feedback: (8)

Before anyone starts fooling themselves and wasting time tying things in knots, please Google "Ferrite Bead".