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Wingtip Bulge

BGS

BGS

Well Known Member
Today I have been working on the wingtips and everything was going pretty good. When I match drilled the holes into the wingtip and clecoed, everything looked really good. I then installed the nutplates and dimpled the skin, put on the wing and now have a bulge in the rear of the tip and also it looks like the tip is sagging.

I took the tip back off and checked to see if it was binding anywhere and does not seem to be. Not sure what could be causing it.

The tips was also to long by about 3/4" so I cut that off. If needed could separate the back of the tip and re-glass to see if it will fix the issue. Also, do not have the wingtip rib in place yet, that may also bring things back into place but do not thing it will fix the sagging look.

Here are some pictures, hard to see but you may get the idea. Any help would be appreciated.

Thanks

12576202

12576219

12576228

12576231



http://www.briansrv10.com/wings-pictures/wingtip-bulge-problem/
 
I seem to recall having a slight bulge there too that I need to go back and fix later. Most likely it is from the W-1016 wing tip rib being too far aft which is causing the fiberglass to expand out further than the sheetmetal. You could try to see if that is where for sure the bulge is occuring and move the rib slightly forward. You may need a new blank rib and re drill it in the proper position if that is the case.

https://skydrive-df.live.com/#cid=3B3E6F879AB2ED26&id=3B3E6F879AB2ED26!15509
 
You can gain some mounting position flexibility

The way you drilled the mounting holes determines how the tips and wings are going to align. Once drilled you don't want to mess with them. I built an RV-6A so I am not familiar with the detail design of your tip but I have made several different tips for my wings. I would have to fix the "bulge" problem if it were my airplane and I would do it with some type of web/rib to hold it in conformance with the airfoil. I have bent an aluminum rib and I have fiberglassed the closure on diffferent tips to address this airfoil conformance (bulge) problem. Both ways worked fine.

The sag appears slight in the photo but it and the bulge may be the result of the position of the mounting holes and the methods used to locate them. There may be some sag in the original alignment and there may be some holes in conflict. Anyway, without going into all that, if you replace some or all of the platenuts with floating platenuts and drill out the screw holes in the tip with a 3/8" drill to accept the wing skin dimples some unintended installation stress may be relieved and both problems may go away.

Bob Axsom
 
I had all kinds of trouble with mine also aside of the left tip being 1/2" too long. I repositioned, re-drilled, re-riveted the wingtip aluminum rib three times and still it was off. I ended up throwing the rib out and I fabricated a new rib out of 1/4 birch plywood using the ailerons in the neutral position as a template. I cut the rib a little undersize to compensate for the wingtip fiberglass thickness. I then re-split the wingtips trailing edge and prepped the areas for bonding with 36 grit Zircon and re-installed the tip, floxed the new wood rib in position and clamped the tip flush bottom and top and in line with the aileron in neutral and flaps in reflex positions. When cured I removed the tips, cleaned up the flox squeeze out and glassed the new ribs in with 2 layers of BID and rebonded the split in the trailing edges. It added a little weight to the tips but I am pleased with the results now and feel the few added ounces were worth it.
 
Brian
It looks like your w-1016L and R at least in the picture are in wrong.
in the picture you have it upside down I think. Take a good look at them again and the plans.

Geoff
 
Wintip Bulge

Thanks for the replies. Took all that was said and went back to see what I could do. Started with re-dimpling the holes in the wing skin, seems that it was not a real clean dimple. Also noticed that the skin from dimpling caused it to bend upwards on the bottom. Used a seamer to bend them back to where they should be. I then installed the wingtip rib, which was just laying in there before. made the measurements and installed while on the bench trying to keep everything straight.

With those adjustments, and then when installing the screws into that attach it, instead of starting at the front and moving back, I started in the middle and randomly did them till all where in loosely, then went back and tightened in skipping a couple here and there.

All these seemed to make it a much better fit. However, still have the sag and even when the tip is off, it has a little. Assuming this is mostly from when the tip was made from the factory. In the pictures you will also see a spot at the rear of the tip by the aileron, there is a part of the tip that has a gap and hoping that this can just be filled in with filler and smoothed to match the aileron.

If for any reason anybody thinks this is not a good fix or should be trying something else, please chime in. The help is greatly appreciated.

Thanks

here are all the pics, the last 7 are after the re-work

http://www.briansrv10.com/wings-pictures/wingtip-bulge-problem/
 
Brian,

Looks like you still have a gap there in Redone2.jpg. Check what Geoff said, i had the same problem.


Lenny
 
I did install the 1016-R into the 1015-R wingtip, with the web towards the aileron and the flanges pointed towards the tip. This is how I interpreted the plans. Is that wrong?
Seems as if they were upside down, there is no way the aileron would line up unless it is deflected down a bit.
 
I just looked at both of my wing tips and they appear to point up just slightly. I remember that I initially reversed the stiffener because I used piano hinge instead of the screws to attach them. I needed to have the flange pointed outside, so I used the left on the right side etc. remember, when you line them up the flaps are in a negative reflex position, this means the trailing edge is actually pointed up from neutral. As I recall the plans call for you to push the flap as far as you can to reflex until it contacts, then align the aileron with the flap and then the tip with the aileron. when you do this does your wing tip align?
Bill
 
When I did install the rib, It does align with the aileron when it is in a slight reflexed position. Everything does line up quite nicely now except for the slight indent on the bottom. I was hoping I could just fill that in and smooth out.
 
Is the 1016 in the most rearward position you could get it? I guess you could fill it in , but I still don't understand why you have such a pronounced dip. If you loosen all the screws and then install the rib and try to rotate the tip, does it go away?
 
Tried that and it does not go away.

I did initially have it back farther rearward, but this caused the wing tip to protrude above the aileron instead of the bottom. So I chose the to have it on the bottom so it could be filled.

Having all the screws loose and moving the tip does change the gap a bit but just moves it around. The gap also is not as bad as the picture shows, it is only about an 1/8" at the worst spot.

I did the other tip the exact same way and it turned out perfect. Could this be possibly a badly made wingtip?
 
I guess it could be a bad tip. Try measuring the circumference of both. they did not send you a mis-marked part did they? the ribs should be mirrors of each other
 
Landing light

Brian,
Wish I could help with the problem, but way behind you. I would like to know which landing light you have installed that I can just see in the pics?
Thanks.
Johan
 
Thanks Brian

They look real nice. Do you have them in both wings? WigWag possible?Are you putting in the standard Vans landing light as well?
Apologies for thread shift!!
Johan
 
I did put them in both wings. Very easy to install. They are also LED so the wiring is very easy also. They are wig wag capable and will be using that option. I am not using any of Vans lights, the tips will have the AeroLED Pulsar Nav/Strobe combo.
 
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