mikehannah

Hi
I just test flew my Wind 110 today and to get her to fly I had to put in a surprising amount of up elevator trim( about 1/8th of an inch). My CG is towards the back of the recommended range,and she doesnt feel nose heavy. Didnt do much Aeorbatics as I was being kind to my brand new packs and I didnt fly her inverted to see how much down elevator she would require but judging by the elevator I am think it will need a bucket. ( I prefer just gentle pressure myself)

Has anyone else hit the same problem and if so what did they do to cure it. I am thinking I need to reduce the amount of Down thrust.

Mike

Lnewqban

You may find a good reference here:

http://www.seniorpattern.com/pdf/Kir...im_article.pdf

mikehannah

Hi
Wasnt alot of help, Anyone who is flying the Wind out there had the same problem?

Mike

1bwana1

Check the incidence of the wings and stabs before you make any changes.

woodie

I agree, sounds more like a wing/stab incidence issue. Downthrust doesn't have that much effect at cruise speeds. It will induce minor pitch changes with throttle changes but probably wouldn't be the primary cause of your elev trim issue.

Woodie

mikehannah

Hi
Unfortuntaley the Wing and the Stab incidence is set and I cant change it. Both the Wing and the Stab plug into recessed area of the Fuse and even minor changes would involve alot of hacking. Which I dont want to do unless I know for sure I am on the right track.

Mike

tIANci

Mike ... mine is just ever so slightly nose heavy, very light touch when inverted. The elevator is about level with the stab. I never really bother to follow the recommended CG other than for the maiden. I think I am at 190mm for the maiden, after that I took the batt a little further back so I am guessing almost 195 now. Its a guess!

Anyways, what is your set up again? With the Scorpion and 10S 4,900s, the back of my batts are just in front the last lightening hole on the tray.

mikehannah

Hi
Not sure where my cg is exactly. Like you I set my cg as to how the plane feels to me, but I will be surprised if it is any more forward than 180mm.
I am flying the stock Hacker set up on 8s 5000mAh cells. The battery back is as far back as i can get it. The Rx battery is sitting on a platform above the rudder servo. It needs about 3mm of up elevator to get it to fly straight and level. No idea how she flies inverted as i didnt get the time to explore the envelope.

Mike

tIANci

Try balancing her and mark it to see where the CG is ... if she is nose heavy she will come in nice and hot, how are the landings? Mine is like just floating in slow enuff. Almost like a trainer!

mikehannah

Hi
She flies like a well mannered aeroplane. Dropped her within six feet of me with my first landing, noproblems slowling her down or controlling the speed during the decent. This is NOT a nose heavy aeroplane.

Mike

huison2005

mikehannah , me too have the same probleum ..... the elevator is up by 2mm , as you can see clearly at the tip !

Just got my Hanger9 digital incedent meter will check it out . . . .!!

f3a05

I'm not too familiar with the slightly smaller pattern planes, but am I right in thinking that it's a Sebart ARF?
Just asking, because from what you're saying, it does sound like an issue with (probably) too little positive incidence on the wing,relative to the tail.
A club colleague,who is thorough in such things, has/had(not sure which) one of the smaller Sebart Angel S models (S50?),which initially needed a lot of up elevator trim to fly level,and,although I don't recall the numbers, it had negative wing incidence as assembled out of the box.
He did actually hack it about,to get some positive onto the wing-and of course the need for up elevator trim went away.
To give Sebart their due, (I believe Seba himself sanctioned it),the UK distributors did supply another one FOC.

tIANci

F3a ... There were some guys who complained about the Angel with insufficient incidence on the wing. Remembered that one. It was on RCU too I believe. Guess just have to check the amount of decalage on the Wind S.

2Sunny

I was one of the guys that worked on the incidence problem with the Angel 50. I built two planes and corrected the incidence to 0/0 on the second plane, but could not discern any change in flight characteristics between the two setups. In fact when I let a "pro" fly both, he felt that the original unadjusted wing setup may have had a slight edge. All that is to say: Would you consider flying it a few dozen times and then reporting back on how it trims out as is? I'm dyin' to hear more about this plane! Also, do you have any pictures of how far out the elevator is trimmed for level flight?


Joe


[link=http://www.rcuniverse.com/forum/fb.asp?m=8053712]Angel S 50 Incidence Issue post[/link]

mikehannah

Hi
It is my intention to keep flying the plane unless the elevator is unmanageable. I will keep people posted as too my progress. What I can say is that the stock set up has bags of grunt and the loop I pulled with it was remarkably true considering i didnt consciously trying to keep it straight.

Mike

tIANci

Mike ... imagine 10S ... hehehehee

Jeff Boyd 2

The Wind I flew is a 10S set-up . . and it is AWESOME !

He also tried a 12S set-up in it with a AUW of nearly 5kgs. This was just a test for windy conditions, it was tested in approx 40kmh winds, and worked really well . . . . THEN, I told him about the F3A rule of 42.56V Max. for the propulsion circuit . . SO back to the drawing board .

Cheers, JB

tIANci

JB ... I am on 10S with a 17x8 (only about 55A) ... soon will get the XOAR 18x8 ... that will be fun!

Jetdesign

My Feedback: (8)

Mike, any updates on the elevator trim?

huison2005

i just check with incedent meter last night , surprisingly the wing n stab are 0 .... motor trust is -2.5 ....!

What about you guys out there .... same as mine !!??

mikehannah

Hi
I have not been out to fly mine since I test flew it. Work commitments etc getting in the way. Everyone seems to have the same problem of needing a little up elevator to get the plane to fly straight and level. To me this is ridiculous, the plane should have been designed to have zero trim required ( cg permitting), however from the limited flight experience I have had with it, it didnt seem to balloon when you suddenly chop the power. So that indicates the down thrust is about right. Go figure?

This contrasts with my now dead Angel S that needed no trim at all except one click of left aileron and only a gentle squeeze of down elevator when inverted.

I will know more when I get it back in the air and get to explore the flight envelope a little.
It does look gorgeous on the ground and in the air but I would have expected more from a Sebart plane and would make me think twice about spalshing the cash for it's bigger brother.

I await the flak.

Mike

Jetdesign

My Feedback: (8)

Some other tests to do:

Fly straight and level and pull into a vertical up line. See if the model pulls to belly, canopy, or flies straight up. This is another test for thrust angle. Pulling to the belly would indicate too much down thrust.

Power-Off vertical dive. Again, note if model pulls to belly, canopy, or falls straight down. This is a test for the incidence. If the model pulls to canopy, it shows a need for in increase in wing or stab incidence.

Knife Edge flight: Another test for incidence. If the model pitches to the canopy, it displays a need for an increase of wing or stab incidence.