[chriscencula]

Hi folks,

1st post on VAF.net...

My RV-6plans show the inboard most rib of the leading edge (the one under the splice strip, W-408-1L / R) with the flanges pointing outboard (the same way as the other leading edge ribs (except the outboard most)). My kit is from '06 and has pre-punched skins, but no pre-punched ribs. The forward-most two holes (on on the top, one on the bottom) of each nose rib are offset span-wise by approximately 1/16th inch because the rib flange is tapered near the nose... That way the hole should remain roughly centered on the flange.

The problem I see is that the forward most two holes on the inboard most rib of the leading edge (W-408-1L / R) are offset OUTBOARD of the other holes! This would be suited for a rib with the flanges pointed INBOARD, not outboard as shown in the plans. This makes an already marginal edge distance problem much worse!

I'm wondering if the newer kits have these holes in a straight line for the inboard most rib of the leading edge skin... (I've already looked at a few builder's web sites and see that it appears the newer kits are still having this rib installed the same way as on my plans, with the flanges pointing outboard)

I'm thinking of possibly swapping the ribs so the flanges point INBOARD (counter to the direction shown in the plans), however this would mean I need a new rib since one has already been drilled according to plans and it was too late when I noticed this issue. Joe Blank at Vans support didn't see any issue with this, however his suggestion was to just keep what I have and put a small 'backup patch' on this hole...

I also wonder what other folks did regarding dimpling/countersinking this area:
1) Dimple skin, dimple splice strip, dimple rib
2) Dimple skin, countersink splice strip, non-dimpled (or slightly C-sink) rib
????

I'm initially inclined to get a new rib and swap the ribs so the flanges point inboard since that seems like the best solution from a strength standpoint, but it's about $20 + shipping + waiting to get the new part... I wonder why this rib was oriented the way it is, since riveting between this one and the next one will be somewhat tight (if the rib has the flanges pointing inboard, it would be easy to put this one on last and just squeeze the rivets).

Thanks in advance for your ideas, feedback!

Chris

 

[Transporter]

W-408-1-L/R

I'm building an 8, but it still uses the W-408-1-L/R and W-423 splice plate.

The plans call for the flange(s) to face outboard as you describe. The holes are still offset in my prepunched wing kit (received 7 Feb 08) as you have described and the edge distance is close, but is okay when checked with a micrometer.

Instructions state that the W-423 splice plate...."holes for attaching to the rib and skin can be slightly reamed (like the rear spar) to gain a better fit between the skin, the splice plate, and the rib."

Rear spar instructions referenced state: "Dimple the .040 rear spar and "touch up" the dimpled holes slightly with a sharp deburring bit or microstop countersink. This "touch up" operation removes just a small amount of metal to make the skin dimple fit better and is not critical, so it can be done by eye. Use your test patch to test the depth. The usual tendency is to remove too much metal, so use a light touch."

I just finished this process on both wings:
dimpled skins
dimpled ribs
dimpled splice plates and slightly reamed as described above.

They came out great when clecoed together-no worries. Having said that, I'm a long way off from riveting!

Regards,
Mike