Started working on the right wing this week. Thankfully most of the parts are already primed and ready to go (ribs, skins, etc) so hopefully it will go a bit quicker. Also it's easier already having done one, although I noticed from my log that I was at the same point last September, a lot of the detail is fuzzy. Flipping the plans in my head is interesting too (Van only gives you the left views).
The first step is to unbox the right wing spar and get it all marked up. The plans only show the left wing, so you have to mentally flip everything. I do *not* want to build an upside wing, so it's marked everywhere which way is up and down as well as forward and aft (and inboard and outboard for that matter).
The left wing was finished several months ago, so although everything is familiar I'm paying extra attention to make sure I don't do something stupid.
First step is to mount a boatload of nutplates that will eventually be used to bolt the right fuel tank to the wing. The nutplates are attached with flush rivets so the skin will sit flat, so first we drill a lot of countersinks to accept the flush rivets.
Closeup of the countersinks. These are done with a machine countersink tool.
Gotta say that even though I've already done this once, it is more than a little disconcerting to go plowing into a 12 foot chunk of very expensive anodized aluminum. You do not want to make a mistake on this.
Here are all the nutplates clecoed in place and ready to flush rivet.
And here is what it looks like once riveted. I used a mirror so I wouldn't have to keep leaning over to check my progress.
Once the nutplates are riveted, the center hole is machine countersunk to accept the #8 screws that will attach the fuel tank to the wing.
Once those were done, it was time to install nut plates for the inspection covers that are on the bottom of the wing. There are 3 inspection plates per wing.
There are a lot of nutplates.
Once those were done, a couple of #4 nutplates were installed in the root of the wing spar. These are later used when attaching to the fuselage (no, they are not the main spar bolts - those are huge).
Back side of the #4 nutplates.
Figured I would put in a picture of a hand squeezer since I don't think I've shown how it works before. Basically there are some dies in the throat of the tool, and squeezing the handles together closes the dies and creates the shop head on the rivet.
This is a view of the finished shop head (which is on the back side) after squeezing. The rivet is the flattened copper colored disc at the top of the nutplate.
Next project is to fabricate the tie down bracket. They give you the "T" shape metal, you cut it to length, tap it for a 3/8" bolt, then drill and mount it to the spar.
Close up of the tapped end of the tie down bracket.
Had my first major oops with this part. The bolts (AN3-5) are torqued to 20-25 inch pounds. My torque wrench didn't go quite that low, so I "guesstimated" and in so doing stripped out one of the nutplates. ARGHH!!.
This was my first experience trying to cleanly drill a bolt out of the nutplate so I could replace the nutplate. Not fun.
What I ended up doing was mowing most of the bolt off with a dremel cutoff wheel, then drilling it out.
Went at got a new inch-pound torque wrench the next day that goes down to 20 foot-pounds. Don't want a repeat performance. I'm really glad this happened when I could get to it. If it happened later, drilling it out through and access panel inside of the wing would have been a major pain.
Once that was all done it was time to work on the rear spar.
Reaming out the hole in the spar doubler for the aileron pushrod tube with a step drill.
Completed doubler. The upper part will overlay the spar and reinforce it.
Once the rear spar parts were fabricated, drilled and deburred they were all primed. I never remember to take a picture during priming.
Working on the main doubler at the root of the rear spar.
Riveting the rear spar together.
Once the rear spar was complete the main and rear spars are clecoed together with the main ribs. Starting to look more like a wing. Checking my logs, what I did this week took almost 3 weeks last time. Made really good progress.
