DS16/gyro401 problem

you still have not answered the question


has the heli ever flown before and the tail was not shaking ???

skyfreak wrote: you still have not answered the question


has the heli ever flown before and the tail was not shaking ???

It has not flown
You have to take it drop by drop or you will not know where the problem is
friendly heliven

exactly, drop by drop

so the heli has never flown before
now on the first flight it shakes with the tail
and the only point you are looking into at the moment is the jeti transmitter

in my humble opinion the wrong way
1st you have to start with the heli itself and check if everything is mechanically correct, that is the same as on rc-planes

and as a friend of mine had the exact same problem with the TREX 600 it seems very possible, that your problem has the same source ... check this image




the tube from servo to tail rotor (red) is very long
it is hung up and supported only by one hinge (green)
it is likely that when the tube (red) is too thin and moving back and forth, that it slightly bends (yellow arrows)

so when flying this tube is responsible for holding the tail steady
it makes many many small moves back an forth
if that tube is too thin and bends even just slightly, than there starts an oscillation and the tail is shaking

and this is exactly where my friend had the problem
so he went to an professional heli service and they changed the tube to a thicker one
than they hung up (green) not only on one point but on two points where the yellow arrows are
on top they changed the tail blades to larger ones

and voilá the heli was rock steady holding the tail and not shaking any more

next would be the gyro setting IMHO
as here you might have options to control how fast and sensible the gyro tries to send signals to the servos to hold the tail steady
and then as a last point the transmitter comes to game

you start searching in the transmitter only and insist on searching the problem in the transmitter
with a heli the transmitter IMHO has very influence
why? it send servos signals and thats all
all the rest is done by the gyro and therefor the possibility that the transmitter is the point of failure seems very little to me

rgds
guido

instead of searching bottom up for a solution IMHO you are seaching top down
ok lets try it this way

when a heli with gyro is hovering, what happens?

best case optimal conditions
the motor rpm and pitch are steady, the tail rpm and pitch are steady and the heli hovers
now we know that a heli is a quite unstable air vehicle, it tends always to fall out of this steady position
here is where the gyro comes into the game
the gyro detects the direction/movement of the heli and steers/correct "against" to hold it steady

so in optimal condition when hovering, you do not do any stick input and the signals sent to the tail transmiterwise do not change
now the heli maybe tends to turn his tail, this is where the gyro tries to steer against
so the servo for tail is pushing or pulling the red tube in the image above in order to change the pitch of the tail and therefor correct the unwanted movement to keep the tail steady

pulling is mechanically not a problem, but pushing
so when a push movement of the red tube is required to make a correction and if the red tube is not solid enough it might slightly bend which results in a not enough input to the tail and the gyro will push more
now the tail moves back into the right direction an the the gyro counter reacts to pull the red tube
pulling works easier as the tube cannot bent, but when pulling now the inpact may be faster and the tail goes to the other side
so the gyro pulls less and starts to push again
but push is reacting slower due to bending and the gyro pushes more again to hold the tail in position
and now it starts from top
back forth back forth in minimal movements where pull is always haveing more inpact then push (due to bending)
and voilá the gyro has to make loads of corrections wich leads in to an oscillation that becomes worse and worse

in all this scenario the sticks on transmitter have not been moved at all
so the input on the servos comes from the gyro and not the transmitter so to say

does that make sense?
and if it does, why search for a solution in the transmitter and not the heli mechanics and/or the gyro settings?

I might be wrong here as I do not fly helis
that is only the experience my friend made with the trex 600 and how he solved this I already described

so I am sorry, maybe some other with indepth heli experience may jump in and if I am wrong please correct me
I am by no means knowing everything but am always willing to learn

rgds
guido

Hello
the GY401 needs +50 and -50 on the yellow cable that is +50 heading hold -50 normal gyro.
And you should be flying in heading hold If the tail is still shaking +50 too much then go to +45 and try again.

tomsl1 wrote: Hello
the GY401 needs +50 and -50 on the yellow cable that is +50 heading hold -50 normal gyro.
And you should be flying in heading hold If the tail is still shaking +50 too much then go to +45 and try again.

Thank you for your contribution
Should I trim in servo setup gain?
Should I then set the same values in Gyro Settings?
Thanks in advance