SonexBuilders.net

Well, it's my first call for help. The aileron tip ribs are killing me. I've been all day bending trimming trying to make them fit without success. I'm trying not to damage them beyond being able to use them so I've limited myself to trimming the trailing edges and bending the flanges some. The problem is I can't get the forward angle to match the skin angle when I square the tip with the edges. I've checked the dimensions of my cuts and they appear to be per plan. When the trailing edge of the tip is moved diagonally inward on the aft side of the skin, the angle will match up. I've included pictures. Anybody else have trouble with these? In my mind it looks like the forward angle on the rib is wrong but I'm sure it's the same rib that has been used for a long time so there must be something that I'm just not seeing. My mind works in circles and squares so the oblique angle here has got me stymied. One picture shows the gap at leading edge of rib. The other shows it square with the aft side of the tip moved. Any ideas would be appreciated.

For that one I lowered my standards and moved on!
viewtopic.php?f=39&t=578&start=520

It is down a bit on that page.

It may just be that the flange angle needs to be adjusted on the forward end of the tip rib. See if you can align the tip rib like the upper picture, drill & cleco it in place, then use a long drill bit or round file or other item to "hook" the trailing edge of the tip rib and pull it outboard until it aligns with the upper and lower surfaces (you may need to hold it in that position while you drill and cleco the first couple of holes in each surface).

Good luck!

--Noel
Sonex #1339
Wings & Empennage complete, Fuselage nearly complete, working on FWF & controls

I fought with mine for longer than I care to remember. It seems to be a common problem that has 2 solutions; live with it, or make custom replacements. I have wonderfully tight seams on all sides. It only took three attempts to get it right.

Which ever course you choose, do NOT beat yourself up thinking the poor fit is something of your doing.

Common issue with the factory part. You can either live with the big pucker at the front or make your own tip rib. It's not that hard to do. Hold up a piece of material to the end of the aileron and trace around and then add 1/2 " for a flange and bend up.

Thanks for all the responses. After searching the net more, I found posts griping about the same issue clear back to 2005. Sonex should have addressed that issue. Not all of us are good at fabricating parts. That's why I bought pre-bent parts. The rib fits squarely as long as I don't try to mate the leading edge to the skin. I'm not crazy about the stress on the skin in the pucker area. One thought I had was to make a shim to fill the gap and then just use longer rivets to finish that area. The skin would keep it's proper shape that way. I may try to make a rib just to see if I can do it. I don't have a brake so it would have to be done with clamps. At any rate just knowing that I was not the only one was helpful in itself.

Gregg