Flying wing doesnt want to stay in air

[Boiii]

Hello. I have a problem. i made this flying wing and it flies really weird. It oscilates really bad. What could be the problem?

 

[Boiii]

Here is link to video :

 

[Piotrsko]

Video doesn't give much help, could be on edge of stall, local wind eddies, lousy CG placement, neighborhood radio interfering or even twitchy fingers on controls. Definitely not a smooth stable flight

 

[Merv]

Hard to tell from the pictures or video. Looks like a Kf airfoil with out any kind of spar.

Maybe the wings are flexing. Maybe try a thicker airfoil. Maybe round over the leading edge of the wing.

 

[Boiii]

Hard to tell from the pictures or video. Looks like a Kf airfoil with out any kind of spar.

Maybe the wings are flexing. Maybe try a thicker airfoil. Maybe round over the leading edge of the wing.

The wings should not flex. They are pretty stiff. I am gonna taper TE and LE after I find a design that works. Why are you recommending to use thicker airfoil. To make the wing stiffer?

 

[LitterBug]

Make sure your control rods, control horns, and servos are not flexing, especially the pushrods when pushing. With push rods that long, there can be quite a bit of flex. This can be difficult to diagnose, but rather easy to fix.

 

[L Edge]

Did you try any reflex? You might have to put a couple of degrees in.

 

[Boiii]

Make sure your control rods, control horns, and servos are not flexing, especially the pushrods when pushing. With push rods that long, there can be quite a bit of flex. This can be difficult to diagnose, but rather easy to fix.

Not saying that this is the problem here cause they are pulling to make the plane go up but what are the best types of fixis? Taping a bamboo scewer to the pushrod?

 

[Boiii]

Did you try any reflex? You might have to put a couple of degrees in.

Yes there is reflex. It may be a little bit more on one side.

 

[Boiii]

Video doesn't give much help, could be on edge of stall, local wind eddies, lousy CG placement, neighborhood radio interfering or even twitchy fingers on controls. Definitely not a smooth stable flight

Theoretically speaking if the Cg was off. Would not it make the plane pitch up? I did not use any down input in this flight

 

[L Edge]

Yes there is reflex. It may be a little bit more on one side.

Suggest you try it with the same amount and see what happens. You might cover the range of 1 to 3 degrees.

 

[Boiii]

Suggest you try it with the same amount and see what happens. You might cover the range of 1 to 3 degrees.

Just got back from another try. the reflex was about 5 degrees and it still would not want to stay in the air. there isn't thrust issue because it only weighs 220g.

 

[Boiii]

I am gonna post a DVR here soon. maybe it helps

 

[Boiii]

 

[L Edge]

Just got back from another try. the reflex was about 5 degrees and it still would not want to stay in the air. there isn't thrust issue because it only weighs 220g.

If there is not enough thrust, did you check to see if your prop is running the right direction?

 

[Boiii]

If there is not enough thrust, did you check to see if your prop is running the right direction?

yes. there is enough thrust. The plane wants to leave my hand so hard

 

[L Edge]

yes. there is enough thrust. The plane wants to leave my hand so hard

Make a video showing the wing and do sound so we can see the flight, not from nose. (make a head camera)

 

[Merv]

...To make the wing stiffer?

Yes, stiffer & thicker airfoil may add some stability. Somethimg is flexing, could be the wings, could be the pushrods, maybe something else.

Do I understand that you can't get any altitude? Or are you just trying to stay so low?

 

[joelspangler]

Does this have a dumb receiver or some sort of stabilized flight controller? An overturned flight stabilizing system can do that. If it's a dumb receiver, check that your linkages are tight enough to not wobble - the one pic seems to show a very large hole in the control horn.

 

[Boiii]

Yes, stiffer & thicker airfoil may add some stability. Somethimg is flexing, could be the wings, could be the pushrods, maybe something else.

Do I understand that you can't get any altitude? Or are you just trying to stay so low?

The plane just would not climb. Unfortunately, it is beyond repairable after the last flight (It is bent in weird angles).