Help! Deflection of control surfaces not even on both sides of the elevator in FT Flyer

[Karthik1130]

1)Any way on how to make the twisted foamboard flat against the ground?
2) Any way to strengthen the wing root section in wing to withstand heavy wind speed? the wing literally folds itself in the center at good wind speed and crashes.
If available can anyone show some examples.

 

[Foamforce]

Unwarping foam has been hit &miss for me. The best I’ve been able to do is to set mine on a table, propped up on books so that it’s twisted back past straight (so bent in the opposite direction) and then leave it there overnight.

I think your problem with the wings breaking is the foam that you’re using. It looks brittle and doesn’t have paper to reinforce it. Maybe you could try attaching paper using a spray adhesive. Then you’d have something more like the Adam’s Readi-Board that the FF planes are designed for. Otherwise, you’ll need better spars. Check out what people on RC Groups have done with Depron. It looks similar to what you’re using. They use thin strips of carbon fiber and insert it into slots cut into the wings.

 

[Merv]

1)Any way on how to make the twisted foamboard flat against the ground?
2) Any way to strengthen the wing root section in wing to withstand heavy wind speed? the wing literally folds itself in the center at good wind speed and crashes....

You might consider a Kf2 wing, Here is an article to explain https://www.flitetest.com/articles/kfm-wings-a-basic-explanation

The extra layer of foam will help flatten the foam & add some strength. I have had good results gluing 2 sheets of foam together, I prefer white glue for this application. Arrange the foam so the bows are in the opposite direction. Glue them together & clamp them to a flat surface to dry. When dry, they will hold each other straight

 

[Karthik1130]

A successful maiden flight of FT Flyer. it flew for like 7 minutes or so until I lost the signal and the plane got stuck in the tree.
The wings centre section were strengthened using Fibreglass tape, and it helped in withstanding the wind speed.

Took to a high altitude and did 360° left and right circles and also loops.

Thanks a lot guys.

 

[Karthik1130]

Today,took another FT Flyer for maiden. It was a catastrophe. The plane just kept on pitching up and looping in the same location and also sometimes maintaining high alpha position,irrespective of me trying to turn it left or right or pitching the elevator down.
The plane didn't went in a straight line., and it was doing just high alpha and loops in the same location.
After few minutes, the wing broken down in mid-air even after reinforcement with fibreglass tape ,and crashed into the ground.

I couldn't able to find the plane from the thick dense bushes, where it fell down . Tomorrow morning planning a rescue search.

I don't know what could be the issue of plane constantly looping. could anyone help please.

 

[quorneng]

It sounds to me as if you have the CG much too far back.
How far back from the wing root leading edge does it balance at the moment?
With such a broad chord wing and short tail plane moment it will be very sensitive to the position of the CG.

 

[Karthik1130]

went to the crash site and searched in the dense bushes, but couldn't find it. lost the plane along with receiver, motor,esc, servos,low voltage lipo battery alarm.

 

[quorneng]

Bad luck!
I also lost a plane in dense bushes. Still annoys even to this day.

 

[Foamforce]

went to the crash site and searched in the dense bushes, but couldn't find it. lost the plane along with receiver, motor,esc, servos,low voltage lipo battery alarm.

Keep up the search. You’d be surprised how far off you are when your guess where a plane came down. My son lost control of his plane and I watched it go down in the distance so I remembered the trees that it landed near and walked straight toward it. I walked around for an hour before greatly expanding my search radius. I found out not long after, about 800 feet from where I thought it had come down! Once I got within a couple hundred feet, it was easy to see, but I had spent all my time carefully scouring a small area. The lesson is to look less carefully but cover a lot more ground. I hope you find it eventually!

 

[L Edge]

went to the crash site and searched in the dense bushes, but couldn't find it. lost the plane along with receiver, motor,esc, servos,low voltage lipo battery alarm.

When you lose an airplane, always bring your radio along. If by chance the battery may be connected, if you stop and listen and move both the controls of your radio, you might by able to locate it by the sound of the servo moving or even motor wine/prop slapping .
More than once at a club field, we located it. And as usual, the lipo battery will drain within 24 hours.

 

[Karthik1130]

Hi all, I will again try to do rescue search, but in the mean time I have reinforced the entire wing with fibreglass tape to avoid break in mid-air. It took a good amount of time. Any other ideas are welcome.

Regarding the alignment bamboo barbeque dowel to be pierced in the front of the wing, I find it difficult as when I drill the foam with the dowel it comes out through another side of foam midway.How to exactly drill it in the center of wing thickness along the entire drill path?

 

[Karthik1130]

It sounds to me as if you have the CG much too far back.
How far back from the wing root leading edge does it balance at the moment?
With such a broad chord wing and short tail plane moment it will be very sensitive to the position of the CG.

You were right the CG was off,to the back. I didn't do CG pre check before flight.

 

[Karthik1130]

Hi all, I will again try to do rescue search, but in the mean time I have reinforced the entire wing with fibreglass tape to avoid break in mid-air. It took a good amount of time. Any other ideas are welcome.

Regarding the alignment bamboo barbeque dowel to be pierced in the front of the wing, I find it difficult as when I drill the foam with the dowel it comes out through another side of foam midway.How to exactly drill it in the center of wing thickness along the entire drill path?

it was a excellent maiden flight. The fibreglass tape ensured the wing doesnt break in mid-air. It was a successful five times handlaunch flight at 15km/h constant wind with each lasting 35secs. The landing was successful in 2 times.

The only issue was the wing took a lot of bend in high speed wind and the dihedral angle became high and unequal between the left and right wing. Thus the plane spiralled to the ground.

I would like to know your ideas on how to give dihedral support at the top side of the wing and thus ensuring the wing doesnt buckle up in high speed wind.

Please help!

 

[Karthik1130]

I was looking about wing dihedral bracing in all high wing beginner rc planes. So had implemented the same here in FT Flyer.

Cut a slot in both left and right wing, and glue a bamboo dowel over the top of wing and passed a rubber band through the bamboo into the slot and passing below the fuselage and to the other wing bottom side and connecting to the bamboo skewer used for attaching the powerpod to the airframe.

This was don't to avoid wing buckling unser high wind speed. I will test it and post the update.

 

[quorneng]

Not exactly an aerodynamic solution. It may cause so much extra drag that the wing won't bend simply because you will not be able to reach "high speed".
Why not simply glue a single piece dowel right across the wing's underside. It does not have to go from tip to tip just half way out would add stiffness to the area that is under maximum bending.

 

[Karthik1130]

Not exactly an aerodynamic solution. It may cause so much extra drag that the wing won't bend simply because you will not be able to reach "high speed".
Why not simply glue a single piece dowel right across the wing's underside. It does not have to go from tip to tip just half way out would add stiffness to the area that is under maximum bending.

thanks a lot, I will try this in my next build.in some other models the dowel is embedded inside the foam wing. why it's not placed under the wing?
What's the difference between the two types of dowel placement in wing?

 

[L Edge]

Another way to solve the high speed folding of the wing is to get 30 min epoxy and fiberglass cloth from the LHS. Then say take a strip 4"(2" on each dihedral half wing) wide and epoxy all the way around including the ends and overlap the end. Go to U-Tube to watch how to do it.

 

[quorneng]

A dowel under the wing disturbs the airflow so alters the way a wing will behave. Not an ideal solution.
Much better to embed a dowel or carbon fibre rod in the wing if possible so it has no effect on the wing's aerodynamics.

To create a wing that is stiff, strong and as light as possible as well as being aerodynamically efficient can require quite complex internal structures. You will find there is much to learn.

 

[Karthik1130]

The pushrods are bending and binding the servo and causing unequal movement of the control surfaces. Even using that ziplock, doesn't straighten the movement of pushrod instead it binds the servo.

Is there any good solution for this?

 

[Karthik1130]

Hello all, what is meant by bleed off power in wingover aerobatic manoeuvre ?