Hi

Today was no wind at all and I noticed, when I hover and fly slowly forward(Nick) the Heli drifts 45 degree(Roll) to the left. Do I fly backwards its drifting 45 degree to the right. The faster I fly the lesser the drift. What could be the Problem? The tail stays in position.

I did all the swashplate settings very precise with an digital pitch gauge.

Where could be the problem?

Kind regards
Jens

Hello,

I am afraid but according your description it could be caused very likely by two possible things:
a) Trims in a radio - all should be at zero. Possibly there is some trim in a flight mode only, while for Hold there is no trim.
b) There are extremely high vibrations. You can check it with a Vibration Analysis. The most likely problem is in a tail mechanics, but the analysis tool will tell you. I recommend to measure Y axis with tail blades on - but very carefully. Before entering the Vibration Analysis tool please center tail servo so there is 0° between tail blades.

_________________
Spirit System developer

Hi thank you for your response.

I will check the y axis the coming days. Just had a quick look at the logfiles and my overall vibration level is mostly between 14 and 21 but in every flight is one peak with 28-29. Is this still okay?

Like i said i will check it as soon i have time.

Kind regards Jens

Finally I had some time for further checks.

Trim in the TX is 0 and disabled.

Vibration level for Y is okay. (Heli on the bench without main blades but with tail blades)
Bank 0 : (Hovering 1450rpm) max. 30
Bank 1 : (Flying 1800rpm) max. 60
Bank 2 : (Landing 1350rpm) max. 25
When I lift the Heli the vibration level drops by 5-10.

But I noticed when I use Bank 1 and increase the rpm just by 10% the vibration level skyrockets up to 125.
Still I have the drift in all three banks.

Here the Vibration level pics. ( Heli on the bench)

Hi

In the meanwhile I tested again the Vibration level again but its low. I flashed the spirit new and did only the standard settings. I was very careful during the swashplate levelling to get it precise as possible. The drift that I explained is still there.

This time there was a little bit of wind from the right side. Flying backwards the Heli driftet still to the right against the wind.

An other thing is that when I do a stationary pirouette the Heli drifts to the right again against the wind. Even if I give a small roll impulse to the left so the Heli moves to the left and do the pirouette the Heli moves to the right side.

I have no clue what to do anymore. A friend thinks that the Sensor inside the Spirit has a problem.

Is there anything else that I can test to find the problem?

Kind regards Jens

Hi

Just did a test flight with my second Heli a small Protos 380 Light V2 also with a Spirit GT and this Heli has the same behaviour.

flying slowly forward has only a small drift to the left but backwards has the same drift like my Kraken 580. And pirouettes left or right are again always moving the Heli to the right side. Is this normal for pirouettes?

So I don't think that is a problem with the Sensor.

Hello,

if model drifts just little bit it is OK. Stabilisation mode will not stop movement of the model.
Only when GeoLink Position Hold is used, it will stay stationary. During pirouettes it is very dependent on how precisely swashplate was set. Also it depends if tail mechanics is positioned precisely. With some models tail can be rotated to add force also vertically, which causes movement. But usually it is not a problem.

What is your Spirit unit?

The drifting could be also result of a wrong configuration of parameters such as Mounting Position, Swashplate Type or Reversing or combination of these. Model can fly seemingly well, but stabilisation will work very poorly.

Could you take a photo of mounted unit on the model? Then I can verify also these parameters.

Vibration plots looks great, but have you tested it with tail blades?
If not, difference could be even 100x worse. Usually it is 2-4x worse.

_________________
Spirit System developer

I use a Spirit GT in both Helicopters. The drift is not while hovering stationary its when I fly slowly forward or backwards. The stronger drift is while flying slowly backwards. I don't use the Stabilisation mode at all, don't like the feeling.

The shown vibration scann is fron my Kraken 580 with tail blades. The vibration level is so low that I have several logs from one flight. I'm always happy if I find a log of 2-5min during a 12min flight. Most logs are only a few seconds. My second Helicopter is an Protos 380 light V2 and the vibration level is a bit higher than the Kraken. I get proper logs from every flight.

In both cases the Spirit unit is mounted with the plugs showing to the front. I used the original tape. I was very precise while setting the swashplate.

What is the best way to position the Tail? I always position it exactly in the middle. So I get the same travel distance to both sides.

Sorry for the poor pics.

Here the Protos pics.