Root rib fitting

[samiam]

For some reason I have been really fearing the root rib fitting, but there is nothing left to do on my wing at this point, so it needs to be done. I have the older kit, so I have an angle that is drilled but will be making it from a stock rib.

After reading a bunch about it, it seems that the build should go:
-Level/square the wing box thoroughly
-Cut off flanges of aft rib and trim for spar cap
-Align the rib level and via the tooling holes
-Once the aft rib is clecoed in place, repeat for forward rib

Does this sound basically right? Am I missing anything? Any tips/tricks?

[jowens]

Did you enlarge the hole in the forward root rib? Remove the material between the two lightening holes.

Also, not sure if you have riveted on the main ribs. If you have not, consider updrilling the wing bolt holes to 3/8" with a drill press and the spars carefully clamped together. numerous posts on wing rigging available :)

I wish i would have test fit my wing skins before I drilled the root ribs. The skins are "a point of truth" and a good confirmation of the root rib location measurements. My root rib location was ok, just would have been less stress.

[samiam]

Did you enlarge the hole in the forward root rib? Remove the material between the two lightening holes.

Also, not sure if you have riveted on the main ribs. If you have not, consider updrilling the wing bolt holes to 3/8" with a drill press and the spars carefully clamped together. numerous posts on wing rigging available :)

I wish i would have test fit my wing skins before I drilled the root ribs. The skins are "a point of truth" and a good confirmation of the root rib location measurements. My root rib location was ok, just would have been less stress.

Did not yet do the "forward root rib mod" but plan to do so.

I did mate my spars and updrill the wing bolt holes with a drill press.

The ribs are only updrilled and clecoed on - I wanted to wait to rivet until after the root ribs were done to make sure I wouldn't have clearance issues.

I am considering the wing skin test. Upper or lower? Should it matter?

[Bryan Cotton]

Mike,
Wait until your skins are all clecoed on. Fit the root rib by hand so it looks good, then clamp to the angles. Once clamped go wild with the drill. This is really pretty easy. Also, open the hole in the forward root rib now, before you do any mounting. Gives better access.

[samiam]

Mike,
Wait until your skins are all clecoed on. Fit the root rib by hand so it looks good, then clamp to the angles. Once clamped go wild with the drill. This is really pretty easy. Also, open the hole in the forward root rib now, before you do any mounting. Gives better access.

Thanks for the advice, I'll get started on doing all three wing skins (exciting!) and then fit the root rib.

[jowens]

Both, if practical for you. Rest the clecoed wing structure with the main spar flat on two saw horses- the wing vertical, forward ribs down.

[Bryan Cotton]

Here is one post about the root rib:
viewtopic.php?f=39&t=578&start=700

And another wing build post:
viewtopic.php?f=39&t=578&start=600

Go to the next page after that last link and you will see my root rib clamped to the angles and drilled to the skins. I am a fan of horizontal wing assembly but would agree they are both viable.

[jowens]

Consider not pilot drilling the root rib to wing skin holes until you match up the wing root gap seal with all three wing skins cleco'd in place.

[Bryan Cotton]

Jim,
If you have CNC holes in your skins/doublers then I disagree. You want to pilot drill the root ribs. I used Bob's neat trick for marking the doublers for trimming:
http://n982sx.com/sonexlog110/index8.html

Somewhere I have my own picture- will see if I can find it.

Edit: found it!
viewtopic.php?f=21&t=2799&p=24132&hilit=Thx+bob%21#p24132

Second edit: any hole that falls under the wing walk/root doubler should only be piloted to #40, until you fit those parts.

[jowens]

My suggestion is to validate the wing skin pilot holes with the gap seal pilot holes prior to drilling the root rib pilot holes. This has nothing to do with trimming or installing the gap seal.