Right Tank Inboard Rib Work

June 5, 2011

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After another full weekend of housework, errands, etc., I managed to fit in some work on the right tank’s inboard rib.

First thing, I fished out some parts. Here, Vans has punched out three parts, T-407 and T-410.

Hmm...where are my snips?

I decided to pull both assemblies(?) out and get them all deburred at the same time.

Here are the two access hole doubler rings and four rib reinforcement plates after deburring.

I put two of the reinforcements and one of the rings away until needing them on the other tank.

Then, I took one of the rings, centered it over the stiffener bump on the inboard rib, and used a straightedge to find the center of the circle.

"x" marks the spot.

I know I’m not really working on the left tank right now, but  I decided that since I KNOW the circle cutter is going to be a PITA, I’ll just go ahead and do the left rib, too.

I fished out the two end ribs for the left tank and marked them so I knew which is which.

L1 and L7.

Before mounting the ribs up on the drill press, I needed to find some wood backing. How’s this tank-rib-shaped piece right here?

Pepsi should pay me for the product placement.

Whoa. That sucked. It sucked so bad, I didn’t even take any pictures. Among other things, the circle cutter 1) wouldn’t stay in one diameter, 2) shook so badly I thought my workbench was going to fall over, 3) almost killed me twice.

But, I finally managed to get a decent looking hole.

Phew, I'm glad that's over.

See? Nice hole.

Oops, looks like the hole was a little big. No worries, edge distance for the rivets is just fine.

The hole in the rib is a little big...

After some more cursing, cheating death, and general unhappiness, I managed to get a better (appropriately sized) hole on the left inboard rib.

I think I'm going to throw away the fly cutter now. Stupid piece of crap.

Okay, I’m straying from the instructions a little here. Normally, they want you to take this access cover, hold it against the rib, and use the prepunched #19 holes to drill holes in the rib. Then, hold the stiffener right aligned with those holes, and drill the nutplate attach rivet holes. Clear?

Instead, I’m going to eyeball the clocking of the access cover (so the flat part doesn’t interfere with the indentation in the rib), then just use the stiffener ring for all the drilling. (I need to order a new access cover with no holes in it because I’m using flop tubes (don’t need the small hole), which means I need to move the float sender to the second bay (don’t need the large hole).)

You can see in this picture, the stiffener ring is laid in place, and it looks like the access cover is clocked correctly.

Access cover in the foreground, stiffener ring in the background.



Dimpled the rib, and countersunk the ring.

clecoed some K1000-8 nutplates in place.

Here’s where things got frustrating. Because I wasn’t paying attention, I just started riveting the nutplates in place.

Clearly I didn't countersink enough.

Another view. Yikes.

I drilled out six nutplates (didn’t enlarge any holes in the rib or stiffener), but couldn’t get the rivets out of the nutplates. They got THROWED AWAY!

Sorry, nutplates. You are going in the trash. It's not worth my time to fix you.

Okay, more countersinking, then try again. Still not deep enough? Ugh, more countersinking again, and finally, they were deep enough.

I got frustrated, so I stopped taking pictures. Sorry.

After much cursing and angry mumbling, I got all 24 rivets in for the 12 nutplates.

I had to drill out two more rivets because they were sitting a little proud. In the end though, I’m happy with the results.

These didn't need sealant because the access cover will be sealed over them.

A shop head shot.

24 rivets, 8 drilled out. (one third!? Ugh.)

2.0 glorious hours today.

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Started on Right Wing Tie-down Bracket

August 26, 2010

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Wuhoo, the new squeezer showed up!

After a few minutes of messing around with it, I grabbed the two K1000-4 nutplates and studied the plans carefully on which side of the spar they go. A quick hint (other than just reading the plans) is that the nutplates go on the side that couldn’t possibly need to be flush (in between the spar cap bars).

Anyway, here, I’ve countersunk for AN426AD3-6 rivets.

The two larger holes are examples of where Van's (or Phlogiston) buffed out some spar scratches with some scotchbrite.

Oh yeah, I also flipped the spar over and deburred (you can hardly see the deburring) the backside of the holes I drilled to #40.

The little silver rings are where I deburred. Because these will be totally covered by the nutplate and the shop head, I'm going to refrain from spot priming them.

I used the new squeezer to set my only 4 rivets today.

Don't these look pretty? (There are small rings around the rivet heads. That is from the cleco I used to hold the nutplate on while riveting the other side.) It seems weird the cleco made that little mark.

Moving on to the tie-down bracket. First thing, I need to fabricate the W-726 spacers from this 1.25″ wide angle stock. I’m supposed to cut 4 of them, 2 for each wing/tie-down).

Why is this one on the ground? Is it because the light is good for the camera? NO. It's because it is @&*!@ hot after cutting. Ask me how I know.

Here are the other three.

Each of these spacers should have a 1″ hole cut in the center for lightening (not lightning). Since all of my hole saws are in sizes other than 1″, I decided to grab the W-731 tie-down bracket and get to work on that.

Okay, the manual says to cut the tie-down bar to length from the AEX stock.

Okay (…searching plans…), looks like 7  15/32″. Of course, I measured 7  7/32″ marked, and almost cut before my gut told me something was wrong.

The bar is actually 7 16/32" ( or 7.5"), so I'm not going to cut them 1/32" when I'm sure the edge finishing on the scotchbrite wheel will be more than enough. (Also, it doesn't appear the extra 1/32" will interfere with the top or bottom skin at all.

I keep walking by this sticker and laughing. I thought I would share.

Translation: "If something doesn't fit right, you've royally screwed something up."

Okay, back to the tie-down. After marking and drilling the one (of four) holes for the spar in the bracket to 3/16″, I stuck an AN3-7A bolt in there and just eyeballed the alignment.

(You are supposed to drill just one, then fit the bolt through the whole assembly. Then, you flip the entire assembly over and matchdrill the tie-down bracket from the back.)

I was a little concerned that there was some overhang on the right side of the bracket. (I measured and drilled very, very carefully).

Looks like there is some overhang on the plans, too. Sweet.

Anyway, I stopped there because I can’t really matchdrill everything until I get the spacers placed behind the tie-down bracket, and I can’t really do that until I have the lightening holes drilled (the spacers will be riveted to the tie-down brackets in four places, which in turn hold some nutplates on).

Here are my spacers for the right tie-down bracket.

1 hour, 4 rivets.

Now, I need to find a good hole saw or fly cutter.

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More work on the Counterbalance Skin

July 20, 2010

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Things have been slow with the airplane recently, right? Well, after a few weeks of letting the garage slowly spiral into a mess of hall closet items (while I’m redoing the floors), saw dust (while I’m redoing the floors), and aluminum dust/shavings (I am working on the plane a little), I decided it was time to get things cleaned up. After an hour of cleaning and organization, I snapped this picture of a nice clean workbench and floor area. Doesn’t really do it justice, but something about a clean workbench makes me happy (notice how I am not showing you a picture of my second workbench!)

(Don't tell the girlfriend I had the vacuum cleaner up on the table going back and forth. It works pretty well, but I accept no blame if you try this at home.)

Okay, finally on to the project. My replacement E-713 came the other day. instead of trying to cleco it on to the already-dimpled skeleton and matchdrill, I am going to trust Vans’ pre-punches and just run a #40 bit through the appropriate holes before deburring and dimpling.

After that was complete, I taped the outside of the skin that I want to protect from primer and scuffed everything up.

Ready to prime...almost. I'm still waiting on a #10 dimple die from Avery. Should be here any day.

Because this part of the exterior side is under the main left elevator skin, I'm going to prime it. Those two smaller holes need to be drilled to #28 before dimpled for #6 screws.

After that, I grabbed my two trim tab horns, and deburred, scuffed, and dimpled the flange holes.

I still need to trim these down per the plans for the electric elevator trim, but I also haven't ordered my electric elevator trim kit yet.

Finally, I disassembled the trim tab to get a little start on that. Here’s the spar, deburred, scuffed, and dimpled on the bottom flange.

The top flange (on the left side of the picture) needs to be countersunk for the upper trim tab skin, because the hinge sits just below the flange, and can't accept a dimpled flange.

2 hours in the shop today, but only 1 hour counts as build time. Hooray clean shop!

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Started Prepping Left Elevator Skeleton

July 2, 2010

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Even though it was my day off, I spent the day trying not to get stung by bees (mowing the forest behind my fence) and meeting the girlfriend for food. After that, I managed to waste an hour or so installing a fan in the garage. Recently, it’s been brutal in the garage, so this morning, while I was walking around Lowe’s, I saw a small ceiling fan for $17. I couldn’t say no. It was harder to install than our nicer fans inside (no little quick-disconnect fan blades or anything), but in the end, it makes me cooler in the garage (double meaning intended).


Okay, back to work. I think you guys might have seen this picture yesterday, but here it is again…the little riblet I made after drilling.

Looks good. I am proud of this little guy.

Then, I moved over to the spar. These four holes get countersunk because they attach E-705, but the elevator horn has to sit over the rivets but still flush against the forward face of the web.

Beautiful countersinks.

While I had the countersink cage set up, I pulled the trim tab spar out of the elevator and started on it.

Countersink the top flange, dimple the bottom flange.

Aren't these countersinks nice?

After countersinking, both the tab spar and the left elevator main spar were scuffed (more), edge-finished, and then got a trip inside to the sink for a quick rinse before coming back outside to eventually get a coat of primer.

I'm getting close to riveting something, watch out!

Anyway, two very productive hours, and I think I can rivet some reinforcement plates tomorrow if I want. Wuhoo!

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Final Prep for Right Elevator

May 20, 2010

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Well, after deciding not to work out tonight (in favor of wine), I made it out to the garage pretty late for some final prep work before riveting the right elevator.

Tonight's build partner, 2004 Manyana (play on words) Crianza. A delicious tempranillo from Spain.

On with the building, you say? Fine.

One of the last real fabrication items I have left on the right elevator was enlarging the counterbalance skin dimples. To make a long story short, I don’t have #10 dimple dies, so I dimpled with #8, and then planned on using the AN507 screw head and a nut tightened down to enlarge the dimple enough for the screw to sit flush.

This did not work.

Okay, instead of waiting for a week for a $40 dimple die to arrive, let’s be creative.

Plan: matchdrill two holes in a block of wood, countersink the holes, then use a flush set to enlarge the dimples.

Here's my block of wood, later to be countersunk.

Well, I don’t really have any good pictures of my attempt, because that didn’t work either, and I was getting frustrated.

Finally, I told the girlfriend to come out and listen to me explain the problem. (I knew this would help me come up with a solution.)

Without even flinching. “Why don’t you use a bigger screw to make your dimple?”

my face = <deer in the headlights>

Of course! (Except I didn’t have a bigger countersunk crew, but it set me down the right path.)

This should work. (It's my punch set that came with my rivet gun.)

Setup recreated (I had a piece of tape on the skin to prevent marring.)

The hole on the left has been "enlarged." This worked great!

Okay, let’s move on. Next up, I needed to locally bevel the edges where the spar and tip rib are underneath the counterbalance rib (so the top skin doesn’t show the transition bulges. So I marked those, and also started thinking about how to attach these empennage tips. See the two undimpled holes to the right? Those are two (well, 4, two on top and two on bottom) tip attach points that will eventually be drilled, deburred, and dimpled. Might as well do it now so I don’t have to worry about deburring between riveted sheets.

Lining things up to wrap my head around this interface.

I flipped the pieces over and drilled them to #30.

The top two holes have been drilled and deburred, ready for dimpling.

After dimpling…this #6 screw fits pretty well. (Editorial note: I’m pretty locked in to attaching the elevator tips with screws. I know there is really no reason to take the tips off, but right now, I don’t want to commit to blind rivets.)

That #6 screw looks like it will fit pretty well.

Once the other side was done, I primed the interior (and taped off exterior) side of the counterbalance skin.

Priming. You can see the two #6 dimples at the top of the left side of the skin. (I'll do the rest later...the rest are all accessible in the future.)

While that dries…let’s devinyl!

Hooray for devinyling!

All done. (After using compressed air to blow the flaked primer off.)

Back to emp tip attachment, here are the #6 holes in the skin, dimpled the same way as the counterbalance skin.

Nice big dimples. (Whoa, I forgot to deburr that relief hole on the left there. Fixed after picture taken.)

Let’s get this thing clecoed together.

Those big dimples sit nicely in each other. Here you can see those two holes are the only holes that overlap.

Next, the manual has you rivet the following two holes (not accessible once the spar and tip ribs are in place).

Protected with tape, this rivets were set beautifully.

Without clecos, it's starting to look like an elevator.

Next, “loosely place” the counterbalance in the counterbalance skin and “partially” insert the screws.

The untrimmed (on purpose) counterweight in the counterbalance skin.

last, but not least, they have you insert the skeleton in the skin and cleco together.

Wuhoo! It really does look like an elevator!

Those screw heads are pretty flush. (They are not tight yet, so they'll sit a little better once I get them tightened down.)

A couple pictures of some of the interfaces.

Just behind the counterweight.

Trailing edge of the tip.

Inside corner of the counterbalance rib. (What's that stuff hanging from the top edge? I'll have to investigate later.)

Finally, the trailing edge of the inboard rib.

Ready to rivet!

One more shot.

1.5 hours, 4 flush rivets set.

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Riveted Right Elevator Skeleton

May 13, 2010

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Well, I’d been waiting for a couple days for an order from Aircraft Spruce to come in. I ordered a whole bunch (~60) #6 screws and nutplates to use to attach the emp tips, and added a couple 1/4″ nutplates to attach to the elevator counterbalance spars so I can add more weight later for fine elevator balancing.

Here’s the deal. When you initially balance the control surfaces (without paint), you can either leave them a little heavy (which some do), or balance them exactly. Given that I might leave my empennage polished, I thought I would go ahead and balance them perfectly for first flight, then rebalance (pronounced “add weight”) after paint. While the forward tooling hole in the counterbalance ribs would work for a straight up bolt and nut, I’d prefer a nutplate. Also, since the two counterbalance ribs are butted against eachother, I’d prefer to drill for the nutplate now, so I can deburr both sides of both surfaces.

(I wonder how people deburr holes drilled through two permanently attached skins. Maybe just the inside and outside of the two skins and not the middle two surfaces?)

Anyway, here’s the order.

screws and nutplates.

Both size #6 screws in their new home.

I'll definitely be able to tell the difference between the two sizes.

Here are the 1/4″ nutplates. I bought one-lug because I thought the second lug might interfere with the An509 screw and nut used to attach the elevator counterweight. I’ll point it out again later.

MK2000-4 nuplates.

Then, some of the smaller MK2000-06 nutplates. I bought these for some of the tight locations on the emp tips.

I forgot to take a picture of the 60-odd 2 leg nutplates.

Okay, now on to real work. Here I am trying to figure out how to get this thing in a place where I can drill it. I don’t have any 1/4″ clecos, so I had to just eyeball it. That was a bad idea.

After one of the #40 holes drilled.

Here's the second hole drilled. You can see I had to enlarge the tooling hole to much bigger than 1/4" because I am lame and didn't have a 1/4" cleco to located the two attach holes. Lame me.

After taking those apart and deburring the holes, I scuffed everything up, leaving only the four rear-most holes on the E-703 End Rib. Again, I use the rivet in the hole into the countersunk steel bar trick.

Ready to flush rivet to form this dimple.

I have a 5/8" flush set, which comes in handy in some places.

Both done.

After cleaning those two ribs, I set them aside to dry before priming. Then, I moved on to the WD-605-R-1 Elevator Horn.

Let's see. AN470AD4-4 rivets. I might have some of those.

A small smiley on the lower left rivet, but according to the diagrams, it is okay.

6 nice rivets. The shop heads are very nice.

See? Told you.

Then I shot the six on the other side of the horn.

I love this new tungsten bucking bar.

6 more down.

Back to the paint booth.

E-703 End Rib and E-704 Counterbalance Rib being primed.

And now, a big pictures shot of the elevator horn on the skeleton.

It's starting to look like an airplane.

Then, I deviated from the plans (like many builders here.) It is easier to attach the E-704 Counterbalance rib to the spar if you don’t rivet it to the E-703 End rib first. I managed to massacre the left head, and the flange on E-704 didn’t sit flat against the skin on the other side.

Whoa. Take it easy, Andrew.

I don't like how the flange isn't flush with the spar web here.

Time to get the drill out.

Drilled first with #40, then #30 through the head only.

Pop the heads off.

Then re-set. This is a little better.

But not perfect. I think it's going to be good enough. I'd rather see them sitting perfectly flat, but the area around the rivet is sitting where it should be. It's just around the edges of the flange that are standing off a little.

Here are the new manufactured heads. Much better.

There we go. What's next?

Okay, now I need to attach the E-704 to E-703. Wait a minute! There is no rivet callout for these.

I see one for E-703 to E-702 and for E-704 to E-702. Where is the E-704 to E-703 callout? Well, I guess I'll just use AN470AD4-4 rivets.


The three upper middle rivets are all horrible. I can't figure out why the gun is jumping around so much.

Anyway, before drilling those out, I wanted to get that nutplate riveted on. Same deal here, though. I couldn’t figure out how to cleco it on for riveting.

Here are the two NAS1097 rivets ready to go.

I ended up shooting both of these at once. (How cool is that?)

NAS1097-4 (I think they are -4s)

I held the bucking bar on the other side and used my finger to hold the nutplate firmly against the web of the rib.

Is this a good method? No. Did it work? Yes.

Anyway, in the above picture, you can see one of the three rivets that I botched. After drilling all three out, I reset 2 successfully, but messed up this one again.

Grrr. It didn't really bend over, but it kind of shifted to one side.

Drilled it out, then did the exact same thing. This is the third time I’ve drilled out a rivet on this hole.


I figured out that during the first try, I had bent the rib web a little, so the rivet was pre-inclined to lean. I took my tungsten bucking bar and my 5/8″ flush set (without a rivet) and got everything flattened out again. Next try, the rivet set well.

Top middle rivet. Much better.

Finally, an upside down picture of the right elevator skeleton.

Tomorrow, I'll get back to work on the skin. Maybe this weekend I'll have an elevator!

2 hours, 26 rivets. 5 drilled out (3 of those was one hole!)

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Primed E-709 Root Rib Right

May 3, 2010

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Well, after a few days of no work, then a few more of yardwork, and a few more of more no work, I made it into the garage tonight for an hour of work. Now that summer is approaching, the garage is getting a little humid. I’m going to start thinking about buying a portable air conditioner.

Tonight’s main task was to get any piece of the right elevator ready for assembly. E-709 (Root rib right) seemed to be a good candidate.

On the right, my trusty scotchbrite pad. In the middle, E-709 (Root Rib right). On the left. Well. You may call that beer. I call it "delicious."

Anyway, after deburring and scuffing, I broke out the #40 tank dies (understructure, so I want the dimples slightly deeper) and did all but the aft two holes on top and bottom.


For my hard to reach places, I use a steel bar with a countersunk hole in it, put the hole of interest on top, and put in a sacrificial rivet to use as a male dimple die. Then, I grab a flush set, and push the rivet into the hole in the steel.

Getting ready to ghetto-dimple.

Here’s a closeup of my steel bar for you to admire. The hole on the right is what I use for these tasks.

The hole on the left is useless, since I drilled it too far away from the edge of the bar. Dumb me.

Anyway, here’s a shot of one side of the E-709 after using this technique.

The bottom dimple is from the tank dies, the top two are with the rivet trick. Not perfect, but not bad for the hard-to-reach area. Based on my experiences on the rudder, the skin will sit just fine in these dimples.

Off to the paint-shop. And by paint-shop, I mean “a piece of cardboard on my trash and recycling bins.”

Up with the garage door for ventilation and on with the respirator before shooting the first coat.

While that dried, I snapped an action shot of me devinyling the inside of the skins. I also deburred all of the exterior sides of the recently drilled holes, but didn’t get to the insides, I’ll do that as soon as I get back into the shop.

Oh man, those stiffeners and rivets look nice.

Here are both interior sides done. (And by “done” I mean “done devinyling with just the parts I’m going to deburr, scuff, dimple, and prime.”) The rest of the vinyl will come off just before riveting, and will reveal nice untouched (and unprimed) alclad.

Pretty pretty.

Crap, I forgot to take a picture of me shooting primer on the other side of E-709, which is the entire basis for the title of today’s post. If you feel shortchanged, feel free to complain.

One hour.

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