Just wondering if anyone else has had this problem with the skin fit on the outboard top and bottom skins. On both wings I ran into a problem with fitting the wing skin. Most of the holes lined up on the outboard skins but when It came to clecoing to the outboard rib, only about half of the holes lined up. The top half of the rib holes were about half lined up and I really had to work to get clecoes in. The alinement problem was up and down not side to side. Some I absolutely couldn't get them to line up and ended up with a fairly larger hole that I think I will have to use an "oops" rivet in because the 426 won't have enough to hold. I worked for a long time trying to get them to line up but didn't want to force them. On the left wing, a couple were forced and ended up having a cracked dimple when I riveted them together. Just seems odd that it happened on both wings and in the same spot. Is there an alinement problem with all the wings or is it just mine?
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wing skin fit problem
- Thread starter ditch
- Start date
robjohnson
Well Known Member
How about a picture? You shouldn't have troubles putting that skin on -- do you have the rib oriented the correct way? Check the plans and the flange direction carefully. That is about the only thing I can think of, as long as you are sure there is no spar sag and it is squared up....
It's a little late for pictures since the holes are now drilled but as far as the rib orientation, there are only 3 ribs that fit for the most outboard ribs and the flange is in the right direction. Trust me I checked many times to make sure. There was no wing sag either and with 95 % of the holes filled with clecoes, it should be square also. Just had the holes in the outboard rib not match up right. Struck me funny because so far haven't had any problem with hole alinement except for the end ribs on both wings. Many other holes in the skin were really tight but they went. Like I said, ended up with some holes bigger than I would like to see but I couldn't see any other way around it.
LettersFromFlyoverCountry
Well Known Member
Is the skeleton in a jig? I found in my construction that if you cleco each rib, from the main spar down to the rear spar, they don't line up right when you get to the last few clecos, regardless of where they are. Don't ask me why. They don't.
But if you go laterally in inserting the clecos....all the main spar ones, then the next row all the way across etc., they line up fine.
But if you go laterally in inserting the clecos....all the main spar ones, then the next row all the way across etc., they line up fine.
Hey Ditch, I just went through fitting and riveting my top skins. I did have problems getting things straight but most of my problems were caused by my jig. My shop is a small shack with a wood floor and I found that as the outside temps changed my stand would move, only slightly but none the less enough to change the way it was set up. The other thing I noticed that hadn't been mentioned is that just putting a jack under the center of the rear spar (when hanging in the jig) it would push up in the middle of the front spar and and the rest would still be to low, to fix this I had to use a straight length of 2X4 and use it to distribute the jacking over the whole rear spar, which in turn removed the sag the length of the spar. I got good at the squaring process because I got to do it every day before I could work on my wing.... it was so out of wack just from sitting over night. From where I'm at in my kit and how perfect every thing has fit I can't imagine yours would be any different. Hope this helps.
P.S.
I just remembered another thing that kinda screwed me up was when I would clamp my rear spar down before I lifted the sag out. If I straightened it all out first and clamped the rear spar last life was good.
Ted
P.S.
I just remembered another thing that kinda screwed me up was when I would clamp my rear spar down before I lifted the sag out. If I straightened it all out first and clamped the rear spar last life was good.
Ted
skyyking56
Well Known Member
Tight on the last 2 aft holes
Hi Greg,
I had the same experience as Bob.
I just match drilled my wing skins and what I noticed is that as I got down to the last couple of rivets (aft near the rear spar) is it got harder to put the clecoes in and the holes were slightly oblong fore and aft after drilling and not inboard/out board. The holes were still acceptable and I think that this must be designed into the rivet pattern to keep the skin tight so no oil canning occurs.
I didnt notice anything on the outboard ribs that were any different than the rest of them though.
My main spar holes went in perfectly aligned ( I put them in first to double check that the spar was straight which I had just done by using the fishing line check across the holes) which told me that I had the center of the jig jacked properly.
Sounds to me as if the rib holes might have been out of position from the factory if you had the problem match drilling them also.
Just my .02
Jim 7A (wings)
Hi Greg,
I had the same experience as Bob.
I just match drilled my wing skins and what I noticed is that as I got down to the last couple of rivets (aft near the rear spar) is it got harder to put the clecoes in and the holes were slightly oblong fore and aft after drilling and not inboard/out board. The holes were still acceptable and I think that this must be designed into the rivet pattern to keep the skin tight so no oil canning occurs.
I didnt notice anything on the outboard ribs that were any different than the rest of them though.
My main spar holes went in perfectly aligned ( I put them in first to double check that the spar was straight which I had just done by using the fishing line check across the holes) which told me that I had the center of the jig jacked properly.
Sounds to me as if the rib holes might have been out of position from the factory if you had the problem match drilling them also.
Just my .02
Jim 7A (wings)
Last edited:
I started by clecoing the main spar and then going down each row one at a time. (I do have the wing in a jig) Maybe that was some of the problem. Anyway, its to far along now and I looked everything over pretty good tonight and all of the holes are good except for about 8 of the top holes in the outboard rib on top and bottom. Those holes are either a little to big or oblong. Im going to put an extra strip of aluminum on the inside of the rib and rivet it as a 3rd piece. That way I can match drill so I have a good clean hole on the inside for the rivet to hold. Otherwise the hole is to large and rivet wouldn't hold. Should be structurally fine. Makes sence to having the holes slightly farther apart as you go to keep skin tight to.
bottom skin alignment
Well I have just finished scratching my head for the last day and a half trying to figure out why the botom skins on my right wing were not aligning properly. I built both wings at same time in identical stands doing the same process on each one alternating back and forth. Top skins riveted on with no alignment issues at all. Bottom skins were matchdrilled and dimpled a few months ago but I don't recal any problems when doing that. Clecoed skins on bottom left wing in the order in which I plan to rivet (to make sure that would work) and everything looks fine and lined up great. Did the same to right wing and none of my top row of holes in the spar lined up, they were all low by a 1/16th!! Checked my wing alignment in jig and it was good so I took the wing off and put it on the bench but that didn't change a thing. Just can't understand why such a difference. So after trying different variations in clecoing the skin down I finally got it to work but the gap between the tank and leading edge skins and the bottom skins is bigger than on the other wing. I ended up going across the main spar first, then down the rib and across the trailing edge spar. outboard one bay at a time. This is going to be a pain as doing the aft spar last is going to be much harder than doing the main last. This is the only way that the holes will all line up. Oh well, it can't all be easy. Still can't figure out why this happened but I can't lose anymore sleep over it.
Steve
RV7 - Fuselage ready for wings
Well I have just finished scratching my head for the last day and a half trying to figure out why the botom skins on my right wing were not aligning properly. I built both wings at same time in identical stands doing the same process on each one alternating back and forth. Top skins riveted on with no alignment issues at all. Bottom skins were matchdrilled and dimpled a few months ago but I don't recal any problems when doing that. Clecoed skins on bottom left wing in the order in which I plan to rivet (to make sure that would work) and everything looks fine and lined up great. Did the same to right wing and none of my top row of holes in the spar lined up, they were all low by a 1/16th!! Checked my wing alignment in jig and it was good so I took the wing off and put it on the bench but that didn't change a thing. Just can't understand why such a difference. So after trying different variations in clecoing the skin down I finally got it to work but the gap between the tank and leading edge skins and the bottom skins is bigger than on the other wing. I ended up going across the main spar first, then down the rib and across the trailing edge spar. outboard one bay at a time. This is going to be a pain as doing the aft spar last is going to be much harder than doing the main last. This is the only way that the holes will all line up. Oh well, it can't all be easy. Still can't figure out why this happened but I can't lose anymore sleep over it.
Steve
RV7 - Fuselage ready for wings
Ya, what gets me is that 95% of the holes lined up fairly well on mine but on the top and bottom skin, most outboard rib, the top 6-8 holes were off quite a bit. bottom half of rib lined up but top didn't. I don't think it was from the way I clecoed or I would have had many more than just those few give me trouble. And since it was on both skins, makes me think the rib holes some how were off. I did figure out how to fix the problem but said a few choice words in the process, actually many choice words
RVG8tor
Well Known Member
Bottom skin fit
Ditch,
I am having what seems like the same issue with the bottom skin on my QB wings, oddly enough this is the only skin I have to install. If I cleco from the rear spar forward, I can't get the most outboard rib holes to line up and non of the main spar holes. If I cleco from the main spar to the rear spar i can't get more than the first couple of rib holes to line up.
What did you find that worked for you? Thanks is advance.
Cheers
Ya, what gets me is that 95% of the holes lined up fairly well on mine but on the top and bottom skin, most outboard rib, the top 6-8 holes were off quite a bit. bottom half of rib lined up but top didn't. I don't think it was from the way I clecoed or I would have had many more than just those few give me trouble. And since it was on both skins, makes me think the rib holes some how were off. I did figure out how to fix the problem but said a few choice words in the process, actually many choice words
Ditch,
I am having what seems like the same issue with the bottom skin on my QB wings, oddly enough this is the only skin I have to install. If I cleco from the rear spar forward, I can't get the most outboard rib holes to line up and non of the main spar holes. If I cleco from the main spar to the rear spar i can't get more than the first couple of rib holes to line up.
What did you find that worked for you? Thanks is advance.
Cheers
Wow, sounds like you have a bigger problem than I did. Most of my holes lined up except for around 20 of them or so that I really had to work to get the cleco's in. That's not a good thing either because I noticed that when you have to work the cleco's in you can get nicks in the holes and had a couple dimples crack because of it. My worst part was the outboard rib holes towards the main spar. The holes did get elongated after I drilled some of them but I just cut a scrap piece of aluminum and put it on the back side of the rib to reinforce the rib holes. Wanted nice clean holes for for the shop heads. Sounds like your wing has some sort of distortion in it. Like the top skins are pulling the bottom rib holes further apart. Try starting in the center of ribs and working outward. Heard that sometimes helps. Other than that, call vans if it won't go. Just remember to be careful inserting those cleco's. Good luck......
I found that the holes would not line up on the rear spar and skin when I did not use a jack for the middle of the rear spar. I would jack up the middle rear spar and the hole will all fit perfectly. I guess the rear spar bends a little without a support to straighten it out.
I had a jack in the middle as well when I did mine. Everything was perfectly square but didn't make a difference. Plus, once 3 of the 4 skins are rivetted on, there should no longer be a need for it. It should be rigid enough with out it.
