RunRyder - Spectra g tail servo noise

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Gasser Model RC Helicopters > Spectra g tail servo noise

Trevor G
Heliman
Location: Brisbane, Australia

Hi Guys,
Can anyone offer some advice on a noisy tail servo in a spectra G?
I have a 9252 running through a GY401 on it and I`m still on the first gallon of fuel with a hanson 26. The servo has just started making a horrible graunching sound when it is finding its new position. The gears aren`t stripped.
I pulled the servo apart and it`s the motor making the noise but I think it`s the driving circuit causing it as the motor runs fine. The 401 is in non digital mode and gain is way down for the run in of the engine.
The noise is actually the motor itself when it`s operating, much like how an align speed controller uses the motor as a speaker to emit tones when you`re programming it, but this tone is awful. I plugged the servo into the receiver direct and it still does it. Sounds fine while it is actually moving, just as it stops and starts.
Is this servo dying a premature death? Would prefer to replace it then wish I had!

06-29-2008 10:37 AM

Brunobl
Veteran
Location: Pomerode, SC, Brazil - 26 40S 49 11W

In my opinion the servo is talking to you. Listen to what it is saying.

If it were my Spectra I would just replace the servo and be over with it. You will never forgive yourself if the servo finally fails on you after giving audible sign that something is not right.

I use 9252 servos in my swashplate and none of them make odd noises.

Quote
Sounds fine while it is actually moving, just as it stops and starts.

The tail servo starts and stops, reverts direction, etc, all the time. If is making strange noises at all and particularly when starting & stopping, I'd definitely replace it.

On a side note, why are you using the gyro on non-digital mode (the 9252 is digital)? And, why are you using a 9252 on the tail? It is rather slow for that IMO at .14sec. I am using a 9254 that is more than twice as fast at .06sec, although admittedly it has lower torque than the 9252. I've never had a glitch with the GY401/9254 combo in my Spectra.

-------------------
Best regards,
Bruno.

06-29-2008 12:19 PM

Trevor G
Heliman
Location: Brisbane, Australia

I did have 9254 on my last spectra but it didn`t survive the abuse of running in an engine either. I have 9255`s on cyclic and they are fine.
The engine has taken 6 tanks of fuel to screw this servo.

The tail servo starts and stops, reverts direction, etc, all the time.
Yep...like every time the zenoah fires!!!!!!!!

I`m trying to think of a way to finish running in and tuning this engine without breaking anymore expensive servos.
What gyro mounting tapes are others using on gassers out there...I think that may be a big part of it.

I am (was) using the 9252 because it works for others with spectras and it is more torquey for the gasser.

06-29-2008 12:26 PM

Brunobl
Veteran
Location: Pomerode, SC, Brazil - 26 40S 49 11W

In my Raptor days (long gone now) I used that 3M double sided cushioned tape to mount the gyro. It worked alright, but needed to be replaced often. With hindsight I now think the real problem was the excess oil in those helis, everything eventually got soaked in oil and the tape was no exception. In my Spectra I am using the original double sided foam that came with the 401 with good results. At first I wrapped the gyro with Velcro as a safety measure to secure it to the frame, but I have now dropped this with no problems.

Well, if the 9252 works for you in the tail rotor, specially during engine run-in, when there is more kicking around, then by all means do use it. It has more torque for sure than the 9254.

But I still suggest replacing it even if for another 9252 because of the strange noise. Something might not be right with that servo, it isn't worth risking the Spectra with it.

Good luck and have fun with the Spectra, it's a wonderful helicopter!

-------------------
Best regards,
Bruno.

06-29-2008 01:10 PM

xcellgasman101
Elite Veteran
Location: WOODWARD, OKLA....

I agree with Brunobl about changing it out,, But I do have some questions,, How come your still tuning the engine after almost a gallon of fuel thru it?? that should have been done on the first couple of tanks!!! There is no gain running the engine rich for that length of time,, You want to get that engine tuned asap, so your not shaking the heil to death,, I use the green Zeal gel tape for mounting the 401 on my gassers, it thick and very shock absorbing and can be cleaned up with soap and water, to make it sticky again,, Hope this helps.. XGM/VGM

John Crotts
www.soonerhelicamproductions.com

06-29-2008 01:23 PM

HOMEPAGE

rbort
Elite Veteran
Location: Franklin, MA - U.S.A.

Not to send you the wrong way

But I found the 611 gyro works much better than a 401 in my Spectra. Besides the fact that it holds a constant pirouette rate when you fly around, I think the 611 sensor is better suited for more vibrations and my tail was alot more solid with it than with a 401. Granted I had the 401 when it was first new with a new motor, but I replaced it quickly with a 611 and found it held the tail alot better all around.

The 9256 servo that comes with the 611 seems to last quite a long time.

-=>Raja.

1005 Xcell Gas, BHH G26 3D Plus, Jewel Generator
Spectra-g, BHH G26 3D Plus, Jewel Generator

06-29-2008 05:28 PM

Trevor G
Heliman
Location: Brisbane, Australia

Thanks everyone for the responses.
I was using a 9252 on tail because I didn`t think a 9254 had enough torque for a gasser tail. I didn`t use digital on the 401 because I didn`t know the 9252 could take the 270HZ signal, so I played it safe.
I`m fairly new to this gasser bit and I read that I should lean it up slowly over the first few gallons. I have to agree about sweetening it up so it doesn`t shake the heli to death. Maybe you all wouldn`t mind giving a few pointers.
I`m running 32:1 mix and I have the needles at 1 3/8 high and 1 1/2 low.
It idles roughly as you would imagine. I leaned the low end towards 1 3/8 until it spooled up smoothly and the high needle took over, but after a refuel and cooldown it wouldn`t restart. It would fire and die over and over, but if I wound the low back out to 1 1/2 it started again fine. Also the idle hunts at this leaner low end setting. Plug looks good.
I have full throttle trim to idle it at 1 1/2 low.
The motor is a Hanson 26 with stock muffler and airfilter for now. Gear ratio is 7.15:1.
Can anyone suggest where to head from here????
I`d love to know roughly how much throttle trim it should take above full closed to idle the gasser, as that would tell me a lot, and also some other pilots needle settings, especially the low end.
As advised here, I am chasing the zeal tape down now.

06-30-2008 09:15 AM

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Gasser Model RC Helicopters > Spectra g tail servo noise

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