Hi. I have the Align RCE-500 gyro with heading hold. Nine times out of ten, when I apply power to the system, the gyro will move the tail pitch servo arm completely forward (which would move the head of the TRex to the right). The "set" light stays continuous blue. When the servo "rails" this way, I have no rudder control at all. After resetting the power many times, it will eventually center the servo and performs as expected. I have a digital HDS-877 servo that behaves the same way. What could be the cause of this problem?

My setup:
TRex 450X CDE
JR XP6102 TX, no revo mix
JR R700 RX
Hitec H65-HB servos
11.1 LiPo

RCE-500 gyro, mounted vertically on the side of the boom housing (sticker facing out). Gyro signal is plugged into CH4 (Rudder), gain is plugged into CH5 (Gear)

Two observations:
(1) When laying by itself on the table (sticker facing up, which should be incorrect), the gyro initializes fine.
(2) When installed on the TRex, it tends to work well when I apply power with the TRex sitting on the hood of my car (weird!?). I know piezo gyros work from stress of inertia, and not magnetic fields. Maybe my car hood has the right tilt?

I eventually plan on getting a Futaba HH gyro, but I'm still absorbing the initial outlay for the TRex and required equipment (ie, sack lunches at work for a while . In the meantime, could anyone shed some light on what is going wrong?

Thanks,

Billy

maybe is because of the servo......I don´t know if that gyro "support" a digital servo......

Thanks, I will try out some of my other servos that are not digital. Strange how it works intermittently, though.

Dustorm. I can tell you it is not related to digital servos. I am all digital and using the same radio, receiver and gyro. Try this and let me know the result. Unplug the gain on channel 5 and adjust your gain manually on the gyro. Start at 50% (with the slot on the gain screw at 12:00 on the gyro). I am just curious if this resolves your issue. I never could get this gyro to work correctly with the gain wire plugged into channel 5 on the R770.

lcbabj, unplugging the gain channel seems to help. I think I will try hooking the gain channel to the throttle so that I can see what effects different gain settings have on initialization.

Thanks!