When to drill wing leading edge ribs to spar?

Two simple questions for you all:

First question: In the wing skeleton assembly section, "main rib/spar assembly" subsection, the instructions say to fit the main ribs (W-710, 711, 712) to the spar and drill. It does NOT say to cleco and drill the W-709 leading edge ribs to the spar at this time. However, I think I want to do this now, before I rivet the main ribs to the spar, since the main rib web interferes with backdrilling the leading edge rib through the spar. I have already drilled the main ribs to the spar and unclecod them, so now seems like the time to install the leading edge ribs and drill them. Is that what other people did?

Second question: When drilling the leading edge ribs to the spar, does the leading edge skin need to be clecod to the ribs to maintain alignment, or does it not matter? I think the answer is "doesn't matter" since alignment should not be significantly affected by adding the skin. Tell me if I'm missing something.

Thanks.

I have an RV-8A kit, and it sounds familiar, i didn't do the drill at that time, i did it later in. It really doesn't interfere if you use a long drill bit (the ones that flex) you can easily get them in there without any issue.

As for the leading edge holes, i drilled them after i have the entire leading edge assembled (clecoed) again i came from below with the long flexible drill bit from the trailing edge side, again no issues.

You'll enjoy the wing kits, theres LOTS less detail in the instructions there compared to the empennage kit.

also welcome to VAF!
Mark

In theory that would work

But I basically followed the instructions and drilled the rib/spar holes with the leading edge assembly clecg'd together. As Mark mentioned, there really isn't any interference and the ribs are easily drilled.

I would caution you to review drawing 10A and understand the rivet pattern for the two most inboard -709 ribs to spar (Front Spar Rear View). I can't remember exactly but there is a difference between the prepunched holes in the ribs compared to the spar. Look at the drawing to understand which holes to drill.

Interesting bio/profile page you have.

Drill later

mse103 said:

I have an RV-8A kit, and it sounds familiar, i didn't do the drill at that time, i did it later in. It really doesn't interfere if you use a long drill bit (the ones that flex) you can easily get them in there without any issue.

As for the leading edge holes, i drilled them after i have the entire leading edge assembled (clecoed) again i came from below with the long flexible drill bit from the trailing edge side, again no issues.

You'll enjoy the wing kits, theres LOTS less detail in the instructions there compared to the empennage kit.

also welcome to VAF!
Mark

Click to expand...

Welcome
I concur.
I'm building a 7a. I drilled them when I assembled the leading edge with clekos. Long drill bit. No problem. Also, as Dan mentioned, check the plans. Don't drill new holes in the spar. Drill from the spar into the ribs.
Now riveting...that's another issue. I elected to use LP4-3 and LP4-4 pulled rivets. I double checked with Vans first.

That is a good alternative that Larry has proposed. I considered this, but just decided to go for the gold. I didn't think it was too bad at all but it is a little challenging to hold the offset rivet set centered on the universal heads.

I'm right at this stage of the wing build. I match drilled the leading edge ribs without the skins. Without the skins is how the instructions to say to drill the main ribs, so should be the same for the leading edge ribs.

I noticed you are using One Note for your build log. That's also what I am using. I like it....easy to organize and use and it's free.

I just did this step about 3 days ago...

I drilled my leading edge ribs to the spars with the entire leading edge assemblies clecoed together. I assembled all the ribs to the skin and then mounted the whole assembly to the spar with the wings already in the jig (top skins were clecoed on as well).

You can do the pre-punched ribs either way, really, but you'll need to have the leading edge skins in place to drill the inboard-most rib and the tank joint plate anyway. These ribs are not pre-punched and need to be drilled in assembly with the skin to locate it on the spar. So I just chose to do the whole assembly at once.

But, as was stated, be sure to drill from the spar side to avoid drilling holes in the spar in the wrong place. A 12" drill bit makes this a non-issue even with the main ribs in there. My main ribs were already riveted to the spar (wings already jigged) when I did mine.