M

mlwynn

Well Known Member
Hi folks,

I am building the leading edges for my RV 8. The right one fits great, no problem. The left one is the issue. When I first put it all together, I had a very tight fit, ie had to pull quite a bit to get the skin clecoed to the spar. The spar rib holes did not line up and I thought it was all one problem. So, I took it apart and gently tapped in the nosed flanges, polishing them on my fine-grit scotchbright wheel. That took care of the tightness in getting the skin to cleco to the spar. Still, the rib/spar holes did not line up. So, I released the skin from the spar and wiggled the ribs around until I could get the clecos in. In trying to get skin back to the spar, it was clear the the ribs (on just the left side, mind you) were shifted slightly towards the bottom of the spar. The result is that the skin doesn't fit properly--the ribs bulge it out towards the bottom.

So, here I am scratching my head. If I redrill the rib holes to the spar, they will be too close to the existing holes. We are talking about 5/32 of missalignment, so the holes would almost overlap. Should I think about drilling them and then putting a .032 plate over the top of the rib joint to reinforce it?

Need some guidance.

Regards,

Michael Wynn
 
Michael,

This sounds very strange. I am sure you have checked the obvious things such as making sure you have the right ribs (left hand versus right hand) and that they are pointing in the right direction (flanges pointing outboard except for the end rib). Is it possible to compare the ribs and spar from the good side with the bad side? Are holes in the spar in the same place? How about the ribs? Anyway, best of luck and let us know what you find.
 
I'm not sure it's too different, but on my -4, I fitted the ribs to the skin, then the skin & ribs to the spar. It involved allot of taking apart and puting back together, but it came out perfect in the end. I think if you had to re-drill the holes, a .032 plate on the back would be fine. I'd fly it. ~Joe
 
Hi folks,
Thanks for your ideas. I double checked that I have the correct ribs in the correct place. I had carefully leveled and double-check the spar for twist in the jig, so that is okay. It seems like either the spar or the ribs are mis-punched. The ribs are W709L. The end rib, the 709R fits fine. I am thinking about sending for three new ribs to see if that is the issue--but it seems unlikely. Also, the W709L that is the end rib on the right wing fits fine and all the right wing ribs fit exactly right. Still waiting to hear what Van's has to say. So, thanks for the thoughts. I will keep you posted.

Michael Wynn
RV 8
San Ramon, CA
 
Michael,

I had some issues getting mine to line up as well. What I found was that the ribs were ordered incorrectly. By changing these, the majority of my problems were fixed. Also be sure to take care about the 90 degree flange angles on the ribs. Once that was done they attached to the wing without issue. Hope that helps.

Danny
 
Mike,

Did you ever resolve the leading edge rib problem with Vans or by yourself? I'm very interested in your resolution as I am not that far from fitting my leading edges on my -8 wings.

Jeff
-8 wings
 
Leading Edge Fitting Issue

This has been an interesting saga. I sent a number of photos to Van's. Their bottom line was that they couldn't figure out what happened. They suggested (and are sending me) some .025 right angle stock and suggested cutting off the flange and riveting on the stock, then fit the rib and drill through from the spar to get the holes correct. I have sent for a couple of new W 709 L's to see if they are correct. I suppose I could figure it out by carefully measuring the spars and ribs. Should have some time to sort it all out this weekend. I will report back.
Regards,
Michael Wynn
 
Mystery Solved, problem solution to follow

I finally engaged my brain to sort this out. I took the ill-fitting leading edge off. I carefully measured the holes in the spar and found that they were exactly centered (so far, so good). I then measured the holes in the W-709L and discovered that they were off center by the 3/32 that I couldn't get to fit. I compared these to W-709 R ribs by clecoing them flange to flange. Definitely an offset. I appended a couple of pictures and sent the whole thing off to Van's to see what they think. They had suggested cutting off the rib flanges, riveting on a new flange and drilling to fit. If they had a run of mis-punched or mis-bend ribs, I will be surprized to find out I am the only one with this issue. Anyway, this has been a frustrating cul de sac in the building process.

Anyone else with a similar issue?

Michael Wynn
RV 8 Wings
San Ramon
 
Michael,
It will be interesting to see how the new W-709Ls fit. Cutting off the flanges and riveting on new ones seems a bit drastic to me for something that is supposed to fit right the first time. After all, it IS "matched hole" technology.

Computers ( and that's what they are out there at Vans), I would think, are typically garbage in, garbage out. I think it's entirely possible for a defective batch to sneek through. As good and reliable as they are at Vans, so long as human beings are involved, mistakes are a possibility.

I'm curious, when was your wing kit shipped to you? I will take a look at my 709Ls and compare them to my 709Rs ( ship date 2001...yeah I know) and let you know what I find out.

Jeff
 
Problem solved

Hi all,
Got my replacement W-709 L leading edge ribs. Perfect fit. Compared the the ones that came in my wing kit, the holes in the new ones are about 1.25 hole width closer to the bottom skin. That was what my fitting problem was. Have forwarded pictures and notes to Van's. Hoping they will credit me for the funky parts.

I ordered my wing kit on 5-12-05 and received it on July 26, 2005. Since the ribs were all the same, and mis-punched or mis-bent, I expect that someone(s) else are going to have this same problem.

For future reference, you can sort the problem out early by clecoing the ribs to the spar to check for fit prior to deburring, fluting and fitting them into the skin. If the edges do not line up with the spar edges, save yourself a lot of wasted time and effort.

Regards,

Michael Wynn
RV-8 Wings
San Ramon, CA
 
Michael,

Glad to see your problem was solved. I checked my ribs (2001 vintage) and found they matched up perfectly. It sounds like it was hopefully a small batch of mispunched ribs that you were fortunate enough to get, so that you could educate the rest of us to the possibility of such a thing happening. Good luck with the rest of the project.

Jeff
 
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