Wings | Andrew's RV-7 Build Log

Prepped and Primed First Wing Rib

January 6, 2011

Well, since my tool order from Cleveland finally showed up, I decided it was time to jump into rib prep full speed ahead. Because I have already finished most of the edges, fluted and bent the flanges to 90°, I really just needed to prep the lightening holes (which I couldn’t get to with the 6″ scotchbrite wheel) and use some emery cloth to get the smaller crevices.

Here’s the tool order. Along with 75 1/8″ clecos, I got 100 more 3/32″ clecos, a 2″ scothbrite wheel, the mandrel for that wheel, and some #41 and #19 drill bits.

I love new, shiny clecos.

I put a washer on the top of the mandrel and then screwed down the wheel.

Crap, not enough threads.

Took it apart, removed the upper washer, then assembled it again.

I'm showing one thread, but that's okay.

In order to start taking apart the wing to get at the ribs for prepping and priming, I needed to unjack the rear spar, which means I have to remove the leading edges, which are clecoed to the main spar before allowing the weight of the wing to bend everything.

Here are the leading edges on the workbench.

I guess I snapped a picture of my 320 grit emery cloth. (This isn’t really cloth, it’s more of belt-sanding sandpaper. It works, though.)

320 grit from NAPA.

I chucked the 2″ wheel in the drill press and started cutting grooves in it (with the ribs I was deburring).

That groove is from one rib's lightening holes. I'm going to need more scotchbrite wheels.

After completely edge-finishing the rib, including flossing the little crevices with the emory cloth, I dimpled the one hole in the rib that is underneath the rear spar flange, which also needs to be dimpled to accept a dimple in the skin. Here’s the right rear spar, lower flange hole that I dimpled.

Dimple!

Then, I primed the rib.

Still wet from primer...

The next morning, it was dry, and I snapped another picture.

Nice...

This took me about an hour, but I spent a good 20 minutes getting organized first. I won’t prime each rib individually, but I’ll probably do them in groups of 5 or so to break up the monotany. Tthere are 28 total main ribs…I’m not even going to think about the leading edge and tank ribs yet).

That one rib looks good, though. I need to think about ordering some snap-bushings for the holes in the forward edge.

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Leave a Comment » | Wings | Tagged: Deburring, dimple, edge finishing, prep, Priming, Rib | Permalink
Posted by Andrew

Stall Warning Access Panel Work

January 4, 2011

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Well, I was able to spend a short half hour in the garage tonight. Last time, I ended up working on the access panel for the stall warning vane. I figured getting that prepped, primed, and nutplated would be a nice short task completion.

Here's the doubler, dimpled (for #6 screws) and scuffed after running the edges through the scotchbrite wheel.

I finished the edges of the cover, too, and dimpled for the #6 screws. The other side of this plate is devinyled and scuffed, but I’m leaving the vinyl on this (the potentially polishable) side.

Ready for priming.

See, I told you the other side was scuffed.

Primed!

While the primer was drying, I did a little edge finishing of the stall warning vane mini-rib.

Scuffed, but I still need to edge finish in all those crevices.

After the primer dried on the doubler, I set some NAS (oops) rivets with some dimpled nutplates.

20 rivets.

I didn't tighten these down at all, just threaded them into place.

Of course, I had to cleco tonight's work back into the leading edge.

A half hour, 20 rivets.

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Leave a Comment » | Wings | Tagged: #6, Deburr, dimple, edge finish, Rib, Scotchbrite, Stall Warning, Vane | Permalink
Posted by Andrew

Mucho Leading Edge Work

January 3, 2011

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Warning: This is a long post with lots of pictures. I’ll try to keep commentary to a minimum. (Oh, and I just took the pups for a run outside, and it was cold, so please excuse the typos…my fingers are still a little frozen.)

Well, today was a day off for me (New Year’s Day observed) where everyone else had to go to work, so I got a ton of work (on the airplane!) done. It was really cold last night (and today on our run…brrr), so as soon as I was ready to get out into the garage to work, I turned on my portable heater and turned right back around to go inside.

Hmm. I guess I can devinyl some leading edge skins while the garage heats up and I keep warm with coffee.

Here's the right leading edge.

Right leading edge upside down.

More right leading edge

Left leading edge, upside down. (That hole is the stall warning vane access panel. More about that later.)

Left leading edge again. (That small strip of devinyled leading edge on the left side of the picture is the stall warning vane rib attachment. Again...more later.)

That was about an hour of devinyling, so when I took my leading edge skins outside, it was not too bad temperature-wise. Thanks portable heater!

Note: I am working a little out of order. Technically, I should be prepping the main ribs for priming, then riveting those ribs to the spars, then setting the wing stand up, and then adding the leading edge. Since I’m waiting on some scotchbrite wheels for the rib prep part, I’m jumping ahead to the leading edge stuff.

Here, I’ve got all of the right leading edge ribs (except the inboard, undrilled rib) clecoed into the leading edge skin. Many people have trouble here, but if you follow the directions (which I kind of did), you start from the front end of the rib, top and bottom, and then you are okay from there. The biggest trick I found was to push the rib forward (towards the nose) as you are maneuvering the rib into place. I have long arms, so I could see the holes line up from the back, then reach around and stick a cleco in.

I like my modular leading edge/tank cradle. (No comments about my split triangular piece of MDF, please.)

Anyway, then I put the leading edge on the spar, and stood back in amazement. (Amazement at the size of the assembly, and that all the holes freakin’ line up! I know this is a prepunched kit, but still, everything just always lines up. Thank you Vans!)

Nice.

The dogs must have sensed my excitement…they came out to see what was happening.

Ginger: "Shouldn't you have prepped and primed all of these ribs first?"

Jack (tentatively): "Whoa, that leading edge looks good, but I'm going to stay here...the concrete is cold on my paws."

After playing for a few minutes, they went back inside (it turns out they came out to ask me to turn on the gas fireplace….okay, okay, I will).

On to the left leading edge.

This is an awesome sight. It finally looks like I'm building an airplane in here.

After setting both leading edges on the spar (and securing them from beneath with some #30 clecos through the main spar), I noticed that the spar really needs to be straight and level to proceed, even though it’s not fully assembled yet.

So, even though I know I’m going to take this all down soon, I went ahead and leveled the spar using the trusty (and calibrate-able) iPhone app from Stanley.

I couldn't decide whether negative or positive 0.0 was better, so I left it with negative. My wing stand mechanism sure made this easy. Every 1/4 turn of my adjustment nuts was about 0.1° change. Easy to dial in.

Then, I needed to address the spar bowing in the middle from the weight of all the components. (Once the skins are on the wings, they provide that support, but until they are, there is no (what I’ll call) lateral rigidity.

A variation on a (wing stand) theme. a threaded rod between two 2"x4" blocks.

I thought about this a long time ago, and I didn't know if it would work. It worked great. I know it's not permanent right now, but still, very elegant setup, if I do say so myself.

Oh yeah, I snagged this picture to elaborate on the reason for the larger angle off the outboard rib from the other day. See how the skin overlaps the edge of the rib and spar? I won’t have to notch my support angle to accommodate the skin now.

With the larger angle, there is plenty of room for the skin overhangs.

Okay, time to remove the spar sag.

I tied a piece of string between the top edge of two clecos (actually, it didn’t need a knot…the cleco clamped the string enough).

It's about 1-hole-diameter distance above the hole.

Same on the other side.

Before removing the sag, you can see how much bow there is (look at the row of primed countersinks).

There's about a 1/2-3/4" of bow in the middle of the spar.

A few cranks of my adjustable homemade jack, and the middle of the spar shows the same distance with the string. This was equally as easy to dial in.

Nice and level. (Ooh, that "flush" rivet on that nutplate isn't so flush. I might need a rivet shaver...)

Then, with everything level, I clecoed the leading edge skins to the spar.

Leading edge skins now clecoed to the spar.

Now I can move on to the inboard leading edge rib. It comes undrilled, so first thing, I kind of held it in place and made little marks where the holes were going to go.

You can see my very faint marks.

Then, back to the workbench for fluting (between the hole locations) and flange bending (to 90°).

I had to pretty aggressively flute in some places. Some of these ribs are better than others.

Okay now I need the…what is it?

W-423 Joint Plate.

Okay where is it. I’m sure there are two of them, one for each wing…

[searching shop storage …hmmm…and the airplane room upstairs…hmm…]

Grrr. Where did they go?

Upon closer inspection of the plans…

Oh.

That was easy.

I marked my half inch line and then pondered how I was going to fit this round (straight) peg into the square (rounded) hole.

This goes in there.

[Many loud, frustrated grunting noises…]

Ahh, there we go.

Then, after careful measuring, checking, drilling, remeasuring, and rechecking, I had the right joint plate and inboard rib drilled.

That was annoying. There was no good way to clamp everything, so everytime I drilled a hole, the rib shifted on the other side.

This one turned out pretty good. 11/16″ all around. I repeated that exercise on the left wing.

I don't have the perscribed 11/16" flange that I am supposed to on the left wing for the tank nutplates because everything moved around a little.

It’s only 1/16″ short in some places. I’m assuming I can make it work with 10/16″, but if I can’t, I’ll just redrill a new joint plate.

Anyway, I was staring at the opening for the stall warning vane, so I got curious and fished out the (separately packed…not really part of the original wing kit) stall warning components. They have this doubler that fits in this hole, with a couple locator tabs (in case you are modifying an existing leading edge that was not prepunched with this access hole). Since mine already has the hole, I snipped off the tabs.

These directions are crazy complicated, but they ended up being mainly for retrofit into an existing wing. For new construction, it's pretty straightforward.

I definitely need the access plate doubler and cover no matter what, but I did give some thought to whether I am going to install the stall warning vane.

I am planning on using the Dynon AOA vane, which will give me good stall warning (I believe it is calibrated during some demonstrated stalls for the highest AOA seen during stall for any flap configuration). For awhile, I kept thinking that I won’t need the Van’s vane (and I was a little miffed that they cut a big hole in my leading edge!), but then the CFI in me woke up and thought of a few things.

Every once in awhile during a rotation or flare, I might get a little chirp of the stall warning. Everyone does, and it can’t hurt to have a small reminder, separate and therefore redundant from the Dynon Air Data Computers (ADCs…wait, I think dynon calls them ADAHRS…or air data, attitude and heading reference system) during slow speed maneuvering. The Dynon is based on pressure differential (between the front and the angled top of the pitot probe), and the other is based on direction of relative wind (the vane just lifts up and compresses a microswitch when the relative wind pushes up on it).

I’m going to go ahead and install all of the provisions for both. It will be pretty easy to get everything installed, and just leave the little vane out if I don’t want it in the end, but I have to fill all the rivet holes anyway, might as well not rule out any future decision changes.

I’ll probably install both; you can’t be too aware of low speeds, and frankly, it will probably help resale to have the more traditional stall warning.

Anyway, I drilled the doubler plate to the leading edge.

Then, I found the leading edge vane support rib. They come as a pair of two; one for the RV-9, and one for the RV-7,8. It was obviously while holding it up to one of the leading edge ribs that the one with the sticker on it is the correct one.

So I wouldn’t forget, I tossed the other one in my scrap pile.

The one on the right is the one for the RV-7 (and -8).

Whew. Good day. I’ve made good progress in the last few days. Tomorrow, back to work, but hopefully I can keep this up.

Oh, and for the record, I hardly had enough 3/32″ (silver) clecos to do both leading edges at the same time. I just ordered 100 more, but I am going to need way more that that to keep working on both wings at the same time. This might be a good time to work on one wing at a time…or break down and order the 500 or so that Vans suggests.

3.5 hours.

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3 Comments | Wings | Tagged: AOA, devinyling, Drilling, Dynon, Leading edge, leveling, skins, spar, Stall Warning, threaded rod, Wing | Permalink
Posted by Andrew

Leading Edge Rib-to-Spar Drilling

January 2, 2011

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Well, after a quick run to Lowe’s to pick up a few more pieces of shoe molding for the family room (see my first floor wood floors page and today’s update here), I finished the family room and then headed out to the garage for an awesome two hours worth of building.

Why awesome?

First of all, I picked up these awesome tools for the project. I needed some good 3″ clamps for the spars (where they will attach to the wing stands) and a couple of plumb bobs to help measure twist. Also, I’ve been using my plastic triangle from 7th grade geometry as a square…it’s about time I got a real square.

Tools! Tools! Tools!

Then, I got out the jigsaw with a medium metal cutting blade and cut a couple 5″ pieces of 1.5″ angle. I attached these angles to the outboard ribs, which will allow the ribs to be attached to the wing stands.

I used 1/4" bolts instead of 3/16". I hope I don't die. (Also, don't pay attention to my edge distances...)

Here’s a good shot of what I’m trying to accomplish. The skins will overhang (to the right in this picture) the spar by about an inch from the last set of holes in the spar. I used the 1.5″ angle so I have adequate spacing (don’t have to notch my support angle to accommodate the skins).

This will work great.

Okay, next up, rib preparation. Here are 10 of the 12 leading edge ribs (these 10 have the prepunched holes).

Leading edge ribs.

After spending about an hour deburring edges with the scotchbrite wheel, straightening the flanges to 90° and then fluting between holes to make sure the holes are straight, I numbered the ribs for each of the wings and then got to match-drilling.

The only difficult parts here are that a couple of the W-709 ribs have holes where they don’t need them and don’t have holes where they do need them. The picture below illustrates.

Ignore the row of holes that has a cleco in it already; these are the main rib attach holes. See how the three middle holes leading edge rib lines up nicely with the prepunched holes in the spar? Those are easy to matchdrill to final size.

The outer two holes on the rib get "abandoned" while the two outer holes in the spar are used to backdrill new holes into the rib.

Here, I am using the holes in the spar to drill the new holes in the rib.

Matchdrilling using the spar.

I threw a couple clecos into the new holes. Now there are 5 attach holes, and 2 abandoned holes (you can see them on the outside).

There are 4 total leading edge ribs that get this treatment. It's easy to tell which ones need it as you assemble the leading edge.

Then, I spent another half hour making sure all of the rib-to-main-spar holes were drilled. Now, they are ready for disassembly, deburring, prep for priming, priming, and assembly.

Oh wait. I still have to drill all the rib to rear-spar holes. I’ll do that tomorrow.

Before shutting down for the night, I snapped a picture of the two wings in the stands.

It's awesome to be at a point where I can see two big wings in the garage.

A half hour of attaching the outboard ribs to the wing stands, then 1 hour straightening and fluting rib flanges, then another half hour drilling ribs to the main spar.

I’m waiting on a 2-inch scotchbrite wheel from Cleveland Tools, so tomorrow I’ll drill all the main ribs to the rear spar and then I’ll find something else to do.

2.0 hours of big skeleton work.

Oh, and we shot this video the other day of the pups howling at a fire engine. I won’t ever not find this hilarious.

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Leave a Comment » | Wings | Tagged: Drilling, flange straightening, fluting, main spar, Ribs, Wing | Permalink
Posted by Andrew

Fluting and Straightening Left Wing Ribs

January 1, 2011

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Well, today was kind of boring. Between installing the toilet back into the powder room and sitting on my butt watching football, I managed to motivate enough to go do some fluting and flange-straightening on the left wing ribs.

I didn’t hang the outboard rib yet (still have to attach a 5″ piece of angle to help support the outboard edge), but here are the first 4 (of 14) ribs done.

I'm really liking this stand.

7 of 14 ribs done and hung.

All done.

Next up is matchdrilling the main ribs, then getting the leading edge ribs prepped, assembled on the spars, and matchdrilled. Then (because I’m working a little out of order), I’ll take all the ribs off and prep them for priming before starting to rivet the skeleton together.

A boring, but important hour of work today.

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Leave a Comment » | Wings | Tagged: fluting, prep, Ribs, straightening, Wing | Permalink
Posted by Andrew

Finished Building Wing Stands

December 30, 2010

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After some work on the house this morning (trim up in family room, prepping the powder room for paint), the girlfriend and I had lunch and then I spent the afternoon in the garage. I could have kept working on the house, but I really wanted to get the wing stands finished.

First thing, I reorganized the garage to make room for the wing stands. Then, I started gathering all of the necessary hardware. Yesterday, I went to the hardware store and started counting out individual pieces that I would need. I quickly realized that I could always use a good inventory of 1/4″ and 3/8″ nuts, bolts, and washers, so I bought the contractor packs.

After all was said and done, I hardly used any of these packs, but I'll have good inventory for the future.

I also bought two 4′ lengths of 1/8″ aluminum angle (2″x2″) as well as a 3′ pieces of 1/8″ aluminum angle (1.5″x1.5″). I did this because I’m going to have 4 main supports for the front spars (2″x2″ angle), some supports for the rear spars (2″x2″ angle), and some smaller angle (1.5″x1.5″) to make the truss system I’m going to use.

(Sidebar: The whole time I was working today I was replaying the mechanical engineering class I took in college about linkages. Read a quick one-page summary of the class at http://en.wikipedia.org/wiki/Linkage_(mechanical). Pretty interesting stuff.)

I know a lot of people have made a lot of different kinds of wing stands, but I saw Ethan’s and decided I wasn’t going to re-invent the wheel. It’s a good, adjustable system. You can find a couple pictures of his stands here and here.

Okay, let’s start making some aluminum shavings…

My 4 main supports, and my 8 small brackets.

I then drilled the holes in the brackets. I’m using 3/8″ threaded rod, which is probably overkill, but I stood in the hardware store with the 1/4″ stuff and it took a considerable force to make it bend (buckling). I picked up the 3/8″ rod and it was rock solid. I figured for a few more cents per rod, I’d rather overdo it. Anyway, the brackets on the right will get the 3/8″ threaded rod and a 3/8″ bolt through the main stand post. The brackets on the left will get the 3/8″ threaded rod and a 1/4″ bolt that will go through the 2″x2″ angle (the smaller bolt for the smaller head so I won’t have any interference). You’ll see.

Holes drilled in the brackets.

Then, I made matching pairs of left and right supports.

(The bigger hole goes through the main post, the smaller hole is for the bolt that will hold the bracket on).

Here are the brackets attached.

Then, I threaded in the 3/8" rod.

Before I can go any further, I need to make sure the spar will be level when they are hung. Since the garage is sloped, I can’t just drill holes 2 inches from the top of each post. (For the record, I think I could build it that way, because the real issue is wing twist, which could still be fixed if the spar wasn’t level, but I would rather have the wing level.)

Me using the laser-level.

This thing is awesome (it’s my girlfriend’s). I held it up against one support and moved it up or down until the level line across the garage was right on the top edge of the post (the picture below shows me about 1/2″ too low). When the level line was even with the very top edge, I marked a line under the laser leveler (it has a little hole for marking), and then I measured down from that line (and the top of the other post) 2 inches to mark a spot for drilling.

Using the laser leveler.

After that, I drilled a 3/8″ hole and measured down 18″ for the bracket hole and drilled another 4 holes.

Then, I assembled all the hardware and…

TADA!!!

Wing stands!!

Here's a closeup of one set.

And an even bigger close-up of the mechanism. Since most of the force will be down, I kept the threaded rod long and mounted the post bracket 18" below the main bracket.

Here's the upper adjustment mechanism.

And the lower adjustment mechanism. Thank you Ethan.

Then, I had to put the spars on the stands. (Making sure to carefully clamp each side.)

Wuhoo! Wing stands.

I need to add some screws into the 45° wooden supports, and tighten up all the hardware. I’ll also probably cut the carpet out from under the stand bases and use some construction adhesive to glue those bases down once I know their final locations.

Still a very good day in the shop, and now the shop is clean and organized for the wing activities that will hopefully take me through summer 2011.

All in all, I think I worked about 3.5 hours on the stands today. Not bad.

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Posted by Andrew

Finished Left Tiedown

December 29, 2010

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Well, with a full week at home this week to work on the airplane, of course it was Wednesday by the time I actually got out to the garage. Too many other things going on.

I was determined, however, to make some real progress, and I think I did okay.

I scoured around for my right tiedown and then pulled out the raw parts for the left side.

Here's the left tiedown stock and the two spacers that I cut while I was working on the right side.

Visit from the puppies (no, the toilet isn't hooked up...but how cool would that be?!).

After getting everything set and lining up the tiedown per the plans (oh man, I used to be so good at documenting these little steps), I started match-drilling.

The plans say to drill these to 3/16″, but I went ahead and drilled them to #12, which I think is a little bigger, but the AN3-_ bolts don’t fit in the 3/16″ holes, and they fit perfectly in the #12.

The bolt in the lower right hole is the one from the single (of 8) holes they tell you to drill in advance. You use a bolt to line up that hole and then picot the whole assembly around that point to 90° of the spar. Then matchdrill.

After all 8 holes are drilled to size…

Which one of these is not like the other?

Flipping the spar over, you can see I didn’t do to badly with the edge distances on the spacers.

It looks a little weird with the tape offset, but I did that to allow for the first bolt.

On the right tiedown, I drilled the lightening holes first. Here, I figured I’d do them in the other order.

Ready for lightening holes...just marking the center.

1-inch hole saw....looks pretty centered to me.

This time, I didn't use any lubrication, and it seemed to do a lot better. Hmm.

After countersinking the nutplate holes for the flush rivets.

And finally, to priming before assembly.

I think the is the second side.

I started putting everything back together and got the squeezer out.

(I like getting the squeezer out.)

The one on the right is the left tiedown.

8 beautiful rivets.

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Posted by Andrew

Finished Left Rear Spar

December 12, 2010

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Well, I know I’ve been bombarding you with new posts lately (not!), but I did get a fair amount done today. As you can tell from the title of the post, I finished the left rear spar.

More importantly, I made an investment to my health this week.

I present to you…(triumphant music)…a heater.

Ta-da!

This is a pretty sweet heater. It’s small, only cost $20, and by no means will it heat the garage, BUT, the garage is no longer (literally) freezing, and I can work in front of the workbench comfortably for a whole day. It will provide me with two heat settings and has a little fan in it. I set it in the corner of the workbench (as pictured above), and after about 5 minutes, I have to turn it down to the low setting. After about ten minutes, it is pretty comfortable where I’m standing in front of my workbench. And, now that I think about it, it does take the chill off the rest of the garage. Even for the one day I’ve really used it while I was finishing the floors, it has totally earned its cost back.

Okay, back to the airplane. I finally found my stepdrill, and made a couple holes in my W-707E.

Step-drill to the rescue. Had I planned this a little better, I would have done three smaller holes.

I clecoed W-707E back onto the rear spar and flipped it over to use the dremel to clean out the rest of the aileron pushrod hole.

I'm about to flip the spar over and use the dremel to clean up the hole.

I'm not totally done here, but you get the idea.

After that, I moved on to dimpling the reinforcement plates where I won’t be able to dimple them later.

4 #30 dimples along the left (outboard) edge, and #40 dimples along the top flange.

I also dimpled the flange of the rear spar where the reinforcement plates will go.

Then, after a little more scuffing and cleaning, I shot primer on the spar.

I love this color. Makes me happy.

And the left W-707E and W-707F.

After a couple hours inside while the primer dried, I came back out and studied the rivet callouts.

Looks like I can set 7 rivets here right now. All size "square," which is AN470AD4-8.

5 of the 7 set. Nice shop heads, huh?

I moved along the reinforcement fork, using clecos as indicators not to rivet certain holes yet.

I chose to put the shop heads on the aft side of the rivet (these are manufactured heads). I like shop heads, and it makes inspection easier.

Moving outboard, I studied the same callout for the middle reinforcement plate, or W-707E.

Looks like I can set five here, of size "upside down triangle," which are AN470AD4-4.

Manufactured heads

Shop heads.

And repeat with the outboard reinforcement plate.

6 here, I think. More upside-down triangles.

Manufactured heads.

Shop heads.

Then, I couldn’t help but grab the right spar and put them both up on the workbench.

It feels good to have both rear spars done.

Look at the difference in paint color. Left spar (just finished) is on the right.

More difference in paint color.

Anyway, all the rivets were symmetrical from right side to left side, which doesn’t mean I’m correct, it just means that if I did make any mistakes, I made them twice!

Now, all that’s left on the spars is to finish up the left tiedown. Then, I really need to make some wing stands and finish up some rib deburring.

Tonight was a good night. 56 rivets, and it feels really good to get something big put together.

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Onward and upward!

Leave a Comment » | Wings | Tagged: Deburr, drill, heater, manufactured head, plate, prime, reinforcement, Rivet, shop head, spar | Permalink
Posted by Andrew