Left Elevator Counterbalance Skin

July 13, 2010

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A short half hour tonight. First thing was to grab the primed end ribs and get them clecoed to the left elevator spar. No problems there.

Looks good. Ready to rivet (but not tonight).

Next, I need to get the counterbalance skin taken care of (must be riveted to the skin before the skin can be riveted to the skeleton).

You can see I clecoed it in place and drew a line where the two overlap; I'll use this as my primer line.

Then, I realized I’m going to have a hard time deburring, dimpling, and scuffing with the blue vinyl on. [sigh] Off with the vinyl, re-cleco, redraw my line, then back off to deburr, dimple, and scuff.

After dimpling with tank dies where the skin sits under another dimple, and regular #40 dies where it doesn't.

While I had the #6 dimple die out (I’m attaching all fairings with screws for now), I moved over to the elevator skin and dimpled there, too.

Make sure you drill all holes that need to be dimpled with the #6 dies to #28 drill. This is slightly larger than the #30 you are used to.

Again (for the search engines), the correct drill bit size for a #6 screw and #6 dimple die is #28. Ask me what happens when you dimple a hole that isn’t drilled to the right size. (Hint: the same thing that happens when you overdimple using something other than a dimple die because you are too cheap to buy a #10 die…see below…)

Okay, back to the counterbalance skin.

These are dimpled to #8 (I don't have a #10 dimple die). last time, I used a punch set (with a little rounded lip on it) to enlarge the dimples to the equivalent of #10 dimple die.

Let’s countersink the counterweight as a female dimple die.

Looks good.

Uh oh. I went a little far with my makeshift die. I stared at this for approximately 0.0000001 seconds before realizing I had to scrap the part.

See the ginormous cracks? Yeah. Not good.

A closeup of the other one. Oops.

So, the reordered part count is up to 2.

I’m not worried, I have some other stuff I can be doing while I wait for a replacement counterbalance skin (E-713, $8.85) from Van’s. Also, I immediately put in my order with Avery for a #10 dimple die (along with some clecos, an edge roller tool, and some more drill bits).

USE THE RIGHT TOOL FOR THE JOB, ANDREW!

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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.

Edge-finishing.

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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Genuine Aeronautical Control Surface Interface Insertion and Adjustment Tool

July 11, 2010

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Well, I keep forgetting to make the rod-end bearing tool outlined on Sam Buchanan’s site (http://home.hiwaay.net/~sbuc/journal/odd-ends.html).

Anyway, I was standing in the aviation department at Lowe’s, and I turned around and there were the 1/2″ PVC sections.

All you’ll need is a “T” fitting, a coupling, and a length of 1/2″ PVC. They usually sell the pipe in 10′ sections, but if you dig through the pile, you can usually find a scrap piece that they’ll give you a discount on. I ended up finding a 6′ piece, but half was damaged beyond use. They marked it down from $1.53 to $0.51.

THAT’S AVGAS MONEY RIGHT THERE! WUHOOOO!

Anyway, I just eyeballed the pipe length and used an old hacksaw. It took about 10 strokes to cut through. (Sometimes it’s nice to be working with something that isn’t difficult to cut.)

Where's that yummy smelling PVC cement?

After cementing the T onto the straight piece. I used a hacksaw on the end of the pip and cut two slots (just wider than a rod-end bearing).

I had to use pliers to break these pieces off.

Then, I cemented the coupling on. I had to cut the coupling in half, because the coupling has two halves with a lip in the center.

It would be bad if this was the finished product.

After letting the cement cure, I took the end to my grinder, then scotchbrite wheel.

Looks good.

Nice and smooooooooth.

Let’s see if it works.

Wuhoo.

Although now that I am thinking about it, there may be a bigger size bearing I didn’t think about. Hmm.

DAMNNIT! While I wanted it to be long (to clear the bends in the front of the control surfaces), I made this 1/2" too long. I should have thought about where I was going to store this before making it.

No biggie, though. Since the coupling side is the harder side to make, I might just cut the T off, and cement a new T on.

30 minutes of Misc empennage work.

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SCBC in Salisbury, NC

July 11, 2010

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I woke up early this morning and headed down, via car :-( , to the South Carolina Breakfast Club (SCBC) in Salisbury, NC.

I took a whole bunch of pictures. No commentary yet. Maybe later.

These things are good motivation for me. I gotta get home and work on the airplane!

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Riveted Elevator Horn and Trim Tab Spar

July 7, 2010

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I don’t really love working in short bursts like this, but I do what I have to. Let’s do the elevator horn tonight.

I first clecoed every other hole. The left elevator horn was actually easier to cleco on than the right. I can't figure out why.

Anyway, a few loud noises later, and I had the first six done for the day.

Nice shop heads.

And again, a few minutes after that….

Six more, for a total of 12 so far.

Then, I convince the girlfriend to come outside and try her hand at squeezing.

Looks great.

She did great, but one of the rivets split diagonally as it was squeezed. It wasn't her fault, but I'll have to replace it tomorrow.

14 rivets. 0.5 hours.

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Riveted E-705 to Left Elevator Spar

July 6, 2010

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Well, I thought I would head out to the garage tonight to rivet 4 little rivets. I had the parts primed from the other night, and I just wanted to get something done on the plane tonight. I grabbed the elevator spar and admired how nice the countersinks looked.

Looks like I didn't get total coverage there on the spar, but that's okay, a light coat is all you really need.

Here are the AN426AD3-3.5 rivets that will go in those four holes.

Here's the first one set. Pretty nice, if you ask me.

I got the other outboard rivet set, then moved to the two middle rivets. Then, tragedy struck, and my flush squeeze set slid off part of the rivet as I squeezed. Boo.

"Well, this will be easy to drill out and replace." -famous last words.

My drilling wasn't perfect, but I didn't booger up the hole too badly...yet.

After resetting, I thought all was well, until I turned the part over.

That's not really flush, is it.

After 6…yes…SIX times of setting and drilling out a mis-set rivet, I finally gave up, drilled the hole to #30, cleaned up the countersink, dabbed some primer in the hole, and used an oops rivet.

OOPS! (Looks okay, though. And you will never see this.)

I can’t believe I had to drill out six rivets when trying to rivet four little AD3-3.5 rivets. Bummer. That’s not going to help my batting average…[calculator sounds]…yup…went from 5.7% drilled out to 6.0% drilled.

A frustrating half an hour tonight.

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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.

Pretty.

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 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).

Huzzah!

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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Trim Tab Fitting

July 1, 2010

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Okay. Today was a pretty productive day. I had taken everything apart, then realized I still had some more fitting to do on the tab, so I put it all back together again. Before that, though, I thought and thought about what to do about the two holes on the right side of the picture. These are for the fiberglass tips, and they are supposed to be matchdrilled later, after the counterbalance skin is installed as a lap joint underneath. How can I deburr parts that are riveted together if I drill through both? Maybe it’s not a big deal, but I decided to drill them to #30 now (for #6 screws).

Two holes the right before drilling...

...and after.

Then, I was thinking ahead about the safety wire trick you have to do with the hinge pin. Why not drill that now, so I can deburr before priming?

I drilled this just larger than 0.060, which is one of the biggest safety wire sizes.

Next, time to deburr and dimple the left elevator spar.

Me dimpling.

And after everything was dimpled, a nice picture down the spar of my blurry recycling bin, golf clubs, and motorcycle jack. (No motorcycle anymore, but the jack comes in handy to lift the corner of a car when a tire needs to be taken off for one reason or another.)

Spar! (I'm tired, so we are down to one word captions for the day.)

Another shot of the same.

Dimple! (Wouldn't it be annoying if I everything I wrote ended in an exclamation mark?!)

After edge finishing the two hinge reinforcement plates, I shot them with primer.

Primed!

Then, my attention turned back to the tab.  I’ve clecoed the elevator half of the tab hinge back in, and on the right you can see my drilled riblet!

Drilled riblet! (Okay, I've had enough of the exclamation points.....!)

Here’s a better picture. I basically drew a line perpendicular to the hinge line up from one of the holes along the trim spar, then spaced them at 1.5 and 3 inches. That spaced everything evenly, and gave me plenty of edge distance all around.

Don't look at my edges, they aren't finished yet, but you get the idea.

Then, I stuck the tab on and inserted the hinge.

As some would say, "Easy Peasy."

Other direction, just for kicks (not as much deflection due to cleco interference, but again, you get the idea).

Because I bought a longer section of hinge to replace my bad first attempt, my hinge pin was long enough to actually fit (Van’s says they will send you the real one (because it needs to be longer than 18″) in the finish kit.

I got to bending.

After more bending, I ended up with something like this.

Ooh, isn't that pretty! The safety wire hole I drilled earlier is in the middle there, and will allow me to safety wire this hinge pin to the spar so it won't COME OUT IN FLIGHT!

Then, I figured out how to do video. They speak for themselves, but keep in mind that while my gap is intentionally small, I still need to edge finish, which will open them up.

Another video, this time a little closer. You can see I am pushing and pulling left and right to make sure there is no interference even with the small amount of play in the hinge. I think I am okay, but this will probably open up a little after edge-finishing.

Two hours of late-night-hinge-pin-bending bliss.

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Left Elevator Riblet, Day 2

June 29, 2010

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Captain’s Log: Day 2. Great success with the riblet.

So after yesterday’s wasted (I know, it wasn’t really wasted) time making two FAILURES of riblets for the elevator trim cutout, today’s worked out much better.

I had actually woken up at 3am in a cold sweat; “Oh my gosh, I need to tie the front of the riblet into the elevator trim spar.” (Warning: Cold sweat may be exaggerated.)

Anyway, I got out the jigsaw with a fine metal-cutting blade and found that this technique was far superior to the snips, which leave little ridges along the cut.

So, more measuring, tracing, and drilling/cutting.

This is try #3.

Then, after judiciously edge finishing (which is a must before bending aluminum…ask me how I know.)

Okay, Those bends are pretty good, let's work on the front.

Hey pups! (I took about 15 pictures of them for your viewing pleasure, but this is the only one that wasn't too blurry.) Jack and Ginger, curious about the airplane.

Also, I had picked this surface conditioning kit up at Harbor Freight. 1-inch diameter, and blue is finer (I think) than maroon.

This worked pretty well for quick finishing. I want to try the larger sizes, too.

You can see from the paper template on the right that wasn’t going to tie in to the spar. I cut out the corners on the piece to the left pretty roughly.

Old template on the right, current work piece on the left.

So then I edge-finished and bent the three tabs that tie in to the spar. Because there was a dimple already in the bottom flange of the spar, I went ahead and drilled and dimpled that one ear on my new riblet.

How do you like the nice sharp picture of my set of needle files and permagrit block? (And very blurry pic of my riblet being dimpled. The yoke and die just barely fit.)

Here’s the almost finished product.

It's kind of cute.

So it doesn’t fit “perfectly” in the openeing, but this is close enough that I don’t need to remake it. I’ll tweak it a little and reduce some of those gaps you see in the coming days.

Pretty darn good.

The big gap on the left is actually the elevator skin bowing locally that I need to fix. The riblet is actually straight.

I'm so happy this one worked out.

Maybe later this week or this weekend, I’ll get this tweaked and drilled/dimpled. Then, I can move ahead with prepping the elevator for prime and riveting.

An hour of wuhoo!

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