Ailerons!

[Legot]

I got the hobbypartz box, and let me tell you, THESE TIRES ARE HUGE! and I made a new rudder and elevator for bigger surfaces.

[Dillzio]

I made my ailerons and flaps last night, and covered them in profilm today. I've made them 50mm wide, and the flaps are 15cm, the ailerons are 25cm. I have a question about how tight a fit the ailerons should be in the wing.

After I profilmed mine, I think they shrunk a bit so they were a bit of a loose fit, and there was a gap of 2-3mm between the ailerons and the flaps. I've heard it's important to not let any air get from the top of the wing to the bottom, so you have to make sure everything's a good seal.

I made them tight again by supergluing a cut down popsicle stick to the wing on the inside edge of where the flaps sit. This has made the ailerons and flaps a nice tight fit, but they're a little too tight now and don't quite move freely. I can make the gap in the wing a fraction wider by lightly sanding it down a bit, but I was wondering about how important it is to have a perfect seal? It seems to me that it will be hard for the ailerons to move freely without at least some gap either side of them so they don't rub.

I've noticed I've got a bit of a gap between the ailerons and flaps on the corners too, where they're rounded in a bit. Do I need to plug these gaps, and if so, with what?


cheers

[ginginho]

Dillz,
You want them to move freely without any friction at the ends otherwise the servos will be straining. A small gap at the ends is inevitable, however you want to keep this as small as you can. The real problem with air leaking between the surfaces is along the hinge joint as this runs along a major portion of the area of the wing that gives lift, so if you haven't already, add a strip of profilm (or clear tape if it's mixed colours) along this line to seal it. You only have to do one side (top or bottom of the wing) but make sure that there is ample deflection of the surface in both directions when you apply the film. The easiest side to put it on is the opposite one to which you bevelled, so if it's bevelled towards the bottom, apply the film to the top, and vice versa, if that makes sense!

[Legot]

The gaps between all of my control surface edges are 1.5mm. Like ging said, it is best to keep as little friction as possible along the edges, and the hinge gap is the most important place to cover up.

It shouldn't be necessary to plug up these gaps, it shouldn't hurt the flight performance all that much. As long as the gaps for all are even on both sides to prevent any unwanted roll.
again, it's no big deal and should be fine.

[akbushpilot]

Apr 30, 2010 11:48:23 GMT 1 helikiwi said:

looking good - here's some pictures of what I did.
I have 2 servos for ailerons and 1 flaps
I programed the ailerons to come down a little bit with the flaps - like a R/STOL kit on full scale cessnas - it slowed down to a crawl but dropped a wing easily, and the rudder had very little authority at that slow speed to pick up the wing - so now I have the ailerons raise a little bit with full flap only - no wing drop and I can come in steep

What TX are you using???
Would I be able to do this with a DX8, or should I wait to see, before I buy it

[leisureshoot]

Oct 26, 2010 23:56:22 GMT 1 akbushpilot said:

Apr 30, 2010 11:48:23 GMT 1 helikiwi said:

looking good - here's some pictures of what I did.
I have 2 servos for ailerons and 1 flaps
I programed the ailerons to come down a little bit with the flaps - like a R/STOL kit on full scale cessnas - it slowed down to a crawl but dropped a wing easily, and the rudder had very little authority at that slow speed to pick up the wing - so now I have the ailerons raise a little bit with full flap only - no wing drop and I can come in steep

What TX are you using???
Would I be able to do this with a DX8, or should I wait to see, before I buy it

I think you can get that mix on even a DX6i, can't you?

[leisureshoot]

heli kiwi, can you (or anyone else) explain what is occurring in the scenario you described?

You stated that having the equivalent of a "flap" across the entire wing causes a wing to drop easily, but the solution is to raise both ailerons, slightly? (so in this instance, they are like an air brake?)

Why is there a difference whether they go up or down? I assume it has to do with going the opposite direction of the flaps, so they are holding the wing more steady, vertically, as opposed to all surfaces pointing down, which makes both wings want to rise up?

[charliebrown]

Up: Loss of lift, increased drag (airbrakes).
Down: Lowered stall speed, increased lift, increased drag (flaps).

[akbushpilot]

thanks leisureshoot.

on an R/STOL kit dont the flaps go down 2 notches, and on the third notch the ailerons go down too, then on the fourth notch down the ailerons go back up?

If so then right before touchdown that last notch would eliminate a tip stall.

[charliebrown]

That's correct, ak. You're effectively lowering the angle of attack of the outside part of the wing when you raise the aileron, and the AOA determines when it stalls (very simplified).

Edit: At least IRL, you want the inner part of the wing to stall first so you don't lose the effectiveness of the ailerons.

Edit 2: Btw, do you fly in real life, ak? If so I apologize for explaining what you already know.

[akbushpilot]

I am only 14, but I am training. I only have an hour in a 206, and an unofficial 15 minutes in a 180 (both Cessna). Where I used to live was a small town only accessed by plane, and there was a lot of bush flying. Many people I know are pilots so I had a bank of knowledge on hand.
Not anymore . I know live in the horrible metropolis of Anchorage.

But I did not know that, so thank you.

[charliebrown]

You're welcome.
And it's all about who you know, not so much where you live (at least that's what I tell myself).

[akbushpilot]

I had freedom there. We could ride fourwheelers, dirtbikes, and snowmachines anywhere we needed to go. and me and my friends went duck hunting everyday after school in spring and fall. it is as my mom says "a man's world"

[charliebrown]

Good point. I take back my previous statement.

[akbushpilot]

lol