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Author Topic: Trim Tab  (Read 1727 times)

Offline Paul Allen

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Trim Tab
« on: January 31, 2009, 09:40:59 PM »
Guy's
       Need to fit a trim tab to a Sig Banshee to correct a low outboard wing upright
and high outboard wing up inverted,I do not want to risk breaking the horn wire out of the flaps
by tweaking it,so how to attach a trim tab or a wart,(is this the correct term for it).
Thanks
Paul Allen  H^^

Online Brett Buck

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Re: Trim Tab
« Reply #1 on: January 31, 2009, 09:49:08 PM »
Guy's
       Need to fit a trim tab to a Sig Banshee to correct a low outboard wing upright
and high outboard wing up inverted,I do not want to risk breaking the horn wire out of the flaps
by tweaking it,so how to attach a trim tab or a wart,(is this the correct term for it).
Thanks
Paul Allen  H^^


   A wart is different from a trim tab - typically "wart" is usually reserved to a part attached to the flap, straight with the rest of it, to add area. Trim tabs are typically put on to correct warps.

     If you are concerned about tweaking the flaps, use plywood squares to back up the flaps where the wire goes through. Alternately, de-warp the wing using a heat gun or the boiling water and towels trick.

    Brett

Offline Glenn (Gravitywell) Reach

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Re: Trim Tab
« Reply #2 on: January 31, 2009, 09:57:01 PM »
Hot water and towels trick?  I need to hear more about that one please. H^^
Glenn Reach
Westlock, Alberta
gravitywell2011 @ gmail . com

Online Paul Taylor

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Re: Trim Tab
« Reply #3 on: January 31, 2009, 10:17:06 PM »
I have not done it, but I have heard that folks have glued plastic tabs the kind used for file folds as trim tabs.

Keep it Simple.

Just a thought.
Paul
AMA 842917

As my coach and mentor Jim Lynch use to say every time we flew together - “We are making memories

Offline Howard Rush

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Re: Trim Tab
« Reply #4 on: January 31, 2009, 11:36:16 PM »
Countering a wing warp with a trim tab is kinda like letting the air out of your car's left front tire when the right front tire goes flat.   I did a search on the Banshee on the Web.  It looks like the LE isn't sheeted, so the structure can be dewarped easily.  Look at the wing from behind.  Hold it so the TE is centered on the wing thickness.  You should be able to see the warp. 

If the airplane is covered with plastic, heat the covering with a heat gun or iron wile you bend the wing opposite the warp.  Keep holding in the twist until the wing cools.  If it's covered with paper or silk, pour boiling water on the wing while you bend the wing opposite the warp.  Keep holding in the twist until the wing cools.  The purpose of the towel is to mop up the water.  You don't need to put it on the airplane.   

You can dewarp flaps using the same methods.  If your problem is misaligned flaps, rather than warped flaps or wings, you should tweak the flap control horn.  You can put pieces of plywood on either side of each flap where the horn arm is and usually bend the horn without hurting the flaps, as Brett says.   

Standard field equipment for combat guys, who are always trimming new airplanes (combat planes don't last), is a Monokote iron and generator or inverter for dewarping. 
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Making combat and stunt great again

Online Brett Buck

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Re: Trim Tab
« Reply #5 on: January 31, 2009, 11:39:58 PM »
Hot water and towels trick?  I need to hear more about that one please. H^^

    If you have a stunt wing covered with silkspan and painted, its not going to respond to steam from a teapot. So you take a big towel and wrap it around the thing you want to de-warp. Get someone you trust to pour boiling water onto the towel, soaking it , while you twist against the warp. You will feel it "give" almost immediately.  Hold it twisted straight for 20-30 seconds, remove towel, and keep holding against the twist until it cools down. It will stay in the shape you twisted it.

     Brett

Online Brett Buck

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Re: Trim Tab
« Reply #6 on: January 31, 2009, 11:42:02 PM »
If the airplane is covered with plastic, heat the covering with a heat gun or iron wile you bend the wing opposite the warp.  Keep holding in the twist until the wing cools.  If it's covered with paper or silk, pour boiling water on the wing while you bend the wing opposite the warp.  Keep holding in the twist until the wing cools.  The purpose of the towel is to mop up the water.  You don't need to put it on the airplane.   

   I alway do, it keeps the water on the wing long enough to steam the insides. Might not be necessary for a Banshee wing, but for something like a Nobler wing, pouring it on the outside and letting it just run off doesn't usually cut it.

    Brett

Offline Howard Rush

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Re: Trim Tab
« Reply #7 on: January 31, 2009, 11:47:30 PM »
"Get someone you trust to pour boiling water..."

I do the pouring.  It's easier to find somebody I trust to react the twist than it is to find somebody I trust to pour the water.
The Jive Combat Team
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Offline John Stiles

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Re: Trim Tab
« Reply #8 on: February 01, 2009, 01:27:48 AM »
Getting somebody tyou trust to pour boiling water on your wing, is like trying to find someone you trust to take your ole lady out on a date! LL~
John Stiles             Tulip, Ar.

Offline don Burke

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Re: Trim Tab
« Reply #9 on: February 01, 2009, 09:43:36 AM »
If you have a large wall mirror use it to check for warps and corrections.  Hold the airplane at eye level so you can see the TE in the mirror.  Makes it real easy to see the misalignment.  The hot water seems like a good idea, as long as you do trust someone!
don Burke AMA 843
Menifee, CA

Offline Paul Allen

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Re: Trim Tab
« Reply #10 on: February 01, 2009, 02:13:34 PM »
Thanks for the advice,I did the flap tweak with the ply plates,only
required a small deflection,I seem to remember a photo somewhere
showing some tapered trailing  edge stock glued under the trailing edge
of a model to correct a misalignment.


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