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[SOLVED] tail wag and rescue to backwards on a Trex 450L

Posted: Mon 23. Mar 2015 1:17:49
by pabloK
Hi

can you help on the gyro and others value in order to make tail wag dissapear.
I get this tail wag in right turns and in high speed forward flight.

all value are at defaults

i tried gyro from 60 to 29 and the same issue

The rescue (normal) get up and backwards.

thanks

Re: tail wag and rescue to backwards on a Trex 450L

Posted: Mon 23. Mar 2015 17:01:00
by ZeXx86
Hi,

you can try to check rudder neutral position, how it is configured right now?

Also you can put ball link closer to the center on the servo horn.

What is your current Piro Consistency and Rudder delay value?

Re: tail wag and rescue to backwards on a Trex 450L

Posted: Mon 23. Mar 2015 19:39:10
by FrankFuss
ZeXx86 wrote:Also you can put ball link closer to the center on the servo horn.
The Align 450L stock rudder servo ball link location is 10mm from center. This is too far out. Between 8mm and 7mm is better. At about 8mm I got Rudder end-points of Minimum limit: 94 and Maximum limit: 100.

Re: tail wag and rescue to backwards on a Trex 450L

Posted: Mon 23. Mar 2015 20:34:44
by pabloK
you can try to check rudder neutral position, how it is configured right now?
I dont undesrtand this question, what value do you refer? is neutral at 90 degrees!

Also you can put ball link closer to the center on the servo horn.
Ok

What is your current Piro Consistency and Rudder delay value?
rudder delay is 15
piro consistecy is 150

any other data?

thanks

Re: tail wag and rescue to backwards on a Trex 450L

Posted: Mon 23. Mar 2015 20:38:01
by ZeXx86
I then recommend to also set Piro Consistency to 160, Rudder Delay to 8.

What rudder servo do you use?

Re: tail wag and rescue to backwards on a Trex 450L

Posted: Mon 23. Mar 2015 21:23:31
by pabloK
the one that comes with the kit. align DS525M

Also, analizing vibration, I have high ones in all axis. this is common in this kind of 450L heli that is so powerfull?
Its NEW, right out of the box and it is almost the 10 heli I assemble.

What about the rescue that comes up and backwards?

in the bench seems ok !!!

Re: tail wag and rescue to backwards on a Trex 450L

Posted: Mon 23. Mar 2015 22:20:38
by ZeXx86
Can you please post Graphs from vibration analysis? Especially Y - aileron axis.
If there are really big vibrations it may cause bad perfomance of the helicopter generally including rescue.

Re: tail wag and rescue to backwards on a Trex 450L

Posted: Tue 24. Mar 2015 0:14:57
by pabloK
all axes at 90 % throttle and NO BLADES at all

in some points, graphs down to 45% aprox, but i cant reproduce again this. I tried several times and almost always vibrations at 70%

i am using a foam pad from the TAROT ZYX-S2, maybe this is some problem too?

thanks

Re: tail wag and rescue to backwards on a Trex 450L

Posted: Tue 24. Mar 2015 21:44:51
by pabloK
Hi

I change the anti vibration foam pad for the spirit (the one that cames with the second unit I bought recently, the first unit doesnt come with it)
Please, see the new graphs for 3 axes at 90% throttle. change absolutely !!! now is in the range !!!

Re: tail wag and rescue to backwards on a Trex 450L

Posted: Tue 24. Mar 2015 22:41:39
by ZeXx86
Oh nice, it is much better now.

You can try this again with tail blades to measure it more precisely. Sometimes tail blades can make big difference.