Eagletree Vector Gains query on Skywalker 1900

[Antkol]

Hi everyone.
I have used the Eagletree vector in my Bixler 1.1 and it has worked like a dream with no problems, instantly auto levelling, and doing everything that it should.

Now I have it in my Skywalker 1900, which admittedly is a much bigger heavier airframe.  I have noticed that when in a 2d hold mode or even 2d no hold mode it is slow to correct yawning, rolling and pitching.  Although it will on average keep a steady course it resembles a drunk on a Saturday night.

I have convinced myself, although I may need your help, in assuming that is is all down to the gain settings in the Vector.  Does anyone have any similar experience, or what gains I should be using for this airframe.  Or maybe it's not gains and something totally separate.  My CG is correct.

Any help very gratefully received as I have never really altered the default Vector settings from new.

Kindest regards

[BlueFlyer]

what do you have your stabiliser responsiveness set to? too low and it will just wallow around.

Also, it is my experience that 2D Hold doesn't play nice with the skywalker 1900 anyway. I can only get my skywalker 1900 flying with the wings level in 2D no hold mode.

it's down to the design of the skywalker, they're famous for not being "straight" so to speak. even with all control surfaces perfectly level, the tail is usually out of whack and causes unwanted yaw and roll issues.

Take into account that the 2D Hold mode is actually not trying to keep your plane level, it's trying to keep your plane flying in a straight line as the crow flies. If your subtrim on your rudder or ailerons isn't perfect, or your tail isn't perfectly straight (which it won't be, even if it looks it) the autopilot has to counter those imperfections in order to keep the plane heading in a straight line and it will not "look" like it's flying straight, it will be tilted to one side and will be crabbing in the direction of flight.

once I changed the switch position to 2D instead of 2D hold in the software, the wings would then level perfectly, albeit with a gradual left turn due to tail imperfections. I manually dial that out using rudder trim in flight, as the severity of the turn depends on my airspeed.

[dogzilla]

The problem with heading hold is that it uses ailerons and to fly a Skywalker in a straight line you need to use the rudder.

I have the same issue with my RVOSD. Instead I just leave it in stabilized and then trim the rudder.

[BlueFlyer]

The problem with heading hold is that it uses ailerons and to fly a Skywalker in a straight line you need to use the rudder.

I have the same issue with my RVOSD. Instead I just leave it in stabilized and then trim the rudder.

yes this!

I couldn't get my head round why something as "advanced" as the Vector would not simply LEVEL the plane using ailerons and adjust course using the rudder.... but it doesn't :(

[Antkol]

Hi guys
That is very interesting regarding the 2d hold on the skywalker.  The bixler seemed to work with 2d hold no probs, but I am guessing that as the ailerons are doing the steering on this mode then it takes that bit longer to correct the change in direction.

I have increased the gains to 60% from 50% and increased the stabilisation from 5 to 6.  I shall see if this makes a difference and report back....

[Antkol]

Ok.  I have had a half hour flight and can report back a couple of things, all in 2d No Hold.

The wind was a little gusty and a bit blowy for me - about 20-25mph, which when flying below 100 feet seems to make a big difference to handling.  At the height and below the SW was twitchy and buffeted by the gusts ( I guess this is ground effect) and the whole experience was a bit hairy at times.  Anyway things calmed down above 250ft - this may be because the wind was more constant and at 600feet, she was just motionless in the sky - literally 0mph over the ground and steady.   Snapped much quicker out of a dive and at that height the wings kept level.  Down wind she zipped along at 55mph over the ground at 4.5 amps (hence my approximation on wind speed).

I did find that I needed to trim the rudder like you said.  I think I can conclude that the SW is harder to fly than the Bixler in bustier conditions but a joy in steady or still winds.  The main benefit however is the ability to carry more gear for aerial filming which I intend to do come summer.

Anyway, I know you guys are much more experienced in the SW1900 so if you have any further tips and advice, it is very much appreciated.  I may tweak the gains again...
Kind regards
A


Overall now happier

[Antkol]

Just to give a final update.  I have tweeted the gains on the Vector and now the SW1900 is flying like a dream. 
For the record I have all the gains set to 65 ( up from factory default of 50) and stabilisation setting on 6.   If I load more gear onto it I may have to revisit this but for the time being, it is flying really well.
Cheers for all your input.
A