First, Here's my setup:
New Align T-rex built from kit;
Walkera 3200Kv brushless with 12t pinion;
E-flite 20A ESC;
2S3P 2600mah lipo;
TowerPro 9g servos on Ail, Elev, Pitch;
Esky 6g servo on Rudder;
Align HH Gyro.

The gyro is mounted vertically on the left side of the tail boom mount. The tail pitch motion is smooth (with the servo plugged into the Rx aileron, the motion is smooth, crisp and at the full speed of the servo). Gyro wiring is down the left frame to the rear mounted receiver. Front servo wiring is along the bottom of the right frame. A Deans whip antenna is mounted beneath the right front skid brace, pointed rearward

I am using the on board gain adjustment on the gyro. The lower 1/4 of the pot gives rate, the upper 3/4 gives heading hold.

The problem:
With no motor (throttle hold), and the gyro in HH mode - the tail servo moves to one extreme as it should. But, in rate mode, the servo motion is very slow and delayed has it attempts to follow the rudder stick.

With the motor, the gyro in HH mode, and the heli getting light on the skids - the heli yaws in one direction and is very delayed in responding to opposite stick. When it does respond, it goes full tilt in the opposite direction, even though the rudder stick is released at the direction change. In rate mode, the rudder seems to respond correctly, but very sluggishly.


Any thoughts? ? ?

Thanks!

I'm not really qualified to answer this as I'm just a novice pilot, but maybe positioning the gyro horizontally might fix it.

It would seem that if the gyro is initialized vertically, that it would respond better to a different direction of movement (one of your cyclic pair of directions). I would try mounting it flat horizontal and see if that helps.

I guess the new gyro should be mounted the same way as the old and that is vertically with the sticker to either side.
It's easy to know if it's right or not, if you mount it lying down the heli will spin out of control upon trying to lift.

Are you sure you don't have any mixes working on your radio?
Duals set at low value?
Expo set at low value?
Any delay settings on the gyro?

deli_conker,
Norrmannen is correct. This gyro, contrary to the instructions, mounts vertically. It mounts with the sticker vertical, pointing in any direction. But, thanks for the try.

Norrmannen,
My old Futaba T6XH doesn't have dual rate for the rudder, though I am running duals on the aileron and elevator. It doesn't have expo either. And, to the best of my knowledge, the gyro doesn't have any delay function. Again, thanks for the try.

I'm at a loss here. I've followed the setup instruction given on "trextuning.com" to the letter. As it stands, I would be better off without a gyro. At least I would have some control over the tail rotor!

I started up with the old Align gyro and could never get it to work properly so I put it in a drawer and bought a Futuba 401. Have bought another for the XL I've just finished.
I would have tested another servo if I were you Esky servos aren't really "top of the line" stuff. (Just try one of the others on throttle hold)

In HH the servo might creep but with a proper mechanical setup, that is with almost no drift in rate without using trim, this creep should be very slow.
Mu Futuba doesn't act that way even with a low gain setting but adjusting up your gain to almost max to test if you get a crisp response (but tailwag) would be my next step.

Try putting the gyro and tail servo on another channel to see if behaviour alters, in case the problem is your radio.

Norrmannen,

Some good thoughts - I'll give them a try.

Being stuck with the servos on hand (spent current budget on the heli, gyro, motor & ESC), I choose the Esky because a) it doesn't have any play in the servo arm (the TowerPro's do), and b) the Esky's lead wire is in a tight twist (hopefully less likely to pick up noise).

Right now I'm fighting glitches. The TowerPro servo's leads had been lengthened for another use and are doubled up and tie-wrapped. I just received some servo connectors, and will shorten the leads to exact length required. I've relieved an old PC motherboard of two ferrite rings and will put one on the gyro - to - receiver lead, the other on the ESC - to - receiver lead. I'll perform your suggested 'different servo' and 'different channel' test when I do the anti-glitch work.

A thought on anti-glitch: Replace the servo leads with 2 conductor shielded twisted pair cable. Use the shield for DC Common (the receiver will tie all of the shields together). It seems that this should offer some protection to the servo's signal wire.

Thanks for the suggestions!
pt