ATV or Pmix for Fury Extreme Interaction

[Knud Pedersen DENMARK]

I have been reading some tropic regarding interaction on the Fury Extreme.
I have also seen the DavidH “Setup video”.

I have installed Futaba Big Servowheels perpendicular to the servos (when the servo is at center, no trim, no Subtrim)
Then I have adjust the ATV, so the swashplate is level/perpendicular to the mast (with the swashplate alignment tool), ATV goes from 97% on one servo, and 104% on another servo.

BUT when doing stationer flips, the heli is leaning a bit to the right when passes through the inverted section (I must give some left ail correction)

Now I have been told not to change the ATV, but to use Pmix (pit->ail and pit->ele).
Now I have set the all swashplate servo ATV´s to ±100% (in idlup2).
Then I hover upright/inverted, make a climpout, and check if the Pmix I OK (lift of straight).
I´m also trying some loops to see if it is on tracks…..

Question:
- I there is no wind, and the heli is setup correctly, would it then in ex. Stationer Flips, stay level?
- Do you use ATV or Pmix to trim for any interaction , and why.

ChopperKnud

[DavidH]

I use ATV's to make sure the Swashplate is level at max positive and max negative pitch. I have also used a Pmix, but from my experience. Usually the swashplate is usually only out of synth at the extreme ends of the travel.

Try both and see which one works best for you. If you use a Pmix, you will most likely need two. Collective>elevator and collective > aileron.

David

[Knud Pedersen DENMARK]

Is it possible to trim (use ATV or 2xPMIX) on the bench – meaning if the swashplate is ABSOLUTLY perpendicular to the main shaft in the hole Pitch range – would the heli then fly superb – or is it always necessary to fly and then adjust the ATV / PMIX?
:?: :?:
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Note:
Now I have tried using ATV or Pmix to adjust the interactions.
I find it easier to use the 2xPMIX if the interactions is adjust at the flying field – because if the heli ex. Goes to the right at full pitch, then simply adjust the Pmix Pit->ail.
If using ATV it might be necessary to adjust ATV on two servos…

ChopperKnud

[DavidH]

I use ATV if the interaction is happening only at full negative or positive collective.
Usually I have found that is only place the interaction takes place. This is due to one servo traveling further than the others.

I make the swash level on the bench with ATV at the extreme collective ends. Then I go out and fly the heli. Most of the time if it doing something then, it could be balance of heli or another item causing the problem.

David

[Wayne]

I make sure all my ATV's are set to 100%, and make sure all trims are neutral. Then, at mid stick or zero degrees pitch I make sure the swashplate is perfectly level. If it is not, I make that adjustment mechanically. Then, at both max and min pitch I use ATV's to insure that the swash is level at those positions.

Most important, this changes. I check mine every few months, and sure enough it is out of whack on the ends. Don't ask why, we've been trying to figure it out, but with the 9252's they seem to age or something.

Wayne

[WillJames]

The other thing to keep in mind is how the heli flys. No matter how perfectly level you make the swash on the bench when you fly it you MAY still have to adjust your ATV's to make sure it climbs straight up inverted and right side up at full positive and full negative.

Go out and test and if the heli pitches or rolls at all duing a full stick upright climbout or a full nevative stick inverted climbout you will need to adjust your ATV's to make sure it stays level and flat. Once you do this final step the heli will fly like a dream and the interraction should be minimized.

[Dr.Ben]

As Wayne noted, 9252's change soon after installation and continue to do so over the life of the servo. They also do it inconsistently from one servo to another within the set of three in the model with the same amount of time on them.

As long as there are carbon wiper potentiometers in our servos that wear in over time and indirectly driven pots, setups are going to shift with time. It's the cross we bear with eCCPM.

It has gotten better though. 9255's track and hold set up much better than 9252's.

Ben Minor

[Knud Pedersen DENMARK]

Okay – did I get it right ? :( :

I will use the ATV to make the swashplate level (on the bench)
Then go flying, make some upright/invertet vertical climbout, adjust the ATV so that they are straight.
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Then do some roll, and maybe use some P-mix to get those straight (?)
And maybe use some P-mix to get the flip straight (?)
Use the P-mix for fixing cyclic-cyclic and cyclic-pitch interactions(?)
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:mrgreen: ChopperKnud

[Rodney]

Dr.Ben Thats the first I have heard of that. Wearing 9252's So what has changed in the 9255's?

[DavidH]

Rodney,
On eCCPM helis and 9252's it has been known for long time. That after they are in operation for a period of time , that the neutral will shift. I have been using 9252's since they became available on eCCPM setups. After they are installed new, usually after about 25 flights I have to go back and reset the wheels on the servos because the neutral would be shifted. Usually have to do this again after about another 50 flights and then they will go quiet a while sometimes without needing adjustment again. Been this way on all the 9252's and eCCPM setups I have done. Also Ben , Gordie, Wayne Mann, Dwight Shilling and number of other pilots that use 9252's on eCCPM helis have had the same experience.

David

[Dr.Ben]

Rodney,

I'm not sure what collection of things that Futaba improved on the 9255's, but they certainly hold an eCCPM set up better than the 9252's did. They also have the first metal geartrain that I've personally flown on a cyclic/collective application (IE non tail rotor) that has stayed reasonably lash free over the long haul. They really are killer servos.

Ben Minor

[Knud Pedersen DENMARK]

What are the difference technical data (speed, force, size etc.) between the 9252 and 9255??
IS the 9255 going to be the new “super servos” for helis – like the 9252 was, are?
:shock: :shock:

ChopperKnud

[WillJames]

Knud, Yes setup level on the bench using ATV's as long as you can do it with just ATV's. My Extreme (due to my old 9252's I guess) needed a P-MIX as well to keep the swash completely level on the bench. Then it also needed the swash trimmed after flying with ATV's to keep the heli flying completely flat and level in max + and max - climbouts. Now it is flying great!!

My Ion-X with new 9252's just needed ATV's and no P-MIX at all on the bench and also flying.