Tension on battons

[Brian]

I replaced the bungi cords on my Aquilla 1 wing a few months ago and it turned my wing into a nightmare.To maintain level flight I had to seriously force the wing into a forward position but after releasing the tension on the cords it seemed to alleviate the problem.Lately the wing has a tendency to roll to the right and I replaced all cords again making sure they are exactly the same tension and once again I need to force the trapeze bar forward for level flight.
Is there a rule of thumb tension on the batons or do I have a more serious problem?

BTW, the bungi cords are not excessively tight

[Wargames]

Hi Brain,

I am struggeling with almost the same issues at this stage with my wing, although not quite as exessive.

Anyway, I phoned Aiden from solowings to get some help, and according to him, the tension of the bungies only affects the speed of the wing. The tighter your bungees, the thighter your wing sail and the faster you fly. opposite also true.

But now, what will happen if your left side bungees are tighter than your right hand side. My opinion, your left side would be faster with less lift than the right hand side, hence a tendency to roll to your left?? Is this true??

Did you set the profile of your battens??

[Brian]

Not yet Wargame
I dont like to scratch if it aint itching but it does make sense to check the profile.

Problem is that when I bought the trike the wing was perfect untill I followed advice and replaced the cords.

[Wargames]

I had to replace bungees last your as part of my anual inspection. AP wasnt happy with their condition, and they were very old. That didn't change my wing when flying, although I am starting to think that it did, and hence my problem. My suggestion is to get a AP out to check your wing through, and if possible, fly it. Where are you flying from??

[Brian]

I am based in Bloem.

I will get the AP out and hopefully resolve the problem.

The problem arose again this afternoon and I will only sleep better if I know why but apparently all good things come to those who wait.

Thanx for the reply though.
I will let you know the outcome A.S.A.P

Regards
Brian

[Wargames]

Hi Brain,

I sent you PM.

Regards,

[gertcoetzee]

I replaced the bungies on WUO on Saturday, and find that the wing is definately faster (by about 5mph) and got the feeling that it drops a bit on the right, so will curve the batons on that side.

[kloot piloot]

Gert, before you start "tuning" your battens, rather decrease the angle of attack on your left wingtip cup, or increase aoa on the right wing tip cup. Only if that does not work should you start tuning battens.

[Trikenut]

Louis VW had to sort out a roll on his trike and all he did was bend the batons of the side it was rolling to, so that the curved batons would produce more lift.

[kloot piloot]

Bending battens works. However not every one bends the right battens at the correct centre of lift area. For that reason the tip cups are installed. Look inside the wingtip and you will see that a reference line (on Aquila a permanent marker line) is drawn between cup and leading edge. The slightest adjustment there has more effect then starting to change the pairing of left and right battens.

Example: Bend battens on right now. Trike gets sold. New owner new bungees. Arguement-sakes the trike now turns in the opposite direction. He bends battens on the left.

Eventually you end up with a wing still flying straight, but with a completely deformed aerofoil section, less performance and stall characteristics way out of the standard envelope.

One should therefor rather remove all battens and conform to the batten profile chart, and start afresh with cups, and as a last resort start to tune battens.

Let us know what transpires. Eager to know.

[AndyG]

Yes Kloot,

Rather phone the manufacture and get the profile baton chart or get an AP who knows his stuff on adjusting batons.


Cheers,

[Trikenut]

Hi,
Louis is very experienced in the Aquilla field.
He knew EXACTLY what batons to curve. The end result, the wing flew like a dream (I flew a bit from the backseat) and it didn't look deformed at all...

[kloot piloot]

Glad to hear you are sorted.