ok, here is the situation.
crappy 50 with an OS46, 550T with 8700G. boom mounted servo (with one servo extension), carbon push rod, engine runs smooth, no vibration in hover, new glow plug.
after flying for two or three minutes the tail servo starts twitching, the longer flying the more it twitches. does it as well with gyro gain to 0%, HH and non HH. no twitching with engine off or idle. does twitch at low RPM the same than at high RPM. does twitch in FF the same than in hover. tail belt is tight and not slipping.
did fly with the exact same setup for a couple of tanks and no problems, this started all of the sudden. NONE of the of servos a twitching. frequency check comes out CLEAR.

any ideas where i could start looking... at this point it could be almost anything... any input?

thanks

Sounds to me like the servo is trying to tell you it is about to quit working. Seen those same symptons before, right before the servo quit working


David

mmmh... servo is brand new (about three hours of flight time) and never had a JR servo quit on me (but there gotta be a first). also would i have not some twitching even with engine off...? i might try a different servo...
thanks... more input coming please ...

I got a buddy that tried the same thing. Tail mounted servo, and the sme gyro/servo combo, and it did the same thing. He switched it back to the stock location and everything works fine now. Try moving it to the origional location. Seriously, it was exactly the same thing.

ergo60, had the same thought, might try that, if i can find the orginal hardware...

Yeah, I called my buddy to verify the details, and it is exactly like you said, he had to but new stuff.

I had this problem on my Kalt Baron 30S ...Drove me up the wall...changed servo, reciever...still had the twitch...moved to origional location..still had twich...changed the gyro...aha problem solved...BAD GYRO....

what gyro was it helo36?

Hmnmm...good question.....I think it was a Peizo...the older kind...no heading hold. Not sure I think I threw it away

Are you running a 4.8 or 6volt bat pak? I'm waiting to hear confirmation on this but, my theory.
your running a 6volt pak with a regulator your regulator is telling you it's about to pak it in causing your servo to twitch the longer the servo is receiving power friom the Gyro the worse it gets because now the Gyro starts to act up.
________________________________________
Remember this is a guess!!!!!!! Be interesting to know if you are running a 6volt pak

" about to pak it in causing" what do you mean with that ?

running 6v on 5.1 regulator, 1650mh

tried today a "glitch trap" instead of the extension and the glitching went "almost" away... to an acceptable point, 1 or two in a full tanks flight...

" about to pak it in causing" what do you mean with that ? "
_____________________________________
If your regulator is failing and your Gyro and Digital Servo are receiving anything over say 5.5v the voltage increase will cause the digital servo to twitch. If the Regulator is not working at all your Gyro will heat up causing a worse condition after a few minutes of operation. I would install a 4.8v battery pak and see if that fixes your problem!!!

i think he meant "casing"

If changing the servo extension to one with a filter in it lessen the glitches. I would look at routing the servo lead a different way or moving the servo back to front, so there will not be an extension in the system. FM is very particular about long servo leads and where they are placed.

David

I think he means the pack is about to pack it in as in DIE, CAUSING the servo to twitch. I can't spell either.

Causing as in Because. <sp?>

Sounds like the belt is causing static electricity, had this problem on tail mounted servos on shuttles. Put a ground wire on servo to motor mount and it was gone........ just a guess.....

bob, i had that thought as well, but how would i go about it? (where ground the wire at the servo?)

pack has plenty of power and voltage and it is a pcm receiver, can't run without extension from the tail... and now that i remember i had some twitching (bit less) at the original servo location)

i think bob is right on, hope he gives me details on how to fix it...

thanks

Run a wire from the tail boom to a negative pole on the RX. That way the static charge will not be noticed by the RX.

David

I had the same problem on my Raptor. I could not figure it out and sold it for parts to a Raptor driver. He rebuilt it and found a problem with the tail pulley. He put the screw in properly and the twitch went away. I tried the grounding wire and it didn't help mine. Good luck.

i wish i could find somebody to buy my Craptor...

How much you want for it? I LOVE mine!!!

you wanna buy with electronics and engine (os 46) ?

Give me some options and I'll think about it. Having two helis around isn't a bad idea.

Just run the dang ground and tell us if it's fixed
____________________________________

NO NO NO NO NO!!!! I wanna 'nother rappy!!!

LOL