The Case of the Missing Scarf

November 12, 2012

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Today, I had a day off work. This was excellent news because:

1) I needed a day off work.

2) The airplane needed me to have a day off work to get some stuff done.

Really, there are only a few things left on the right wing before I can call it complete and catch the left wing up. The lower outboard skin, inspection covers, pushrods, and wingtip. I’ll probably wait until both wings are complete to do the pushrods and wingtips.

That leaves the skin and the inspection covers.

Here’s the lower outboard skin, just kind of hanging on the wing (makes for good storage).

Also, You can see I kept my extra pieces of blue tape here while I finished the inboard skin.

After pulling the skin off, I realized that I already prepped the skin through deburring and scuffing the inboard side. Nice!

Already scuffed. (If you look at the date of the linked post, it was February….of 2011. Ouch.)

I guess you also get a closeup.

Anyway, I got the C-Frame out again and dimpled all the holes.

I did not dimple the wingtip attach holes. Haven’t even thought about those yet.

After dimpling, I cleaned the skin, took it outside, and got it primed between rain showers.

Back in on the workbench, it’s drying.

I still like doing the blue vinyl stripe trick.

While the skin dries, I went ahead and deburred and dimpled the rear spar. I was so lazy when I did the inboard wing, I only deburred and dimpled the holes required to get that skin in place.

Dimpling…done.

Then, I did the same deburr/dimple trick on the remaining spars.

You can see my conduit and wire-pulling string, also.

I guess this is another angle.

Okay, primer is dry. Let’s pull off the blue vinyl before getting the skin in place.

One bay.

All the bays. Man, those clean lines look good.

Oh, almost forgot to mention. Anytime you have a lap joint with two skins, don’t forget to use the edge roller to put a little kink in the edge. It helps lay the edge down when the two skins are pulled together.

My edge roller.

Here’s a good shot of how the skins lay on top of each other after rolling a bit of the edge.

Nice seam there.

After that, I didn’t think there was anything else before getting started. (I’ll come back to this.)

Getting the skin clecoed on.

After getting the first bay riveted, I realized I had forgotten to bevel the two skin edges like I had on the upper skins.

So, here’s my plan: leave it alone. The  amount it sticks up is minimal, and the bottom of the wing is less critical than the top (so says physics). I’ll either remember on the left wing, or do it the same so they are symmetrical. I’m going to go talk to our super-smart aero guys to see if there is any real concern.

After the first bay…

Then, with much straining, pulling, pushing, stretching, etc. I managed to get the second bay done, too.

To help you see what I’ve completed, I pulled the blue vinyl off where I’d finished.

It looks soo good.

Counting rivets, that two at the top is a “carry-the-two.”

So. 3.5 hours, 107 rivets. Not bad.

Taylor, get your butt over here so we can do some more.

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Started Riveting Right Flap Hinge to Wing

November 3, 2012

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Whoa. He’s back. Again. I know the updates have been few and far between, but please rest assured: I have not been working on the airplane without updating the site. I guess that’s not a good thing either…

I spent a few hours today cleaning out the garage and reorganizing a little.

Much better. (Sorry, you don’t get a “before” shot.)

Then, I decided to work on the airplane. Since I haven’t coordinate the cousin to come over and bang out some of these bottom skin rivets, I figured I could rivet the flap hinge up until it prevents me from bending back the skin.

It should be just a couple rivets.

I do need to trim the one side of the flap hinge, though.

You can just barely see that I made a mark on the hinge.

After removing the flap.

Here’s the trim line on the outboard side of the hinge.

This is pretty self-explanatory.

This one, too.

Oh yeah, I needed to smooth out the eyelet remnants where I had snipped them off to make a centrally-inserted set of hinge pins. See this post for more.

All smooth.

Looks pretty good on the outboard side.

Same on the inboard side.

Let’s get to riveting. The rivet callout here is an AN426AD3-4.

I love these yellow bins. Highly recommended for your project.

I didn’t really feel like getting out the rivet gun (and I can’t use my no-hole yoke because the eyelets get in the way), so I made it work with my economy squeezer.

An action shot!

After 8 perfect rivets, I couldn’t help but take a picture of some shop heads.

Look at how perfect that guy is!

0.5 hour. 8 rivets. Again. Not bad for not working on it in 2 months.

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Finished Right Lower Skin Wingwalk Ribs

August 28, 2012

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Not much excitement today, just a few more rivets on the lower inboard right wing skin.

I was riveting solo today, so not many pictures either.

Here’s one of a couple shop heads. Not sure why I even took this picture. Maybe to show you that I was using some black felt to protect from dropping the bucking bar.

Boring picture, anyone?

After reaching in, under, and around the wingwalk ribs, I got all the rivets set.

And, I’m prepped for some duel riveting. Maybe tomorrow?

0.5 hour. 32 rivets. Not bad.

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More Right Lower Inboard Skin Riveting

August 15, 2012

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Today, while waiting for the DirecTV guy to show up (insert long story here about how I took the whole afternoon off to cover his time (12-4pm) and then he didn’t show up until 5:30pm), I ended up taking some time out for the airplane.

Taylor and I riveted six rivets on the inboard edge the last time he was over. It turns out, I really needed to bend the forward edge of the skin “up” in the picture to reach the aft row of rivets.

So, I drilled out three of the rivets, and was able to reach in from just below the main spar (bottom of these pictures) to buck the top row of rivets.

After setting the top (aft? oh man, we’re going to have trouble communicating with our different frames of reference) row of rivets, I worked down one rivet at a time for the two middle wing-walk ribs. (The inboard or left rib can be squeezed at the end, and the outboard wing-walk rib can be bucked by reaching from outboard after the wingwalk ribs are done.

Here’s the top row riveted.

To help me know where I was, I colored each rivet black with a magic marker after setting it.

After an hour, I made it about halfway down the rib.

From here on, I won’t be able to peel the skin back from the bottom anymore, but I should be able to reach in through the inboard rib, where the lightening holes are now big enough for my huge biceps.

1.0 hour, 33 rivets. 3 (originally perfect) rivets drilled out due to lack of planning. Boo.

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Started Preparing the Right Wing Lower Skins

August 5, 2012

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Well, after a busy morning at the SCBC, I did get an hour in on the lower right inboard skin. I’ve decided to go ahead and close up the right wing before proceeding. A lot of people wait until much later in the project (which the instructions say you CAN do if you want), but everyone who waits says there is no real benefit to waiting, so I’m going to go ahead and get them closed up now.

First, I pulled the skin off the wing, and then got to work. I spent about 30 minutes edge finishing, then another 30 dimpling about half the skin with the c-frame. (No, I didn’t forget to drill or deburr, I had done those previously.

This picture is from after edge finishing, but before dimpling.

After I finish dimpling, I’ll prime the inside surface. Then, I’ll deburr and dimple the wing ribs, and rear spar, but I’ll need to remember to countersink the flap brace.

1.0 hour.

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Finished Right Flap!

July 30, 2012

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Well, after approximately 6 months of completely neglecting the airplane, I finally completed another big assembly on the airplane. Here are the gory details.

Yesterday, Taylor and I got all the rib-to-skin rivets set, so today, we finished up the spar rivets and cleaned up a few badly set rivets. Here we are with the every-other method on the lower flap skin (spar) rivets.

Look! no clecos!

Then, we finished getting the two exterior ribs in place. I did make a stupid mistake here, though. The spar rivets are all AN426AD3-4 rivets, and I just continued with that size around the side to the ribs.

Those ribs are SUPPOSED to be AN426AD3-3.5 rivets, so when I went to squeeze the -4s, they all bent over and sheared.

Nastiness here.

Ahh!

After some mild curse words,  some deep breathing, and FIVE drilled out rivets, we realized our mistake and got the correctly-sized rivets in there.

Shiny bottom!

I had Taylor shine up the skins. (By “shine” I really mean “remove all of Andrew’s fingerprints.”)

Shiny bottom skin!

Shiny top skin.

I forgot how much fun it is to finish a big assembly.

It’s a wing!

1.0 hour, counted as 1.5 man-hours. 78 rivets, 5 drilled out.

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Right Flap Brace and Aileron Gap Fairing

December 12, 2011

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Alright, before we get too busy getting excited about two posts in a row, let’s talk a little about Christmas. This year, we decided to do a Christmas tree. A few Saturday’s ago, we ventured out into the cold (it was pretty warm) and cut down our own tree (no we didn’t, we bought it from the farmer’s market).

Anyway. There are three interesting pictures from the day.

Jack, incredulously watching us decorate the tree.

Ginger's falling asleep. OMG this is the closest she's been to feather's since FEATHERGATE.

Finally the tree.

Now it needs some presents. Send me some presents.

Just kidding.

Let’s get back to building, shall we?

Tonight, high on the excitement of flipping the right wing over, I decided to get some more aluminum down from storage.

These two pieces are the Aileron Gap Fairing and the Flap Brace.

Part numbers shown for the right wing.

Turns out these have been in the garage for over a year now, so when I pulled off the blue vinyl, there was some residual…well…residue.

A little acetone fixed this right up.

I scuffed these up quickly (I’ll do this more completely when I’m about to prime) and got out the right aileron brackets. The top of the inboard bracket was interfering on my wing (like everyone else’s before me), so like them, I ground down the top corner a little with the scotchbrite wheel.

Here's the corner I ground down.

And clecoed in place.

The outboard bracket clecoed in place.

Here’s the flap brace, looking inboard.

I'll matchdrill both sides, but only rivet the brace to the spar now, the skins will come later.

The flange on the inboard most section is sitting a little funny, so tomorrow, before matchdrilling, I’ll see if I can’t straighten this out a little.

Crooked flange.

Flap brace looking from inboard to outboard.

Then, I clecoed on the aileron gap fairing.

With no trimming, look at how nicely everything lines up. Man, this is easy.

30 short minutes tonight, but it’s better than nothing.

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Constructed Wing Cradle

December 11, 2011

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Well, I needed something exciting to do on the airplane, so, instead of starting in on the right flap, I decided to work on the wing cradle.

Even though the right wing is the only one complete (well, kind of complete), flipping it over into a cradle will free up some room.

Let’s take a look at the intended final product.

Leading edge traces.

First up, I need two 3′ by 2′ end pieces.

Below, you can see I have one of the end pieces on my workbench with a couple leading edge traces. Since the spars are about 8″ wide, I used simple math (well, simple if you aren’t an engineer; I made it complicated) and left five inches from the edge, 8 inches for each spar, then 10 inches in the middle.

Leading edge traces.

After some master woodworking...

Then, I laid my other endpiece underneath that one, and marked the edges of the cutout so my spar reinforcement bars would fit well.

Done.

Per the plan, we need a little reinforcing at the top, and a 2×4 for the bottom.

Done and done.

Then, with a little more woodworking, I used my aileron bending brake and cut six two-foot-long angled support pieces, assembled pretty obviously per the plans and picture.

Whoa, this thing looks serious now.

With a little carpeting...

Then, I spent about an hour getting the right wing into the cradle all by my lonesome. I was extrememly methodical, and thought through long and hard about how I was going to do this.

Yes, I could have had a buddy over to do it in 5 minutes, but no, I had to make it difficult for myself.

Anyway, if you remember, my wings were supported by two pieces of angle supported by a 3/8″ bolt through the actual stand, and a threaded rod supporting the other end of the angle. The outboard side of the wing was bolted to the angle, so all I had to do was unattach the threaded rod portion, stand at the wing root, and rotate the wing. The outboard side pivoted around the wing stand bolt, and I was able to gently set the inboard side of the wing in the cradle as shown below.

Then, I moved to the outboard side to undo the last two bolts, and gently lower that side.

Easy peasy. (Next time, I’m getting a buddy to help.)

Before moving the stand back onto the MDF piece on the floor, I took the other spar off the stands, tipped each side of my stands up and took off the right wing stands.

Now both wings are a little closer to the center of the stall, giving me more room by the workbench, and the girlfriend a little more room with her car door. (That’s always a good thing.)

I know the garage is messy, but here's the right wing in the cradle.

One last shot.

Nice.

Time to get working on the lower skins. Well, let’s do the aileron gap fairing and flap brace first.

2.5 hours with all the construction and moving around.

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More Right Top Skin Riveting Prep

August 11, 2011

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Not much tonight. I put rivets in the remaining top skin holes and did some better inspection of the rivets we set a few days ago. All the rivets look great, but I’m less than perfectly content with some of my edges. The tank-top-skin seam has a really tiny step to it. I rolled the edge a little, but I probably could have gone a little more with it. Also, my very nice scarf joint turned out to not be perfectly flush either. It’s not anything I’m going to change, I’m just going to have to accept that I’m not going to win any awards.

Anyway, I put the rivets in and put a piece of tape over each one.

Rivets and tape.

Rivets and tape and rivets and tape and rivets and tape.

After 45 minutes of that, I grabbed my right outboard aileron bracket and decided to tackle the bad rivet and small gap.

Here’s the bad rivet. The shop head just barely started to split.

Yikes.

It also cause the part to separate a little.

This is not acceptable.

After drilling out the two closest rivets…

Whoa. That's weird.

Anyway, I got a small clamp out….

Better.

And re-set those two rivets.

Shop heads look much better, and now there is no gap

Since I had scuffed up the parts a little while riveting, I shot a little more primer on everything.

The blue tape is there to protect the bearing. Didn't want any paint on them.

1.0 hour today…pretty boring. Drilled two rivets out, but now I’m ready for Joe to come over and knock this wing out.

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Dimpled Right Upper Wing Skins

July 31, 2011

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Holy crap I got a lot done today. If you remember from yesterday, I forgot to attach a wire for the float fuel sender. Instead of ordering an appropriate sized wire, I used some of the only aircraft grade wire I had laying around, which was some 16 AWG. I know that is way too big (we’re just measuring a resistance), but it’ll work so I can install these tanks for the last time today.

Some people run two wires, but I checked the resistance through the tank, and I’m getting a nice solid reading from the tank itself, so here’s my one wire to the center conductor.

First official aircraft wiring. Done.

After reinstalling the tank, I held the wire to the negative lead and held the positive lead against a few different points on the tank.

All read between 38Ω and 240Ω or so, so I’m good.

Sweet. I don't have to unseal the tank to attach another wire to the sender body.

I’m flying through these skins right now. Pretty soon, I’ll have nothing left to do other than install the upper wing skins.

On tap for today is some dimpling and priming.

Here’s the inboard skin, ready for dimpling.

...on the nice vacuumed workbench.

Oh yeah, don’t forget your scarf joint. (A nice transition from the inboard skin to the outboard skin by the tank so there isn’t a big step.)

Looks good from this angle.

I also filed down the inboard side of the outer skin (the one I’m holding below).

Okay, this looks like it will work.

For some reason, you can see a little of the edge on the left side of the picture, but I didn’t notice this with my naked eye.

I’m very happy with it. It is a great transition from tank to skin.

I'm very happy with this.

After the scarf joint, I spent about 2.5 hours dimpling.

I've been using the male die on top with great success.

More dimpling.

After a little prep, I shot these with self-etching primer.

I sprayed them outside, then moved it back inside to dry.

For the outboard skin, I actually hung it inside-out on the wing.

More priming glory.

The wingwalk reinforcement skin.

And finally, the exterior side of the inboard skin where it will underlap the outboard skin.

3.0 hours of dimpling fun. All I have to do now is deburr and dimple the skeleton. Then, skin riveting!

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