Tail wagging question....

[Deano]

I have the Stinger 90 that I bought over the winter and I am just now getting it off the ground. My problem is I can not get the tail to settle down. It wags all the time. My linkage is fine, I have even taken my gain down to 32% and it does the same thing. I then tried moving the rod on the servo arm in closer and still, the same thing. The tail blades look fine. The gyro is a GY401 with on digital with a 9254 to run tail. I had heard that you really don't want the gain below 60%. What else could I try? I really don't see any vibrations. :arggg: :arggg: :arggg:

[WJackson]

What radio are you using?
oh, is engine broke in running normal?

[Deano]

radio is a Futaba 7chp and engine is a 90 c-spec already broke in. After looking over it this evening I noticed that on the vertical fin in the back, the lower bolt that goes thru was almost completely off. I fixed it but have not flown since. Can that cause the problem I have been having??

[flyinfool]

Anything lose can and will cause problems.
I would be surprised if a loose fin is causing a tail wag, but it is possible.
My first thought is an engine with the needles not quite right yet. Either rich or lean can cause a tail wag.
How and where is the gyro mounted? To hard of a mounting or to close to the engine has been known to cause wag also.

[Deano]

Gyro is mounted just behind the main shaft. I will double check the needle settings but I'm pretty sure that I set them when I got the engine.

[flyinfool]

I will double check the needle settings but I'm pretty sure that I set them when I got the engine.

What are you setting the needles to?

[Deano]

mid is 1 turn out and high is 2 turns out.

[flyinfool]

That is a good starting point but the needles must be tuned to your specific setup.
Depending on many variables such as, type and brand of fuel, muffler choice, glow plug choice, temperature, humidity, altitude, and many others, can make a difference of as much as 3/4 of a turn on the needles.

There are a number of good posts on this site explaining how to tune the needles.

There is a good chance that your wag is from the engine.

[Deano]

Well, it still wags after tightening the tail vertical fin. I bought this engine 2nd hand and I am beginning to wonder if there is maybe a problem with it. Does anyone have any suggestions?

[flyinfool]

Have tried tuning the engine yet.
Is it possible to post a video of the wag so that we can see and hear what it might be?

[Deano]

I'll try to get video but what it is doing is wagging about 2 -3 inches one way then the next second, 2-3 inches the next. I have tried tuning a little but weather has been a problem.

[Deano]

I have dropped a different engine into it and now currently waiting for the wind to die down below 30mph to give it a shot..... Could the gyro or the tail servo cause this?

[Deano]

Okay, new engine in heli and same wag!!! What is junk the servo or the gyro, any guesses??

[Deano]

I did notice that the linkage to the tail was somewhat touching the main gear. I have changed to a boom mounted servo and will try it out as soon as I get a chance.

[flyinfool]

What are your end point (E.Point) settings on the rudder channel in the transmitter?
What is the travel set at on the 401?
What is the delay set at on the 401?

[Deano]

Delay is 0, it is paired with a 9254 digital servo. Travel is 100% and does not appear to be binding.

[Deano]

Did a test fly with servo mounted on tail and same thing. I am noticing that the main gear has a definite high spot when I turn the blades using the main gear. Could this cause a side to side wag? When I first got this thing I went thru 2 main gears before even getting it off the ground. :dontknow

[flyinfool]

A high spot could cause a vibration but not likly a wag.

What are your end point (E.Point) settings on the rudder channel in the transmitter?

[Deano]

I have had the HH setting set on 65% all the way down to 30% and getting the same results.

[flyinfool]

I am not asking the gain setting, what is the endpoint for the rudder channel set at?

[Deano]

Channel 4 endpoints are +- 100%

[Deano]

I have a Hitec 925mg high speed servo. Would that be okay to try in the tail?

[flyinfool]

You could try that servo, it will work, but it is NOT digital so you must turn off DS on the gyro.
Also you must check the direction to be sure that left and right are still correct in both the TX and gyro, I think Hitec has a different direction of rotation than Futaba.

[Deano]

It does. I am ready to test, just waiting on the wind to die down a bit.

[WJackson]

I'll try to get video but what it is doing is wagging about 2 -3 inches one way then the next second, 2-3 inches the next. I have tried tuning a little but weather has been a problem.
Can you define this a little? Is it a kick to the right 2-3 inches (nose left), does it correct back the difference? next step is to obviously swap 401's because with the exception of the engine being tuned incorrectly (I dont own a c-spec but have seen many a person scratch there head with one, after they got the needles right, gravy, but until then :arggg: :arggg: ) Sometimes these things make ya wanna :bomb: , but you'll find it.