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  #11  
Old 12-03-2018, 05:18 PM
Steve Melton's Avatar
Steve Melton Steve Melton is offline
 
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Location: Cincinnati, OH
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put the flaps in the up position. select a rivet on top of the wing and measure with a scale to the trailing edge of the flap. set the opposite side to same measurement. flaps should be set to the wing not to anything else. you might think, it's not possible to measure this way, but it is.
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Last edited by Steve Melton : 12-03-2018 at 06:04 PM.
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  #12  
Old 12-03-2018, 10:22 PM
control control is offline
 
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Be careful, we have been told several times by Vans now that the 14 is somewhat different than the other RVs when it comes to alignment
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  #13  
Old 12-05-2018, 05:27 PM
johnmcdonnell johnmcdonnell is offline
 
Join Date: Apr 2008
Location: Yardley, PA
Posts: 16
Default Wedge is an easy fix

Guys,

Please don't flame me, you more technical guys, about a "proper" fix
Just trying to help a fellow RV pilot with a cheap, easy, and reversible solution.

A very easy fix for my heavy wing which could not be trimmed out with the manual trim, was a small piece of trailing edge Balsa wood affixed to the underside of the aileron of the LIGHT wing. That location may seem counter intuitive. But that's the way trim tabs work and the wedge is in effect, a trim tab.

We tried various lengths with both tanks full and fuel load balanced until it flew perfectly level with the manual trim lever and stick centered.

About a 6" length fixed the heavy wing for us in our RV4. There was no detectable change in speed, but the plane was noticeably more pleasant to fly.

Held in place with white Gorilla tape and is virtually invisible being on the underside of the aileron and the white tape matching our white aileron.
(Gorilla tape does come in a variety of colors and seems strong enough to survive at least mach 2 speeds)

The biggest issue was finding a place to buy the trailing edge balsa wood. Once I found a vendor I had to buy way more than I needed (i.e. several 3 FOOT lengths) but it was cheap. If you PM me with your address and contact info I would be more than happy to send you a three foot length.

FYI My RV4 is a plane which I did not build. I bought it last March. We suspect the heavy wing is the result of some hanger rash where the previous owner dented an aileron on a hanger door. The intent is to re-skin the damaged aileron over the nasty flying weather months of January/February in this part of the world. But for now this was a great solution.
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  #14  
Old 12-05-2018, 08:31 PM
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Plummit Plummit is offline
 
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So where on the aileron do you tape the wedge? Towards the root or tip, front or rear (trailing edge).

-Marc


Quote:
Originally Posted by johnmcdonnell View Post
Guys,

Please don't flame me, you more technical guys, about a "proper" fix
Just trying to help a fellow RV pilot with a cheap, easy, and reversible solution.

A very easy fix for my heavy wing which could not be trimmed out with the manual trim, was a small piece of trailing edge Balsa wood affixed to the underside of the aileron of the LIGHT wing. That location may seem counter intuitive. But that's the way trim tabs work and the wedge is in effect, a trim tab.come in a variety of colors and seems strong enough to survive at least mach 2 speeds)
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  #15  
Old 12-06-2018, 04:43 AM
johnmcdonnell johnmcdonnell is offline
 
Join Date: Apr 2008
Location: Yardley, PA
Posts: 16
Default Positioning the Wedge

Quote:
Originally Posted by Plummit View Post
So where on the aileron do you tape the wedge? Towards the root or tip, front or rear (trailing edge).

-Marc
Marc,

I don't think the positioning laterally (towards root or tip) matters much since the purpose is to move the entire aileron. However I chose to put the wedge laterally toward the center of the trailing edge of the aileron on the bottom of the light wing, straddling one of the stiffeners of the aileron.

Orientation front to back the wedge is positioned with the thick portion of the wedge aligned with the underside of trailing edge of the aileron.


As previously mentioned, putting the wedge on the underside of the light wing may seem counter-intuitive (at least it was to me initially), but this is indeed the correct position. i.e. For a heavy left wing causing the plane to bank left, the wedge goes on the underside of the right wing aileron.

In taping the wedge to the aileron I chose to tape over the entire wedge, as opposed to using double sided tape or permanently mounting it with epoxy or silicone seal as other posters have mentioned in other threads.

i.e. The tape starts about a quarter inch in front of the thin portion of the wedge on the underside of the aileron to make a smooth transition from the aileron to the wedge. The tape then extends over the thick part of the wedge terminating on the top side of the aileron with about a quarter inch of tape showing on the top edge of the aileron. Thus the entire balsa wedge is enclosed in tape and protected from the elements.

Is this clear? I'd take a picture but as I mentioned in a previous post the repair is virtually invisible with the white Gorilla tape closely matching the white paint of the aileron.
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  #16  
Old 12-06-2018, 05:12 AM
bobnoffs bobnoffs is offline
 
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i have used a wedge on a different type of plane to trim it and i put the wedge over an underlying structural part of the aileron. it is exerting force.
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  #17  
Old 12-06-2018, 06:03 AM
Tom Martin Tom Martin is offline
 
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Location: Ontario, Canada
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Bob Turner laid this out in post #2. Add point number five, that the elevator has to be set in the neutral position.
Before you try wedges etc, raise the flaps up all the way by adjusting the linkage. Do the ailerons line up with the flaps? If not then adjust them. Do the wingtips line up with the ailerons? I suspect you will find one, or both wing tips are not lined up.
Some have used the jig and it works fine, but it did not in your case. The jig is definitely used to set the aileron bell crank in the correct location

Please take the time to try this method
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  #18  
Old 12-06-2018, 06:33 AM
BillL BillL is offline
 
Join Date: Sep 2007
Location: Central IL
Posts: 4,929
Default Wedges, tabs, and straws.

Excellent help here and I only have two heavy wings repaired so a novice. In my 7 journey, I read about the straw trick. This is just for debugging and interest. The post said to use a coffee stirring straw, plastic, start with 4" long. Tape it parallel to the TE back about 1/2-3/4" from the edge. Use some thin tape, but masking works just as well. Put it under the light aileron. Middle- end, it does not matter, but I liked the middle. It worked for rudder yaw and aileron/heavy wing debugging to ensure the plane flew straight with it installed. It was pretty effective and easier than making a wedge or tab for experimentation.

It works like a wicker bill. A Gurney flap. Look at NASA's evaluation of what Dan Gurney discovered while racing if you want to know the science behind it.

Can anyone post a picture or email to me a screen capture of the new hinge design??

So who cares about tabs, wedges and straws? Why?? I found 3 kts (or at least I think I did ) with the heavy wing fix on my 7. If that does not matter, then just tab-wedge-straw it.
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Last edited by BillL : 12-06-2018 at 06:39 AM.
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  #19  
Old 12-06-2018, 08:52 AM
Bavafa Bavafa is offline
 
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Location: Sacramento, CA
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Quote:
Originally Posted by Tom Martin View Post
Bob Turner laid this out in post #2. Add point number five, that the elevator has to be set in the neutral position.
Before you try wedges etc, raise the flaps up all the way by adjusting the linkage. Do the ailerons line up with the flaps? If not then adjust them. Do the wingtips line up with the ailerons? I suspect you will find one, or both wing tips are not lined up.
Some have used the jig and it works fine, but it did not in your case. The jig is definitely used to set the aileron bell crank in the correct location

Please take the time to try this method
As mentioned in the post, the alignment has been checked and rechecked but not in relation to the elevator and I am planning on checking that this weekend. However, please help me understand this that if the elevator was to cause deflection of the ailerons, wouldn't than you expect the plane have a wing heavy in climb or decent if it was rigged correctly in neutral?
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  #20  
Old 12-06-2018, 10:55 AM
rvbuilder2002 rvbuilder2002 is offline
 
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If neither the flaps or ailerons have any twist in them, and everything is rigged correctly, the deflection that occurs on the ailerons when the elevator is moved, happens equally on both sides. It occurs because the control column that each aileron push/pull tube is attached to is moving fore/aft, changing the distance between the control column and the aileron bellcranks very slightly. The change is very small.

Not I said if the flaps and/or ailerons have no twist in them.
The advice given so far is good, but if you are checking alignment of ailerons and flaps and some of them are twisted, you will not get a proper result.

On the RV-14 and 10, the leading edge of the flaps are designed to be lightly touching the rear spar at the inboard end when fully retracted.
Once this is adjusted, the rivets in the top flange of the flap spar should all be the same distance aft of the top wing skin trailing edge. If they are not, then there is a twist in the flap.
You can also check for twist by placing a digital level on the inboard and outboard ribs of the flap or aileron. If twist is found, the it will have to be compensated for , when doing the control system rigging (I.E., don't align an untwisted aileron to the outboard end of a twisted flap.......)
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