Hi. Thanbks for all the input.
Are you sure it's not something wrong with the gyro? Unplug the servo from the gyro and plug it directly into the receiver and see what it does.
At first, I thought it was the gyro too, but i tested it with another servo, and it worked fine.
i would suggest a stronger servo on the tail. and a metal geared one (not sure how strong the nes-810g servo is. i usualy only deal with minis)
but servos especialy the tail, get a lot of stress and eventualy they have to give.
I think you are right. I will look for a better or stronger one!!! Do you have anyone to suggest ?? perhaps a 9650???
Thanks again
Manuel Menzella