HobbyKing.com New Products Flash Sale
Closed Thread
Thread Tools
Old Mar 30, 2012, 07:18 PM
Slow Flyer
Bombay's Avatar
Richmond, TX
Joined Apr 2008
3,234 Posts
Question
Aileron deflection question

Calling on the non-aerodynamically challenged...

As air moves over the surface of a wing and reaches an aileron, is it the air traveling over the top of the wing/aileron or the bottom of the wing/aileron that causes a change in attitude when the aileron is deflected?

The reason I ask is because one of the ailerons on one of my airfoiled depron parkflyers is attached slightly higher than the other at the hinge line. It is very minor...but I would like to know if it is more critical to have the top of the aileron match the wing or the bottom of the aileron. I suspect it is more critical to have the tops match up.

Bombay is offline Find More Posts by Bombay
Sign up now
to remove ads between posts
Old Mar 30, 2012, 09:22 PM
Shelter Kitty "Orange Death"
bartricky's Avatar
United States, FL, Monroe
Joined Jan 2008
3,146 Posts
Simple answer,

If the aileron goes up then the airflow over the top of the wing has more affect on it.

Don't think it is that critical but best if both ailerons are symmetrical.
bartricky is offline Find More Posts by bartricky
Old Mar 30, 2012, 09:49 PM
Registered User
United States, FL, The Villages
Joined Oct 2010
3,929 Posts
Make it neutral via mechanical adjustment! Loosen the connectors and get it right.

"If the aileron goes up then the airflow over the top of the wing has more affect on it."

Not that way. If the surface of the aileron goes "up", lift is spoiled. That wing will drop. If the aileron surface goes "down", there is MORE lift and that wing goes "up".

Get the surfaces level and correct. If one is out of whack, you'll have trim issues. No reason for you to chase trim when you know the surface are wrong. trim is for small changes, not the ones you can see.
Don
dkrhardy is offline Find More Posts by dkrhardy
Old Mar 30, 2012, 10:54 PM
Slow Flyer
Bombay's Avatar
Richmond, TX
Joined Apr 2008
3,234 Posts
Thanks. I will be mechanically adjusting them to get them as even as possible...and then sub-trim them, but the ailerons were slotted into the wing at slightly different levels, so I was wondering if top of wing alignment or bottom of the wing alignment is more crucial. I am assuming that alignment with the top, airfoiled surface is more crucial.
Bombay is offline Find More Posts by Bombay
Old Mar 31, 2012, 12:46 PM
An itch?. Scratch build.
eflightray's Avatar
South Wales U.K.
Joined Mar 2003
12,457 Posts
If you mean like the picture below, then unless it's excessive it probably wont have much affect.
You may need a little aileron trim to compensate.

If it really does look bad, then you really should replace the hinge method, (tape or individual hinges ?), and fix it.
eflightray is offline Find More Posts by eflightray
Old Mar 31, 2012, 01:28 PM
Slow Flyer
Bombay's Avatar
Richmond, TX
Joined Apr 2008
3,234 Posts
Quote:
If you mean like the picture below...
You got it. Thanks. I don't think it is a major issue, just trying to make the best of it. I'll align with the top and give it a go...and rip it apart as necessary.
Bombay is offline Find More Posts by Bombay
Old Apr 02, 2012, 10:45 AM
Registered User
Joined Mar 2010
1,333 Posts
Stick your hand out a car window at speed. Now angle it up and down and see how it reacts. That's how ALL plane control surfaces work. Including the prop.
rtbates is offline Find More Posts by rtbates
Old Apr 02, 2012, 11:22 AM
Slow Flyer
Bombay's Avatar
Richmond, TX
Joined Apr 2008
3,234 Posts
Quote:
Originally Posted by rtbates View Post
Stick your hand out a car window at speed. Now angle it up and down and see how it reacts. That's how ALL plane control surfaces work. Including the prop.
Yes, thank you, but this question was specifically about alignment/misalignment in the attachment of the control surfaces.

eflightray nailed it. Thanks for all the help and encouragement.
Bombay is offline Find More Posts by Bombay
Closed Thread


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Sold Great Planes AccuThrow Control Surface Deflection Meter Dr. J Aircraft - General - Miscellaneous (FS/W) 2 Mar 13, 2012 10:12 PM
Discussion dual aileron servos mixing question nitrosportman 3D / Fun Fly Fuel Planes 4 Mar 12, 2012 08:43 AM
Discussion Quick question: GCP servo aileron/elevator andrewho83 Micro Helis 2 Mar 08, 2012 12:34 PM
Discussion Aileron question molish Electric Plane Talk 8 Oct 06, 2011 08:05 PM
How V Tail setup and deflect? Magna Electric Sailplanes 11 Jul 28, 2005 03:30 PM