Prepped and Primed Left Elevator Skin

July 11, 2010

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Well, after an exiting morning with the South Carolina Breakfast Club, I was fraught with motivation. (I don’t know if I am using “fraught” correctly…)

Next thing on my long laundry list of things to do on the left elevator is to prep the skin for riveting to the skeleton. First thing, I got out the soldering iron and pulled off some more of the blue vinyl. While I was at it, I pulled off the blue painter’s tape I had been using to protect the back-riveted stiffener rivet lines.

All that shiny aluminum really makes me happy.

Then, on to deburring. I deburred both exterior sides of the skins, and then moved on to deburring the interior of the skins. I follow very closely with my maroon scotchbrite pad to help me remember where I have deburred (you can easily tell the difference between a deburred hole and one that has yet to be deburred…I am more using the scotchbrite pad as an excuse to give my fingers a rest…it is hard spinning that drill bit over and over and over).

The background holes are #40 (3/32") and the foreground holes are #30 (1/8"). I drilled these holes to #30 now because I don't want to wait until after the skin bending (at which point I won't be able to deburr them). Also, having the holes to final size will help with the annoying pop rivets that go in them.

Next up, dimpling the skin-to-skeleton holes. I scuff the interior of the skins before dimpling, because it is easier to scuff without dimples getting in the way.

I use my masking tape trick on the male dimple die, and I get ZERO circles around the dimples. So nice.

All holes dimpled.

Time to move on to edge-finishing. This little 90° corner is a tough one, but I think this ended up nice.


After edge-finishing, I cleaned up, wiped everything down with MEK, and primed. Fast forward 30 minutes later, and now I get to pull the vinyl out of the skins (I’m trying to remind myself constantly to not forget the RTV in the trailing edge of the elevator bend before riveting.)

I probably add some time to the project by masking all of this stuff off and priming just the contacting surfaces, but I think it looks great (no one will ever see it) and I think I'm saving weight. Maybe not, but I sleep better because I do this.

It looks so good. I love this part of a subassembly, I'm getting close to riveting!

Last, but not least for the day was to prep and prime the two outboard ribs. These fit back to back and support the counterbalance and counterbalance skin.

On the priming table after getting a light coat of self-etching primer.

3.5 hours today on the project, but I’m only logging 3.0 here. See here for the other 30 minutes.

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Started Riveting Left Elevator Skeleton

July 5, 2010

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After the last couple work sessions priming various parts, I was getting all hot and bothered to rivet something. I thought I would tackle the spar reinforcements. I also forgot to charge the camera battery, so I’m using the new phone. Hopefully they turn out okay.

Here's the left elevator spar and reinforcement plates.

I got out a few rivets. AN470AD4-5 and -6.

Let's get riveting.

I clecoed the reinforcement plates and nutplates onto the spar, and riveted the four corners and one ear of the nutplate, then took out the clecos and riveted the rest.

The tape is a trick I have been using out of vanity. The rivets look better when they haven't been marred up by the rivet set.

After doing both plates, I put the spar back on the table.


And just to show you AGAIN how much I love my new tungsten bucking bar, here are the perfect shop heads.

The inboard shop heads.

The outboard shop heads.

Next up is to continue riveting on the skeleton, so I pulled E-705 out of the “recently match-drilled” pile and got it deburred, dimpled, edge-finished, and prepped for priming.

Ready to prime.

This is the other side after being shot with primer.

16 rivets set in 30 minutes of building after 30 minutes of shop cleanup (cleaned out the shopvac, etc).

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Started working on the Elevator Tab

June 20, 2010

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After some more days of not doing anything, I managed to make it out to the Pilots N Paws fly-in today. It was good motivation for working on the airplane.

Anyway, I’ve drilled the left elevator skin to the skeleton, and the next step is really to take everything apart, deburr, dimple, countersink, prep, prime and assemble…


I have some things that need to be done first. Mostly, the directions want you to bend the elevator tab “ears.” Well, I don’t think I want to go the bent route. Here’s what I am worried about. I don’t think anyone would really notice, but I don’t love the way this looks.

Bent trim tab ears. I think I'm going to cut mine off and make little ribs.

I think with some work, I could make them look like this, but given how finished these surfaces are, I don’t know if they started as bent ears or riblets.

WHOA! This is awesome. This guy really finished this joint up nicely. Everybody be jealous.

Finally, I found a really nice riblets version. I like this, and this is what I am going to be aiming for (although I am going to try to use solid rivets.

Great finish on the cut-instead-of-bend tab ears. I'm going to strive to make mine like this.

Anyway, I also think cutting the ears off (not bent down in the way) will allow me to use solid rivets in the blind-rivet locations on the top and bottom of the elevator (outboard trim spar rivets). We’ll see.

First step is to get the skeleton re-clecoed in the skin.

The trim spar and the inboard rib.

Van’s wants you to countersink either piece for flush rivets (not for any real flush reason…I think they need to be #40 size holes, and they don’t give you any universal head AN470AD3 rivets). Anyway, per standard practice, I dimpled both.

Dimpled instead of countersunk.

After clecoing together the skin, I am ready to start the headscratching with the tab. Let’s find the tab spar.

There it is.

Let’s go ahead and cut off these tabs. After careful measuring and marking, I’m ready to put blade to metal.

Inboard side. I'm nervous about chopping these off.

Outboard. (see how I lined up the line parallel to the flat portion near the top and to the left of the relief hole near the bottom? This doesn't work. Read on to find out why.

After a quick snip (not too close to my final line) I removed the vinyl from the interior of the skin in preparation for using a file and scotchbrite pad to clean everything up.

Devinling before finishing those cuts.

After working carefully with a file and edge finisher…

Looks good.

Before I really finalize things, I’d like to get my tab placement set up. First, I tried using this extra piece of rudder stiffener.

It worked okay, but I later switched to something a little longer.

After some moving around and fiddling, I re-read the directions, which tell you to bend the elevator ears down along a bend line that is perpendicular to the hinge line. Well, that means that the cut lines should be perpendicular, too. Of course, like I mentioned before, my original outboard line wasn’t perpendicular. All that file work for nothing.

I drew new lines (one on top of the other, ignoring the needed clearance).

Drawing new, perpendicular lines.

Then, I made a “pretty close” cut with the snips. I’ll need to really clean this up, as well as move the line to the left for clearance purposes (I’ll wait until the hinges are drilled to really see what I need. (The instructions call for 3/32″, but that is for the blind rivet head clearance that I won’t have to worry about.)

Pretty close, but still needs trimming and finishing.

Next, I moved back to the tab. Here’s my new line.

I'm bummed because the upper part of the tab, factory provided, is not perpendicular to the hinge line. That means there will be a slight angle there. Bummer.

After getting those refinished, I got the tab mocked up. I kind of worked backward. I want to use the inboard edge and the trailing edge to get placement, then verify I have adequate clearance on the outboard edge and between the tab and elevator for the hinge (there are some hinge dimensions on the plans). I think I’ll have plenty of room.

This looks good, but I'll have to keep trimming that outboard edge.

Here's a closeup. You can see the edge near the top of the tab is angled a little left. This is how it comes from the factory. The marker line and aft portion of the tab are both perfectly perpendicular to the hinge line (line through the center of the rivet holes).

Later this week, I’ll work on getting this perfect, then tackling the riblets that need to be constructed before doing any more work with finishing the skin.

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Drilled E-701 (Left Elevator Skin) to Skeleton

June 17, 2010

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Wow, it’s been a week since I’ve worked on the airplane.

I have an excuse, though. I’ve been installing wood floors. Here’s the living room, almost done.

Anyway, if you remember from the last post, I had the left elevator skin clecoed to the skeleton. I went ahead and match-drilled the skin to the skeleton. Instead of using my cordless drill (because it’s quieter), I broke out the air drill and went to town. I love the way that thing sounds.

Forgot to charge the camera battery, so it charged while I drilled.

After matchdrilling both sides, this picture is me in the middle of removing all of the clecos.

Then, because I felt like I would be short-changing you if I didn’t have two pictures for you, here’s another one.

After disassembly.

Here’s the catch, though. I have a lot of thinking and pondering to do about some things.

First of all, I am planning on cutting off the elevator tab (and elevator) bent ears and just making a rib out of them. Jason Beaver did it pretty successfully here and here, so I’m basically going to copy him.

The question is whether to prep and rivet the left elevator now, the cut off the “ears” after riveting, then try to fabricate a rib, matchdrill, dimple, prep again, etc., or should I re-cleco everything together and do all of that fabrication now.

Many people use blind rivets for the extra tab fabrication, but I think I am going to try to use solid rivets. I have had some success in the past with solid rivets in tight spaces using a special bucking bar (namely, the end of a BFS (“big-freakin-screwdriver”). The question will be about dimpling.

Also, I can probably cut the ears off, but leave a little extra material. I need to make sure I line up the cuts on the elevator and tab to minimize the gab between the two, and I don’t want to cut to much off of either side. Maybe I’ll mock them up, cut one side to where I think it should be, and make sure the other side can be cut more precisely to match the first cut.

Also, many people use blind rivets for the four trim spar rivets on both sides (per the plans), but I think I can assemble in an order that allows me to use solid rivets, especially since I’m going to cut the elevator bent tab ears off; I should be able to reach in there with a bucking bar.

See how much thinking I have to do?

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Drilled E-714, Clecoed Left Elevator Skin

June 10, 2010

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Hey Look! Andrew’s not dead! Yeah, I’ve been working on some house projects. Back to the left elevator tonight, though.

I managed to catch myself up with where I was and push on today. I need to get that counterweight drilled.

Here you can see the counterweight, counterbalance skin, and the two end ribs around which the other parts reside.

After placing the weight in position, you cleco on the skin (difficultly) and get ready to match-drill. Of course, I met the same challenges I did on the right elevator…namely, I broke a drill bit (#40 size). After getting a pilot hole drilled, I took everything apart and separately enlarged them all to #21. Air tool oil was used with great success after the pilot hole was drilled.

Ready to start drilling.

I didn’t take any pictures, though, because I was getting frustrated. (At first, I was dipping the drill bit into the oil, which meant I had to take the lid off. Then, after stepping away a few minutes later, I placed the screw lid (with the flip-up spout) back on the oil bottle and immediately flipped it over to aim oil into the pilot hole. Guess what! I forgot to tighten down the lid. There goes the lid, and about a 1/2 cup of oil…all over the counterweight, table, and floor.)

Now do you see why I forgot to keep taking pictures?

Anyway, after that debacle (which of course gets counted in the build time…it’s time spent building, right?)

Anyway, here is that same assembly (sans weight) before clecoing on the skin.

In preparation for clecoing on the skin, I needed to handle E-606PP, which is the trim tab hinge spar. Since I was looking ahead earlier and dimpled the hard-to-reach holes (you can see in the skin below), I need to do something with the spar to accept those dimples. If you read ahead in the directions, the spar is countersunk on the top flange (because the hinge is riveted beneath the spar flange, it can’t be dimpled), and dimpled on the bottom flange.

June 10 Update: After countersinking these four holes, I later did some more research and realized that the countersinks called for (due to the hinge) don’t really apply here, because the hinge stops short of these four holes. I could have (and wished I’d ) dimpled. Boo.

Here are the two parts that need to fit together nicely.

Finally, I got the skeleton and skin clecoed together.

Wuhoo. It looks like an airplane.

A solid hour. Maybe more this weekend.

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Primed the rest of the Left Elevator Stiffeners

May 31, 2010

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Tonight, I moved on with the left elevator by matchdrilling the upper stiffeners.

Here are the upper left elevator stiffeners, after trimming, being matchdrilled to the skin. First, I drilled and clecoed the forwardmost hole.

The three forwardmost holes clecoed.

After finishing, I traced the stiffener outlines on the inside and outside of the skin.

These will help me devinyl later.

You can see I have already done the lower surface of the elevator (it's upside-down on the table).

And, of course, since I forgot to add RTV to the right elevator (still trying to figure out a way to get some RTV in there), I wrote a little reminder on the inside of the left elevator.

Hopefully I'll see this as I pull out the last of the blue vinyl just before assembly.

Next, devinyl along the traced lines and then deburr and scuff.

Left elevator skin interior after devinyling, deburring, and scuffing.

Next up, I deburred and scuffed the remaining stiffeners. (I don’t have any pictures, but after this, they got dimpled and then primed.)

Because the upper surface doesn't have the trim reinforcement plate, there are 4 (instead of 3) of the short stiffeners.

Next up, devinyl and deburr the outside of the skin.

Skin devinyling.

A small tip here. I decided that at the aft end of the elevator, i would leave a little blue vinyl instead of connecting the upper and lower surface bare spots. This way, If I need to rest the elevator on its trailing edge, I won't be damaging the finish on the trailing edge.

Because it was late, I couldn’t use the c-frame.

Instead, I grabbed the hand squeezers and dimpled anything I could reach.

Just for kicks, I held up the trim reinforcement plate (and cover, still covered in blue vinyl) which will be riveted underneath the skin to the right.

Here are the other sides of the upper stiffeners getting primed.

I toook these inside for a good washing with Dawn before drying them, wiping with MEK, drying some more, and then shooting with primer.

I had a few more minutes, so I started match-drilling the skeleton. Here is one of the spar reinforcement plates being drilled to the spar.

I used my 12" #30 bit due to cleco-clearance issues.

Finally, before heading in, I shot a coat of primer on the other side of the upper left elevator stiffeners.


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Primed Some Left Elevator Stiffeners

May 29, 2010

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Not too much today. I got the lower left elevator stiffeners deburred, dimpled and primed.

Here are some of the stiffeners on the priming table.

Then, I turned my attention back to the skin to start devinyling.

Left elevator, ready to be devinyled.

Here are a couple lines showing my devinlying process. These are made with a soldering gun held against a wooden straight-edge.

Oh yeah, almost forgot. I stumbled across another Harbor Freight coupon. I bought this ~$10 storage container for wing hardware.

I have two already, one for rivets, and one for Empennage hardware. I assume I'll need a third for wing hardware (I'll combine the rivets from wing and emp if need be).

Okay, back to the project. I’ve pulled off some of the vinly strips.

Pulled off some of the vinyl strips.

Here, my devinyl line overlaps the tracing a little.

Another angle here.

So I put the trim spar in position, and realized I could move the line back a little, so that's what I did.

Next, I deburred and scuffed the skin in preparation for dimpling. (It’s easier to scuff before dimpling.)

The lines to the right have been scuffed, the trim spar reinforcement area has not.

A closeup of scuffed versus not-scuffed.

To scuff an area (in preparation for priming), I scuff in one 45° direction…

45° to the right.

Then, 90° from that.

All done. You can sort of see the two directions.

Finally, some dry stiffeners, ready to be backriveted to the skins.

Pretty stiffeners.

I always like to take a big picture shot at the end of the day.

Left skin, ready for dimpling.

Tomorrow, maybe a little skin dimpling, priming, and backriveting stiffeners.

One hour.

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