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.


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.


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.


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….


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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Deburred Right Upper Outboard Wing Skin, Right Leading Edge Rivets

July 29, 2011

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Tonight was only mildly more exciting than last night!

After taking the right upper outboard skin inside to deburr and scuff (AND VACUUM THE LITTLE ALUMINUM SHAVINGS OFF THE COUNTER, SORRY GIRLFRIEND!!!), I brought it back outside, and stored it (like the inboard skin), upside down (or inside out) on the left wing.

The two upper right wing skins, stored on the left wing for now.

For some reason I am paranoid about alignment, so I clecoed the right lower skins in place, although only 25%. I’ll come back with more clecos when I start riveting to make sure things are perfect.

The lower side of the right wing.

After looking at the clock, I figured I had about 30 more minutes.

Time to look at getting the right leading edge riveted to the spar (I had done the skin rivets, albeit out of order, a few days ago.)

From Brad Oliver’s site:

Oh boy, what a night. I riveted the left leading edge to the spar tonight. I used blind rivets to do this job, MSP-42, -43 and -44 rivets from Aircraft Spruce to be exact, but that isn’t the end of the controversy. I riveted (pulled) these rivets from inside the leading edge. Why use blind rivets? Why from the inside? Well, first of all, in my opinion certain blind rivets blind rivets are completely acceptable here. Van’s has said to many builders that the use of LP4-x rivets is acceptable here, and the LP4s are pretty soft as rivets go. I decided to step it up a bit and use MSP rivets here. They have a Monel (M) head, with a steel shaft (S), and a protruding head (P), and by my calculations are very similar in strength to solid rivets. I am likely to catch flack for that statement, but do your own calculations and see for yourself. Don’t take my word for it, and I am not recommending this method, only documenting what I did.

Why use blind rivets here in the first place? Because riveting the LE ribs to the spar involves grinding down a rivet set and you need two people for the job. These certainly aren’t big issues, but I wanted a easy method I could do myself.

Why from the inside? That one is easy, I wanted the factory head of the rivet to be on the thinner material (aft flange of rib). This was slightly painful, but I am proof that it can done. I also did this because even with the face of my cheap-o rivet puller ground down, I was having a hard time getting the puller on the shaft of the rivets due to their close proximity to the aft rib webs.

From Mike Bullock’s site:

No way to squeeze them. You could buck and shoot them, but you have basically no room to get a rivet set onto these rivets with the rib interference. The only purpose for these rivets are to keep the spar from bluckling. The way I see it, the chance of that is NIL, and there is a main rib set right next to each leading edge rib with the proper rivets in it. It doesn’t say it in the instructions, but builders have been told by Van’s to use LP4-3 blind rivets here. I did one better and used Cherry MSP-4? rivets. I bought a bunch of them from Spruce in the MSP-42, 43 and 44 sizes. They are very comperable to solid rivets.

I had some MSP-42 rivets in stock, so I grabbed 5 of them to try it out.

Once I got the ribs pulled into alignment, it worked great.

See? Great.

And any day you weren’t planning on contributing to your rivet total but you do…it’s a good day.

1.0 hour. 5 rivets. I’ll do the rest of the leading edge tomorrow. Also, someone PLEASE remind me to buy a balloon and a bicycle tire pump to test this darn right tank. It’s been two weeks, so the pro-seal better be dry.

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Started Deburring and Dimpling Right Wing Ribs

July 28, 2011

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Well, not much tonight, except a complete lack of motivation. I move the right upper inboard wing skin over to the left wing (just to hang there) while I started deburring and dimpling the right wing ribs.

I decided to only deburr and dimple the upper side of the ribs. I’m going to leave the lower side as-is so I can 50% cleco the lower skin (when able) to the skeleton while riveting the upper skin in place.

Action shot of me dimpling the ribs.

I was planning to be out in the garage for an hour and a half, but my boredom got the best of me and I quit after a (hot) half hour.

I told you it wasn’t exciting.

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Finished Drilling Right Top Skins, Started Deburring

July 25, 2011

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So, while today is probably kind of boring for you…it’s exciting for me.

Why is it exciting for me? you ask…

Because I’m starting on the wing skins, and that means that coming up is some wing skin riveting, and that means that pretty soon, I’m going to have WINGS in my garage.

(Oh, also, I tricked the girlfriend into putting in some manual labor on the airplane. Ha. I’m so sneaky.)

First thing’s first. I ordered two new camera batteries. The one in the camera taking the picture says “12/09.” (Thanks, sister! Still one of the most used Christmas presents of all time! The one that replaced was the original from my Aunt Jan way back in 2002. Whoa.)

Now I'll never be out of camera go-juice.

Okay, let’s get on with it. A few days ago, I was clecoing on the top skins and realized that I hadn’t finished matchdrilling them. I think I only got half of them done. (I’ll go check my entries from then…)

So, back to 50% clecoed, and out came the air drill.

Okay, let's get to drilling.

After a loud 30 minutes of match drilling (“making loud noises”), I brought the wingwalk doubler and inboard top skin into the kitchen for some deburring and scuffing.

In the middle of deburring and scuffing the right wingwalk doubler.

After mucho mucho more cramping fingers minutes, I had some deburred and scuffed inboard wing skins.

Interior side...

...and exterior side.

Next up for these will be to dimple, then prime, then rivet to the wing (after prepping the corresponding ribs).

Before that, though, let’s get the outboard top skin done.

1.0 hour.

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Right Float Sender, Riveted Leading Edge to Spar

July 23, 2011

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Guess what? I worked on the airplane today, so the observant of you should realize that I am NOT on my way to OSH. Boo.

No use worrying about the spilled milk, though. More time for me to work on the airplane.

I need to leak test the right tank, but first, I have to finish sealing it up completely. Last post, I got everything sealed except for the float sender. Here’s the plans shot showing the sender, but it’s showing it mounted to the access plate. Mine will be the same dimensions, but entering from the rear of the tank in the second bay.

A couple 90° bends, and I'll be cooking with gas.

That was easy.

To install in the sender, you line up the plastic piece with the slot in the metal housing, and slide the float wire in.

Can't get any easier than that.

Now, let’s clean up and get this thing sealed in there.

Five #8 screws after swishing in some MEK.

After cleaning up a whole bunch, I put the rubber gasket in place with some sealant (couldn’t decide if I needed some or not), then put the float in, then more sealant around the edges, and some sealant for the screws.

Looks good to me.

I retested the sender and noticed 240 Ohms to 80 Ohms (I think I saw something lower before). That’s okay, my EFIS (Electronic Flight Information System) will calibrate the range of fuel levels based on resistance later.

Okay, that was about a half hour, and there are plenty of hours left in the day, so let’s move on. I think the next thing on the docket is to get the leading edge on the spar permanently. I have the leading edge landing light installed, and the tiendown bracket is good to go.

A changing of the plans picture…to the wing rivets and skins page.

Always fun to change plans.

After a few long minutes of getting the spar holes countersunk, I rubbed the scotchbrite pad over the length of the flange, cleaned up with MEK, then taped off to get some primer on there.

Ready for primer.

Sorry the light kind of precludes the primer from showing.

Okay, before I just start riveting the leading edge to the spar, I want to make sure everything lines up again. So, I want to put the tank on the spar, and the opposite skin from where I’m working.

Before I can get the tank on, I need to grab some nutplate for the inboard tank z-brackets.

Looks like AD3-4 and K1000-3 nutplates.

Here they are.

Done. I couldn't countersink very well along the spar bars, so I went a little light and used oops rivets on the very top and bottom (right and left here) holes.

Then I grabbed the outboard lower skin, and got it clecoed on.

Here's just the leading edge clecoed.

Then, I grabbed the tank and put screws in every 5th hole.

And a screw in every hole along the tank/leading edge joint. Everything lines up great and looks awesome.

I told you it looks awesome.

With the leading edge 50% clecoed, I decided it was finally time to show the FAA I’m really building this airplane. Sorry this awesome picture of a pre-squeezed rivet blocked the shot.

My visor says "Foxy's" on it. Anyone? Oh, and that rivet size looks appropriate, let's get to squeezing.

After 65 rivet squeezings, I had the upper leading edge skin riveted to the spar.

The leading edge looks so cool with no clecos in it.

After 65 more rivet squeezings, I had the lower leading edge skin riveted to the spar.

Oh man, I'm so excited.

GOOD DAY IN THE SHOP, high fives all around.

So….0.5 hours toward the tank. 2.5 hours toward the wings.

6 rivets for the spar nutplates, and 65 rivets each on the top and bottom of the leading edge. That makes 136.


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