Please help, Logo 400 tail wag

[galensk]

Hi,
did youresolve the slop in the swash servo's already ? mine did the same thing and especially if you give collective input this will result in a wag for tail after the wobble.

this is more expliciet on lower HS. i also tried the harder dampner set in the rotorhead but this didn't make much difference

kurt

[Primus]

Not yet. Will do. What type of plastic have you used, please. Thinking of some shrink tube on the interior servo shaft.

The slop should'n make any difference on horizontal piroueting.

IMHO at right turn or sudden pitch change the tail rotor is becoming less efficient and the servo/gyro is over compensating.
The big question is why.

Looking for some 9650 for the new kit comming. I think that i'll let on this kit the Align servos and move on Futabas for the new one.

[galensk]

Originally Posted by Primus

Not yet. Will do. What type of plastic have you used, please.
Thinking of some shrink tube on the interior servo

It is very thin plastic sheet cut from the cover of a "yohurt" box, heat shrink turned out to be to wide. I found on the forums a theory that says the savox / align servo potmeters are sensitive to framevibrations and steer the servohorns wrongly. this may cause the vbar to overcompensate, just a theorie I found and mine doesn't wobble anymore since I placed some shim along the potentiometershaft of my servo's. This is to my knowledge not reported or experienced when using the Futaba 9650's

anyhow, the swash and tail servo shouldn't move if you spoolup without blades on the bench

Don't give up... I flew a few packs on the 400 today and it's worth the effort !!!

kurt

[Ricci]

Did you finally reduce the flight vibration levels with all your fine-tunning? Vibrations may also induce to tail wags.

My other advice is to try different tail blade pitches (tipically around 3°) at 90° tail servo horn, I've got different results working on different positions.

Finally, the BLS251 also helps a lot reducing or supressing the tail wag, it is a much better servo than the Savox DS620, even if you don't see a lot of difference on written specs.

Ricci.

[Primus]

Hi Ricci,

I think I have an acceptable vibes level on it . Still i want to find the mechanical issue who is generating this wag.

Dumb question, I could get away with this by simply replacing the plastic blades ?? Waiting some Edge tails. Thanks

In hover last vib analyse:

[galensk]

Hi there,

any progres on the wag problem ?

Kurt

[Primus]

Yeah Kurt!
Crashed last night as I've lowered the gain too much and had a tail blow.
Hope this will eliminate the wag.

Blades, boom, tail fins, some servo gears, and the battery tray cracked. Fusuno rules for theirs canopies strenght!


I have eliminated the litle slop on the servos by the "yogourt method" (thanks), remounted all the servos, same issue. As I see the frame bobbing on low speed, I'll check the spindle as soon as the new shafts are comming.
I hope is not the head itself.

Flying my 500 ATM.

[galensk]

Ooops ! Sorry to hear from the crash...but at least you wil have to rebuild hopefully without the wag...

good luck and keep us posted !

Kurt

[Vince_be]

Hi,

Check that bearings are perfectly seated in main grips. I has the issue and it gave wobbles on the frame.

Regards.

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[Primus]

Coming back to this thread, my tail is much better now,
I still have some wag issues, i think is about setting up the correct gain value. I'm at 69 right now and I still see some wag on strongs loads.

Running atm at 2600 RPM, Vbar gov.
9650/DS620, ICE100, 3026-1400/18T, stock gear

Switched the motor, pinion, servos including tail one (9257, 9254, DS520), boom, axes, head, maingear, autorotation hub, belt, pulley, dumpers, and blades ( crashed four times lately).

Would it be possible to share some tail gain values for your Logo 400, I know it depends of alot of things (speed, tail servo) but still good for comparing.

Thanks

[galensk]

hello Primus .
good to see you back ! crashed 4 times so what are you learning ? meanwhile I sold my logo400 and fly the 500 all the time, despite the horrible weather over here...

I can mail you my 400vbar setup files somewhere tomorrow morning If you like too. should be enough to compare, don't you think ?

[Primus]

Hi galensk

Yes, last time today, the spektrum sat died and let me with out controls ( still had solid light but out of synchro). Learning half piro flips atm and funels. Slow learning curve.

Rebuild it in a half an hour and then emptied 6 packs at the of the day.

Thanks for sharing your setup.

Hope you will have soon some good flying wheather there.






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[galensk]

Here you have my last "working" VBAR file. For what its worth...

[Primus]

Thanks for sharing Kurt
I've done 3 packs today with a gain of 63, 65 ( real tail gain value on the vbar software).. It seems to be a good value for my headspeed. NOOO wag!!! He he :-).
I was using before 80, 76, 74.

PS: Dropped the I gain from 60 to 55

Is there a fixed value on your file ( i mean you dont use the aux-to-gain funtion?) If not what was yours, if you still have this in mind?


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[galensk]

My gain was always fixed I used bank switching with my aux channel but didn't change the gain value...

[Primus]

K thanks I will take a look at your numbers.

16 deg here and sunny. Great flying conditions. :-)

I have a great time with my new mcpx bl too.


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[galensk]

Originally Posted by Primus

K thanks I will take a look at your numbers.

16 deg here and sunny. Great flying conditions. :-)

I have a great time with my new mcpx bl too.


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-10 over here and 15 cm snow .... I also bought the mcpx bl recently and this isnhelping a lot to improve skills. did you try to piroflip the mcpx bl yet ?
kurt