Flap/wing/aileron line up question. Help.  
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Flap/wing/aileron line up question. Help. - 4/16/2008 10:39:29 PM   
Pete737



Posts: 328
Joined: 5/14/2006
From: Providence, RI, USA
Status: offline 		ok. My hanger 9 p47 150 is almost ready to go today I noticed there is a slight deviation in the left and right wing flap aileron line up. I lined them up per the instructions but I think I payed too much attention to the wing and control surfaces lining up from the top view of the wing as the instruction said. From a rear veiw the left flap is about an 1/8" lower than the aileraon in neutral than the right. I can find some sort of equilibrium by trimming but since the flap can no longer be moved I can't get the wing to be perfectly level when viewed from behind.

Just curious as to what your thoughts are.

Thanks!!!!!

Pete.
       Post #: 1

RE: Flap/wing/aileron line up question. Help. - 4/17/2008 2:17:24 AM   
seanreit



Posts: 6454
Joined: 4/17/2002
From: Cedar Park, TX, USA
Status: offline 		I'm not familiar with that airplane, so a picture would help on a fix. However, rest assured, in flight, this is only going to end up with you carrying some trim.

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(in reply to Pete737)
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RE: Flap/wing/aileron line up question. Help. - 4/17/2008 8:46:27 PM   
BMatthews



Posts: 8777
Joined: 10/4/2002
From: Burnaby, BC, CANADA
Status: offline 		You need to fix all that. The flaps and ailerons alter the camber and incidence angles of the wing segments where the parts are located. You want your wing to be "flat" along the whole length. The trailing edges need to line up or you'll find the model rolls from the reaction to the surfaces. Close enough isn't in this case. It's got to be perfect enough that you can't see the differences by eye.


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Bruce-
Proudly wasting balsa since 1965.

Free Flighters go that extra mile........

(in reply to seanreit)
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RE: Flap/wing/aileron line up question. Help. - 4/17/2008 9:55:19 PM   
da Rock



Posts: 6096
Joined: 10/11/2005
From: western, NC, USA
Status: offline 		I don't know if the 150 P47 is hinged with CA hinges or not. But if it is, it's easier to fix that problem by cutting all of them. Trim the stubs flat. Then place hinges in between. There's always plenty of room. And this time you've got lots of incentive to align the slots.

I can't remember an ARF in the last two years that didn't have pre-cut hinge slots that didn't need to be straightened or moved up/down. It appears to be acceptable to the mfg's for their workers to do that job far less than perfect.

(in reply to BMatthews)
       Post #: 4

RE: Flap/wing/aileron line up question. Help. - 4/17/2008 10:04:07 PM   
Pete737



Posts: 328
Joined: 5/14/2006
From: Providence, RI, USA
Status: offline 		I cant fix it. It is the flap panel. The hinges are glued. I can't de bond them either, If I cut them I will have stubs in the wing and flap. The ailerons are both lined up with the outboard TE and I can see the also lined up with the inboard TE but the left flap surface is slightly off when controls are neutral. I guess i'm going to have to fly with some trim.

Pete

(in reply to da Rock)
       Post #: 5

RE: Flap/wing/aileron line up question. Help. - 4/17/2008 11:36:45 PM   
gboulton



Posts: 1862
Joined: 5/28/2005
From: La Vergne, TN, USA
Status: offline
quote:

ORIGINAL: Pete737

I cant fix it. It is the flap panel. The hinges are glued. I can't de bond them either, If I cut them I will have stubs in the wing and flap. The ailerons are both lined up with the outboard TE and I can see the also lined up with the inboard TE but the left flap surface is slightly off when controls are neutral. I guess i'm going to have to fly with some trim.

Pete


I'm not quite getting why you can't fix this. (And, for the record, I agree with BMatthews...this needs to be fixed...more in a minute)

You say the hinges are glued. Fine. Cut them. But then you say you'll have "stubs" in the wings and flap. So? Why can't you just sand those stubs down flat with the flap LE and wing TE, and then remount the hinges elsewhere? As da Rock said...there's going to be plenty of room on that airplane to do that. If the hinges are "backed" by blocks inside the structure, then it's even easier...just cut out (if they're flat CA type hinges) or drill (if they're "peg" hinges) the old hinges away, and either fill in the slot/hole (hinge pockets would work well here if they're the peg type) or use larger hinges.

In short, there's probably a dozen alternatives here. Without having pictures, it's impossible to say which would be most advisable.

As for deciding to 'fly with some trim", be aware that what you've done is changed the AOA of ONE of the wings. This will induce both a roll AND yaw problem....the effect of which will vary with airspeed. In short, you're likely to find an airplane that "won't trim"...that is, it'll be "hands off" at one throttle setting, but "out of trim' at another...not an enjoyable situation with ANY airplane, but even more of a handful with a big warbird.

Now, in this case, your 1/8" PROBABLY isn't enough to cause many problems for casual flying...but it's really one of those "it'd be a quick and easy fix, why not get it right?" things.

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(in reply to Pete737)
       Post #: 6

RE: Flap/wing/aileron line up question. Help. - 4/18/2008 1:12:09 AM   
Pete737



Posts: 328
Joined: 5/14/2006
From: Providence, RI, USA
Status: offline 		Ok, So I brought my wings to my LHS and showed Andy. We played around with the alignments. Stole a bit from the aileron/tip and a little from the flap/aileron on the other side. He says it's a good compromise and it's not worth starting over. Worst case scenario is a bit more trimmin g than usual. Anyway the culprit was a deviation between the 2 TE flap sections, One was curved slightly while the other was not.

Heres the deal. Tommorrow I pick up my G-26ei, Prop and spinner. If I can fly this beast with fixed gear (until my retract servos come in) I can maiden on saturday. What do you think???

Pete

(in reply to gboulton)
       Post #: 7

RE: Flap/wing/aileron line up question. Help. - 4/18/2008 2:28:25 AM   
BMatthews



Posts: 8777
Joined: 10/4/2002
From: Burnaby, BC, CANADA
Status: offline 		Without seeing the degree of the issue I'll have to defer to the shop owner.

There will be effects though. It'll do things differently at one speed vs another.


_____________________________

Bruce-
Proudly wasting balsa since 1965.

Free Flighters go that extra mile........

(in reply to Pete737)
       Post #: 8

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