What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Wing tip/aileron misalignment

B

BruceP

Well Known Member
So...the wing tips are on, the flaps and ailerons are rigged perfectly(used the W-930 aileron jig to verify)...and the wing tips are way off. Both are lower at the aft edge than the ailerons. The left one is 7/32's lower than the aileron,

IMG_1716_zpsd8xsq4c8.jpg


and the right one is worse, 15/32's.

IMG_1720_zpsgjayudlz.jpg


They look huge on these close-ups!

I'm assuming fairly major surgery is required to fix the wing tips, which I'm not sure I'm competent enough to tackle. Or maybe I just dread doing it. My question is...how much will this mismatch affect the flying characteristics if not fixed?
 
It looks like your wingtip mounting screws are already in so this first tip will not help you.
Maybe it will help others.

I drilled all my mounting holes #40 and then made the comparison you show. One of my tips was down. I pulled a rolling table with an automotive jack under the wingtip trailing edge and jacked it up to provide plenty of upward pressure. Then I re-drilled the mounting holes #30 before finishing to #6 flathead size. It came out perfect.

HERE is a link to that day in the shop

I understand from reading this site that some have split the trailing edge, jigged it to the correct position and epoxied the trailing edge back together. On the surface, it does not seem to be that much of a big deal to accomplish but I have never done it so YMMV.
 
Last edited:
I've always wondered if splitting the trailing edge as mentioned wouldn't put a twist into the tip. Anyway, even if you have installed the screws for the tips you can still take Bill's first advice. Lay up a strip of lightweight glass inside the tips under the screw holes. Then fill the holes with flox. Now you can reposition and redrill the tips. It's actually pretty easy as glass work goes; you just have to be patient twice while the resin sets.

To answer you other question, it really won't affect the flying characteristics that much. But after aligning everything except that, it will bother the heck out of YOU, so it would be worth your time to fix it.
 
My tips were both low as well. I did force them up prior to drilling--no help--they just sprung back down after clamp was removed after drilling. There was simply no (play) to allow them to move relative to the wing as they fit very tight to the end rib. I ended up spliting the rear of the tips along the trailing edge and re glued so they lined up with the aileron.
 
nedricher said:
My tips were both low as well. .... I ended up splitting the rear of the tips along the trailing edge and re glued so they lined up with the aileron.
Click to expand...

Yep, me too. I thought it was going to be a worse procedure than when I actually did it. Both my wingtips were off by 3/8" or slightly more. They corrected with no problem.
 
Wing tips

Vans will say it aint not big deal don't worry about it as it does not effect the flying. Personally couldnt stand it and preformed the wing tip surgery to make them line up.
 
Thanks for the replies everybody.

At the time I did the tips I was more concerned about how they fit at the leading edge and they seemed to naturally position themselves well there. That pretty much dictated how the rest of the alignment went, at least for me. It seems that if I were to reposition and re-drill the holes I will not get the good positioning up front?

If I split the rear, would I have to reposition the ribs, particularly the W-916, or it would create a "ski jump" if I didn't?

Last question, anybody have photo documentation of splitting the rears?
 
Line up the trailing edge to be colinear with the rigged aileron, drill, and then use whatever filler you require to adjust the leading edge fit.
 
Here's a pic of how I cut and reformed the trailing edge of my wingtips.... for cutting, I just used a cutting wheel in my Dremel tool.

Now they line up and all is good. This was just another of those steps that seemed a bit scary, but once started it wasn't a big deal to fix it.



2u4ndyq.jpg
 
I've been tempted to fit my tips before the wings are installed but was warned by other builders to wait until ailerons and flaps are installed so they can be aligned properly. Seems they might still need some surgery even then.
 
I've just been finishing off my wing and doing the wingtip mounting. One wingtip is a little long by maybe a half an inch. I can trim that off I guess. Not sure if I'm going to do that now or not.

I understand that everyone wants their plane to look good sitting on the ground but I'm not sure I totally understand the desire to have the ailerons perfectly aligned with the wingtips. Sure you can install the alignment jig and get them perfect with some work but what is this really doing for you? In real life the jig won't be installed and sitting on the ground it's it likely that the ailerons will be slightly deflected? I'm not far enough to tell if this is indeed true, just my thought. Any clarification on this point would be helpfull.
 
rapid_ascent said:
I've just been finishing off my wing and doing the wingtip mounting. One wingtip is a little long by maybe a half an inch. I can trim that off I guess. Not sure if I'm going to do that now or not.

I understand that everyone wants their plane to look good sitting on the ground but I'm not sure I totally understand the desire to have the ailerons perfectly aligned with the wingtips. Sure you can install the alignment jig and get them perfect with some work but what is this really doing for you? In real life the jig won't be installed and sitting on the ground it's it likely that the ailerons will be slightly deflected? I'm not far enough to tell if this is indeed true, just my thought. Any clarification on this point would be helpfull.
Click to expand...

It's simple a*** retentiveness. People like things to look perfect. I guess I am one of those people too, because I will be doing whatever it takes to get it to line up. But there is no aerodynamic requirement.

My I ask what is this alignment jig you guys are talking about? It doesn't exist on the -4. I have just taken a piece of wood and drilled holes to align the wing and aileron tooling holes on to the same line and I drilled them out to 1/4" to take an AN4 bolt. Is this jig anything more elegant?
 
Jig

sblack said:
It's simple a*** retentiveness. People like things to look perfect. I guess I am one of those people too, because I will be doing whatever it takes to get it to line up. But there is no aerodynamic requirement.

My I ask what is this alignment jig you guys are talking about? It doesn't exist on the -4. I have just taken a piece of wood and drilled holes to align the wing and aileron tooling holes on to the same line and I drilled them out to 1/4" to take an AN4 bolt. Is this jig anything more elegant?
Click to expand...

I don't know the part number but it does fit the 3 so it should fit the 4. It's a piece of flat stock drilled to fit the bellcrack bolt. It rests against the spar so when in place the aileron is locked into a nuetral position to set the pushrod length.
 
Proper wing tip to aileron alignment requires fitting the wing tip to a wing while the aileron is fixed in the neutral position, and aligning the wing tip trailing edge to the aileron T.E..
The wing tip is more than flexible before installation to make it possible to cause the trailing edge to raise of lower by a half inch or more depending on how it is positioned.

Splitting the T.E. to correct a misalignment is inducing a twist in the shape of the wing tip, but probably not enough to cause any aerodynamic issues though it is many little details like this that make the difference from one builders airplane beating the quoted speed specs., and another one being slower than the specs.
 
Last edited:
Alignment Jig

RV-9 - DWG 15 - Detail C-C.

You can use this alignment jig to position the ailerons, clamp or fasten them in place, then fit the wing tips. take some measurements with the aileron jigged in place so you can verify that it hasn't moved while you are fitting the wingtips.

If this wasnt used during the intitial fit up of the wingtips, then the wingtips are probably off.
 
You must log in or register to reply here.
Back
Top