Time to see just how big these things are gonna get.
Starting with the left wing, I took the now-straight ribs and set to work attaching them to the spar one by one. Just to be safe, I made a checklist of which rib should go in each position on each wing and double checked things as I went.
One potential "gotcha" I noticed was that the outboard W-712 ribs and the leading edge ribs have identical hole spacing on the spar. The leading edge ribs are meant to go on the INBOARD set of holes at each attach point. Even if the main ribs are in the wrong set of holes they can still flex to meet the rear spar in the proper location, so it'd be really easy to get it backwards.
After all the appropriate ribs were set in place, I attached the rear spar and took a step back to admire my RV-7's left wing. Compared to most of the other planes I fly, these wings are relatively small and easy to handle.
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| Oh yeah. It's all coming together. |
The #30 reamer made quick work of things. I ended up removing the nose ribs to gain easy access to match drill the main ribs. Once everything was match drilled I took one last look at things and started removing the rear spar and the ribs. I went ahead and deburred the holes on each part as soon as I pulled it off to streamline the whole process. I reattached the nose ribs to match drill them to the spar, then disassembled everything and moved on to the right wing to repeat the process.
Getting all of this match drilling done went by surprisingly quickly. Once I was done with all that I laid both of the spars back on the workbenches and set about finally attaching the tiedown brackets. I've had them done for a while now but never got around to actually installing them.
I had matched drilled each bracket with the spacers flush against the insides of the spar doublers so I knew it was going to be a very tight fit. The left wing bracket slid into place with only a little resistance, but the right wing bracket was way too tight to force into place without damaging the anodizing off the spar doubler. Most likely, the spacers shifted a tiny bit when I used the squeezer to set the rivets. I ended up taking a file and shaving some material off the spacers to allow the right wing bracket to slide into place without having to use too much force.
When bolting everything down I came across a small issue. The hardware list next to the diagram has the necessary parts in the order of bolt, AN960-10 washer (1/16" thick), AN960-10L washer (1/32", thinner), then nut.
The drawing itself appears to show the opposite, with the thicker AN960-10 washer being next to the nut and the thinner AN960-10L washer being under the head of the bolt.
I'm probably overthinking this; it probably doesn't matter all that much which washer goes where. I went ahead and installed the washers the way shown by the drawing, with the thinner AN960-10L under the head of the bolt. The tiedown bracket itself is an extra layer of material between the bolt head, washer, and spar doubler so I can probably get away with the thinner washer on that side. There's only the nut and the washer on the other side before the spar doubler, so it makes sense to have the thicker washer on that side.
I didn't fully torque the bolts just yet; I didn't want to put any torque sealant on anything in case I have to remove the brackets for some reason before I close up the wings. I'm making a list of all the bolts I'll need to torque before the first flight, and these will be added.
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| Another small job down, a few hundred more to go. |
