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-   -   Aileron Setup question (http://www.Wattflyer.com/forums/showthread.php?t=73875)

Davethebluessinger 06-11-2014 08:01 PM

Aileron Setup question
 
Hi Guys, hope someone can explain what I need to do here!
Heres my question!
On a wing with a cambered top and flat bottom I would initially set my aileron neutral with a straight edge so the lower wing surface and lower aileron surface formed a dead straight line

How do I set up the neutral position on a symmetrical wing with a very thick leading edge? Should I just make it look even top and bottom?

Just donít want to plant a brand new plane on its maiden!!!


Thanks

Dave

fhhuber 06-11-2014 08:26 PM

You aim for a straight line from LE to centerline of the hinge line to center line of the TE. Its very difficult to get it exact so expect slight trim adjustments to be needed.

If you are off you want to be off with the ailerons very slightly UP not down as downward deflected ailerons can lead to instability when you slow down to land.

I often put the ailerons into "flaperon" programming, assigned to a dial, with flap function at 10% or less so I can trim in the ailerons in flight.

solentlife 06-11-2014 08:26 PM

Usually I do it by eyeball .. the eye is remarkably accurate in seeing an out of align item ...

But there are ways to do it ..

A straight edge held along the Centreline so the Leading edge centre, aileron front edge centre and aileron trailing edge centres all form a straight line...

Second way - and this is trusting that you hold the ruler edge similar areas top and then bottom. A symet wng with correct aileron form ... the aileron should continue the symet form to it's trailing edge as if it was a fixed rib. So putting the ruler straight edge along the rear top section of the wing should show whether the aileron is UP or DOWN ... then do same to the rear bottom section ... you should see equal results.

There are some wings and tailplanes that can be difficult to determine centre line - my Edge 540 is like that ... by eyeball - the elevators have a slight up to them. Put a straight edge and you see the 1 - 2mm error.

BUT final word ... In fact aligning the ailerons to wing is not the most important factor. The most important is having BOTH ailerons the same right and left. This is easy to do with a ruler and a flat table. Block up the model so wing tips are exact same height of table. Now measure the ailerons trailing edge height of the table. Make both the same. Even if they are now slightly out of alignment with wing - they both make the same 'lift coefficient' ... a starting point for trimming.

So my advice ... set up by eyeball reasonably straight ......... then do the table bit of getting them same. Go fly, trim and enjoy.

Nigel

xmech2k 06-11-2014 08:37 PM

I'm no expert, but I just always keep the trailing edges aligned.

kyleservicetech 06-11-2014 08:47 PM

Quote:

Originally Posted by Davethebluessinger (Post 950304)
Hi Guys, hope someone can explain what I need to do here!
Heres my question!
On a wing with a cambered top and flat bottom I would initially set my aileron neutral with a straight edge so the lower wing surface and lower aileron surface formed a dead straight line

How do I set up the neutral position on a symmetrical wing with a very thick leading edge? Should I just make it look even top and bottom?

Just donít want to plant a brand new plane on its maiden!!!


Thanks

Dave

If you have one of those newfangled cellphones, check out the Clinometer app. This is a very nice level that measures in degrees. Just check both ailerons with it.

kyleservicetech 06-11-2014 08:51 PM

Quote:

Originally Posted by fhhuber (Post 950306)
You aim for a straight line from LE to centerline of the hinge line to center line of the TE. Its very difficult to get it exact so expect slight trim adjustments to be needed.

If you are off you want to be off with the ailerons very slightly UP not down as downward deflected ailerons can lead to instability when you slow down to land.

I often put the ailerons into "flaperon" programming, assigned to a dial, with flap function at 10% or less so I can trim in the ailerons in flight.

Yeah I've tried those flapperons in several of my models. Could just be me but never much cared for them. Imho, true flaps work better than flapperons.

Davethebluessinger 06-11-2014 10:03 PM

Thank You Folks for all of your responses, I'll set her up tomorrow!:D

solentlife 06-11-2014 10:40 PM

Quote:

Originally Posted by Davethebluessinger (Post 950323)
Thank You Folks for all of your responses, I'll set her up tomorrow!:D

Just bear in mind - that the ailerons should be level with EACH OTHER ... that is the main item to ensure.

Once flown and trimmed - you often find one slightly raised compared to other .. quite often right one slightly up a mm or so ... but that's based on trim once flown.

Nigel

fhhuber 06-11-2014 11:59 PM

I use the flaperon for trimming aileron center, not really for flap function.

You might be surprised how much effect just a little up or down on both ailerons can affect the way a plane flys. Get everything trimmed in well and the airplane will be easier to handle. When I was flying Pattern I learned to dial in every surface as exactly as possible.

solentlife 06-12-2014 09:20 AM

Quote:

Originally Posted by fhhuber (Post 950327)
I use the flaperon for trimming aileron center, not really for flap function.

You might be surprised how much effect just a little up or down on both ailerons can affect the way a plane flys. Get everything trimmed in well and the airplane will be easier to handle. When I was flying Pattern I learned to dial in every surface as exactly as possible.

Flaperons are accepted as a poor substitute for separate flaps, because they extend out usually for near enough whole span of wing. Use of flaps then increases possibility of tip problems.
They are useful though ... not only as flaps (in moderation of course !) and as fhuber says - to trim aileron centre.
The other of course is the opposite use - Spoilerons .... now this actually can be better use of them as the tip problems are reduced when deployed. You get a higher sink rate assisting with landing approach particularly on smooth fast models.

My Edge 540 racer is far better at landing with only a few mm deflection up as spoilerons than without. Flaperons tended to make that tapered wing more prone to dropping a wing and / or floating on.

Anyway - OP asked about centreing ailerons - which has been answered ... so lets wish him luck.

Nigel

mclarkson 06-13-2014 11:05 PM

Quote:

Originally Posted by solentlife (Post 950351)
Flaperons are accepted as a poor substitute for separate flaps, because they extend out usually for near enough whole span of wing. Use of flaps then increases possibility of tip problems.

Funny you should mention that. On a new build of mine, I've been playing with flaperons. It's a plane especially inimical to flaperons, as the ailerons themselves are only on the very tips of the wings.

It does slow it down, but handling becomes much more iffy, with severe 'tip problems.'

solentlife 06-14-2014 07:37 AM

Given that full span ailerons are actually overlong ... and the centre sections are having very little ROLL effect ... the main effect is from the outer sections .... think of the lever moments out there ...

I like to separate them by cutting the inner section away and hingeing separately. Even on a reasonable size park model, you do not need big servos for flaps. On my Cessna - I use a cheap Turnigy 4gr servo for each flap and never had any trouble.

This way - you get real flaps, no tipstall problems, ailerons still fully effective ...

Nigel

mclarkson 06-14-2014 07:57 AM

Absolutely. This model was never intended to have flaps. I was just fartin' around. :D

solentlife 06-14-2014 08:21 AM

If people didn't experiment - things would never progress ...

Nigel


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