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Old 11-03-2005, 11:02 PM
Bob Pastorello
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Default Tail Servo Fluttering!!!!

I want to check my thinking. GP Ultimate, in the shop, setup is 8611 on rudder, 2 - 8231's on elevators, all in the tail. Power up, everything is ok, until I turn on the tx. JR 10X, BTW. As soon as it's on, elevators and rudder start bouncing big time, like a fast flutter. Putting slight load against the surfaces does not stop them, but SLOWLY moving elevator through neutral DOES stop the weirdness.

Three rx's tried, two separate channels, one FM, two PCM.... wing and throttle servos do NOT do this. I have 24" extensions, JR H-D on the stock servo lead, plugged direct to the rx.

What is up, here? ANY suggestions? (have tried all the rx and battery, switch harness trade outs already)

Yep. Here's what I have changed/tried as of this morning - with NO success;

1. Changed FM Rx to PCM Rx
2. Changed different RX to different freq AND different modulation
3. Changed TX modules
4. Changed TX's (tried my 783, in both PCM and FM mod)
5. Plugged elev/rudder servos into OTHER channels on RX to eliminate encoder possible problem (tried this on multiple receivers)
6. Split servo wire and servo extension on elevator servo, twisted in drill, ca'd to hold twist.
7. Changed battery
8. Changed switch

Since there are THREE servos doing this flutter thing, although to varying degrees, I long ago determined a servo is not the problem.

Tonight I plan to try Hitec Servos in place of the JR 8321's (but I don't want that to be the solution). Yes, this does the flutter thing OUTSIDE!!!! It is AMAZING to see this; I've run JR for decades in LOTS of configurations and I have NEVER seen anything remotely like this.

Changing servos DID NOT fix this issue.

ANYONE with any ideas whatsoever????