Hi guys, I need a bit of advice.

Today I was fighing my t-rex 700 dfc with Spirit 2. ver 3.5.0.

On the initial fight, all is well, even with idel up 1 and 2. But after some soft acrobatics (rolls, loops, etc.) and a constant inverted without crazy manoeuvres, I put the heli back to normal skids facing ground, but the heli started drifting to the left (my left) at the point I was thinking was the wind, but it was just so bad that I had to try to land in 3-4 attempts with a hard landing. When I say drifting, I mean trying role to the left. If I don`t correct the drift, the heli will do a role left...

I hope I make myself understand.

I have to say that the heli was not flying for some months but was fine the last time I used it.

I managed to save the model by coincidence; it was a scary landing because, when using the rescue at the landing to help me on the attempts, the heli keeps drifting on rescue too.

Now I made normal checks, and I did not find anything mechanically wrong. Also, because it was flying well before I started the acro and inverted manoeuvres, I checked the diag on the spirt, but nothing came back from the diag log apart from the tail limit reached....etc

I checked the double-sided tape (3M) that came originally with the unit and it seems solid. (bit old but ok) So I believe it's a software problem?

is leke the unit was tild to the right and the unit was trying to compensate to the left.

Any advice will be much appreciated.

Theo

... do you have (by luck) a log of the vibration level of the heli? and a log of the inputs (sticks/channels). vibrations or non-centered sticks/channels (maybe even sub-trim?) are 2 easy reasons for such a drift.

if it only is visible after some minutes of flight, you may even need to check all this after flight - do not switch of the heli, check channels in diagnostics page - all still centered? and - of course - vibration log in flight.

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cheers
Michael

Hi No logs for the vibration, as I was not really checking the vibrations on the last flight.

I will try to make a test on the bech for vibrations, as this heli has a speed fuselage, but I never had issues like this.

Following ZeXx86's advice for other pilots, I enabled Extended Signal Processing after discovering via forum reading that other people have experienced similar problems.

viewtopic.php?f=20&t=5786

I do not know the difference between the two settings for the best performance on this page:

https://manual.spirit-system.com/index. ... ise_Rescue

There are two parameters that can greatly improve the reliability and precision of the stabilisation andrescue modes:

Stabi Correction and Extended Signal Processing

Both can be found in Advanced-Expert Settings.

While making some tests, I noticed that on the bench, if I activate the stabi, the heli will tild just a little bit to the right.

Theo 

yes, check the vibration level... there are several reasons for vibrations of a heli that has not been used for a while (dried dampers, dead bearings etc etc ppp). and check sticks middle point after flight if it should drift again. those are points to be cleared out easily if found. and: do you use a Esc fan? some of those are creating super sonic vibrations that may cause issues like drift too (esp. HW fans).

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cheers
Michael

to reduce vibrations on my trex it worked well changhe the dumper rubber and the double-sided tape under the control unit.
also the electrical clamp with heat shrinkable sheath which maintains the spirit decreased my vibrations by 50%.
I have a photo of the goblin but I also have on trex

Nice one thanks.
Will replace the old original double side tape and test your method.
Thanks

Theo

Sent from my SM-N986B using Tapatalk

I do not recommend using a cable tie. I also highly recommend using original double sided tape - only one layer.

Please use Spectrum Analysis tool in the software. This will help you to find if there is vibration problem or not.
It is best to measure with tail blades on, because problem is usually in the tail mechanics.

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Spirit System developer

they usually use a bioadhesive very strong but very hard, I found a bioadhesive less strong but very soft it is made of a material spongy and this bioadhesive it solved the problem of vibrations.
But I assure you that if there are vibrations It means that there is a component that causes you vibrations.
Look at that spirit software It has a vibrations function and you already need to isolate the vibration in 3 points:
main rotor
tail rotor
motor
Run the helicopter with the software turned on
on the table to understand where the vibration is
those solutions diminish the problem but you have to find the component and change it anyway