Wing construction & related descisions

Working on laying out my Left wing. Ribs & angles are drilled to the Phlogiston spar. Working on drilling the main ribs to the rear spar and I realized I made an error and drilled one hole for the outermost rib that won't work with the aft flange. The blue dot is where the outer/lower hole drilled in the spar lands on the rib flange. I have two fixes in mind.

1. double up the inside of the rib flange with a 2024 5/8 x 5/8" .032" angle and disregard edge distance on the lower hole.

2. cut the flange off completely and replace it with a piece of 6061 3/4 x 3/4" .063 angle. I prefer this route since it ties into both the angle on the aileron hinge bracket and the outer plate W-414.

RV-4 Wing construction by James Soutar, on Flickr

RV-4 Wing construction by James Soutar, on Flickr

Put in the bad rivet and simply add two extra rivets in the spaces between the lower rib flange rivets.

rivet edge

what gil said, i agree and would do the same. been there done that. i will not learn if i do not ask.

Do you mean like this? Then simply trim away the flange at the lower two rivet holes. The only trouble I foresee is that the instructions say to "intersperse" the aileron mount rivets meaning they go in between the rib flange rivets? My math tells me they'd be inboard of these rivets by 1/4" or more. I can also use 1x1 angle instead of the 3/4x3/4 to give me even more clearance here.

aftsparfix by James Soutar, on Flickr

No, minimum pitch for 1/8 rivet is 1/2 inch.

Insert the bad rivet, and split the distance between the next two rivets for the extra rivets.

This puts one in the center and one 1/2" above the bad one. If you want a bit more strength add a flat 0.025 or 0.032 plate to reinforce the rib flange.

Ok, thanks Gil.

Jig?

Hi

Have you built the whole wing lying down like that?

If so I fear you will have far more serious problems with twist and that hole will be the last thing on your mind when you come to test fly. The wing should be in a jig to ensure main and rear spars are parallel
!

Steve,

I was wondering the exact same thing!

WAM120RV said:

Hi

Have you built the whole wing lying down like that?

If so I fear you will have far more serious problems with twist and that hole will be the last thing on your mind when you come to test fly. The wing should be in a jig to ensure main and rear spars are parallel
!

Click to expand...

The wing is about to go in the jig for the next stages of the build. Up to now I've only fit the wing ribs/angle reinforcements (square) to the main spar. I'm now working at drilling the main ribs to the rear spar (again, square) at the correct stations. Once that's done it will be fixed into the jig and squared/plumbed up as per the instructions. I am a bit apprehensive about that next step of measuring and drilling the reference holes in the spars so I can run plumb bobs. It sounds straight forward enough but if anyone has some tips or tricks for this extremely important stage of the build I'd love to hear them.

Hope

Hi

I sincerely hope it will work that way!!

Drilling the spars is no big deal, but I have never heard of it being done with the ribs attached.obviously you cannot measure the rear spar through the ribs but this could be done from the bottom. The top is more problematic but measuring along the web and using a square to carry the mark across the main spar should do it.

Not sure I follow... Up to now I've been following Van's building instructions in the manual. The spar is the prebuilt Phlogiston spar so I'm not drilling any holes in it. Just match drilling the rib reinforcing angles to the spar itself, positioning the ribs to the angles and drilled the the angles to the ribs. Nothing is riveted yet so all the ribs will be removed when it comes times to mark out the reference holes in both spars for running the plumb lines. I don't think I've done anything not spelled out in the building instructions but I certainly considered fitting everything up with the spar in the jig. It just seemed irrelevant either way. In reality the whole assembly is pretty easy to shift around to get it square and any twist out. It's not until both spars are clamped in the proper position relative to each other and the skins drilled (mine are completely undrilled) that everything is locked into position. At that point any warp in the wing would be impossible to remove.