Main ribs primed and riveted to front spar

Over the last two weeks, I cleaned and primed all of the main ribs for the left wing.  I also finished riveting all of the platenuts on the upper and lower flanges of the main spar, which needed to be redone since Vans replaced my front spars a few months ago.  After I had my system down for installing the platenuts, I was able to finish all of them in about two hours.

Yesterday, after all of the platenuts were complete, I worked with Jim to rivet the main ribs to the front spar.  I was a bit worried about this process, but it all went very well.  Out of seventy or so rivets, there were only two I wasn't totally happy with, but both were acceptable.  An excellent days work!  I made the mistake of riveting the outboard rib, which only gets riveted to the rear spar at this time.  I started today by drilling out those five rivets, and proceeded to rivet all of the ribs to the rear spar. Several different size rivets are used for this particular section, so I was frequently referring to the rivet callout on the plans.  The left wing skeleton is now ready to be clamped to the wing stand where most of the remaining wing construction will take place.  This coming week I will complete all of these steps once again for the right wing.

Left side ribs cleaned and ready to be primed

Priming in progress

All left side ribs ready to rivet to front spar

First ribs attached to front spar

Riveting teamwork

All ribs attached

Riveting last few outboard ribs to rear spar

Rear spar attached to main ribs

  

Main ribs ready for primer

I've had the majority of the work on the main ribs completed for some time now, but I hadn't yet decided which holes I was going to drill / increase in diameter for items such as pitot and static lines, coax, and AOA tubing.  All of the holes are drilled for the 3/4" conduit (purchased from Vans) that I will be installing for most of the wiring. The middle hole on most of the main ribs is pre-drilled to 7/16", and is therefore left alone.  The bottom tooling hole was opened up to 3/8", which is the size specified by the SafeAir1 pitot / static kit for grommets.  Only one tooling hole exists on the three outboard ribs, and I opened up that hole to 3/8" also.  It was not necessary to modify the outermost rib.  This was the last step that needed to be finished prior to priming all of the main ribs and attaching them to the spars.

Conduit holes drilled to 3/4", one tooling hole on each rib opened up to 3/8"

All main ribs ready to be scrubbed and primed

Tank baffle work

I needed to fit the rear baffles to both fuel tanks, so I spent a little time getting them ready to be match drilled to the tank ribs and the skin.  I removed the vinyl from the rivet lines, and deburred all of the edges.  With that finished, I clecoed the baffle to the right tank and match drilled all of the holes that attach the baffle to the skin, and then the ones that attach the baffle to the tank ribs.  The same process was completed for the left tank as well.

Vinyl removed from rivet lines

Baffle edges deburred

Baffle match drilled to skin and ribs

Fuel tank prep

I took a slight detour from the plans and did a little work on the fuel tanks.  I already had all of the fuel tank ribs deburred and straightened, and I wanted to attach them to the skins.  I hit the nose of each rib briefly with the Scotchbrite wheel to remove any bumps around the notches, which allowed the skin to fit well.  As many builders have discussed on their build logs, it's pretty challenging to attach the skin to the ribs for the first time.  I found a good description of what sounded like a practical method on Jason Beaver's RV-7 builder's log, which I modified slightly.  Here are the steps I used to cleco the skin to the tank ribs:

• Cleco the entire upper surface of each rib to the skin
• Place two 2x4s stacked on top of one another on the floor, and place the back of the ribs on top of the 2x4s.  This keeps the skin off the floor
• By pressing down on the leading edge of the skin, it becomes easier to align the holes between the ribs and the skin.  Place clecoes from the leading to the trailing edge
• A pick can be used to align the holes before clecoes are inserted

Once both sides of the tank were clecoed to the ribs, the tank was placed in the tank cradle and all holes were match drilled.  The rib locations will now be marked for future reference (which rib goes where), and everything will be disassembled.

Tank ribs clecoed to upper surface of skin

Tank in cradle prior to match drilling

Skin match drilled to ribs

First portion of tank assembly complete

Wing skeleton assembly

Everything has been progressing nicely with the wings.  I finished riveting the rear spars a few days ago, and assembled the right and left wing skeletons today to match drill the rear spars to the main ribs.  It takes longer to get all of these components clecoed together than it does to match drill them.

Once the rear spars were match drilled to the main ribs, I attached the outboard nose ribs to the main spar and match drilled them also.  The inboard nose ribs make up the fuel tank, and are attached later.  A few holes exist in the main spar that don't exist in the ribs, so the spar is used as a guide to drill those holes.  A 12" drill bit works well for this, which allows you to flex the drill away from the ribs and keep the drill bit in correct alignment.  With that completed, the nose ribs were labeled, removed from the spar, and all holes were deburred.

Left rear spar attached to ribs and match drilled

Right outboard nose ribs attached and match drilled

Wings assembled - nearly ready for rivets.