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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Fixed Right Elevator Trailing Edge

April 24, 2010

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I’ve been lacking in motivation recently due to some badly dimpled holes along the trailing edge of the right elevator. All last week, my error had been hanging over my head, and I was having trouble even motivating myself to fix them.

Saturday afternoon (writing this later) I mustered up some courage and drilled out 13 of the 14 trailing edge rivets on the right elevator. They are really not trailing edge rivets, but the aft-most rivets of each of the 14 stiffeners (7 on the upper skin, and 7 on the lower skin).

You can't even really see the damage in this picture...

Here’s a couple pictures of the damage.

You can see how the dimple kind of tweaked the skin. Boo damaged skin.

The above pictures was the worst one. This one was more typical.

A small ridge below the hole (in the picture) and a small dent above the hole (in the picture).

After getting them all drilled out (13 of them, one of them was good enough to leave alone), I set up the skin with a long backriveting plate underneath the offending holes and used a 2×4 laid spanwise on the stiffeners with some clamps to keep the skin surface flat. Then, I used 4 or 5 long pieces of tape to pull the upper skin back to allow plenty of room to work.

You can still see where the very trailing edge is starting to bend down. This is why I had the problem in the first place.

With no rivets in the holes, I used a small flush set (about 3/8″ diameter) and my rivet gun turned way down to flatten the dents (I’ll call them dents for dramatic purposes, but they were really just small impressions) and ridges (again, really just small high spots) flat. I put the flush set on either side of the existing dimple (which was okay, it was the area just outside of the dimple, where the edges of the dimple die set had tweaked the skin a little, where I was having my problem) and gave it a few taps.

After finishing one side, I took off the protective tape I was using and inspected. It ended up okay. I think if I were going to polish the empennage, it would bug me, but my latest paint scheme idea has me painting the elevators.

I did the other side, and then cleaned everything up, put some rivets back in the holes, and set up each side again with my fancy setup to actually backrivet the last hole of the stiffeners in place. It went perfectly, and I was really careful to hold everything very flat against the backriveting plate.

(By “perfectly,” I really mean “I messed up one of the holes, had to drill it out to #30 and use an oops rivet.” ) I’ll point it out.

Here are some examples of the replaced finished rivets.

This one looks great!

Pretty good. You can still kind of see where the damage was.

Holy crap, how did I do that to the rivet? This is the one that got drilled out again and replaced.

Here's the shop head for the oops rivet. This was my first real oops rivet. Not bad.

This one is okay.

Another very nice one.

It's not blurry in real life, I promise.

Whoa, who scratched my skin? It was probably the male part of the dimple die. That will hopefully polish out, (or it will get cleaned up and painted).

Another good one. In all of these, you can kind of see the larger diameter area that was dimpled.

This one is on the very end, as you can see the devinyling lines.

It looks the same as all the rest, of course, so you’ll never know, and I’ve already forgotten which side (top or bottom) it’s on.

Anyway, I drilled out 13 of the 14 original rivets, then had to redo one of those, so 14 rivets drilled out and reset successfully in an hour today. Not bad. I’ll add pictures when I can get them uploaded. Sorry for the lack of work recently.

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Right Elevator Stiffeners and Priming

April 12, 2010

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Today was pretty boring. All I did was trim the aft end of right elevator’s stiffeners and prime the two spar reinforcement plates.

Here's half of my right elevator stiffeners.

Of course, I finished deburring, edge finishing, and cleaning the two right elevator spar reinforcements. I even got the girlfriend involved. She took the parts inside and scrubbed them down with dawn. Now it really is “our” airplane.

Two spar reinforcements, primed on one side.

While that one side was drying, I finished up with the stiffener trimming. Here’s a shot of my weapon of choice.

Stiffeners and snips.

After I finished my first 7 stiffeners, I laid them into the skin, just for kicks.

Stiffener work is boring, but it means that there is backriveting coming soon, and I love backriveting.

Drink of choice tonight (only during piddly stuff, never during “real” construction): Rum and Coke. Mmm. Rum.

Rum. Coke. Stiffeners. Sharpie. And a damn dirty workbench. (Those splotches are ski-wax drippings.)

Anyway, I think it was an hour tonight, including the 5 minutes of double duty with the girlfriend’s help. I’m gonna get her to help more.

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Rudder 99 Percent Complete

April 5, 2010

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All I had left to do after rolling and riveting the leading edge was finish up a few rivets in hard-to-reach places and then finish screwing in the rod-end bearings.

The hard-to-reach rivets in this picture are the top two. For the other side, my squeezer actually fit in here when the opposite side rivets weren’t installed. The shop heads prevented me from cleanly setting these, though, so I had to use a thin steel plate as a bucking bar. Worked well.

Two hard to reach rivets bucked.

Here they are from the right lower side of the rudder skins. (I haven’t been using blue tape on the rudder as much and this is a mistake. I know it would have been a lot of blue tape, but it makes the skins look so much nicer. I will be using tape again after riveting to protect the skins.) I don’t think the rudder is going to end up polished, but I just hate the way those scratches look.

Nice and flush.

For the tip rivets (there were four that were hard to reach), I used a thin steel plate as a bucking bar for three of them, but then only had about 3/32″ clearance between the unset rivet and the shop head from the set rivet on the other side. I improvised by using a backriveting plate, the right rudder skin, then the already set shop head, then a screwdriver, then the unset rivet, then the left skin and finally a flush set. This worked out really well.

My setup for riveting the last (aft) rivets on the rudder top.

Here’s another shot with a flashlight assisting the digital macro setting on the camera. The point of the picture is the screwdriver, but it looks like I am going to have to replace that upper rivet on the right.

This worked well, but YIKES, look at that rivet on the right...also, the lower shop head doesn't look big enough. I'll get out the rivet set gage and test it.

Then, I turned the rod end bearings into the rudder by hand (I haven’t made the rod-end bearing tool yet), and with about 30 seconds of trouble, I figured out a great way to slip the AN3 bolts into the hinges of the vertical stabilizer with the rudder attached.

Sweet. This is an awesome step in the project. My first assembly. And it moves!

The bearings aren’t adjusted yet, and there are no fiberglass tips, but I’m so excited. More pictures!

A vertical picture. So nice...

I’m not sure if you can see it, but I have the internal rudder stop in there, too. (Although I don’t think it goes on the bottom hinge. I need to read up on it.)

And the requisite picture with Jack and Ginger.

Jack is a little skittish about being in the garage (where I usually shoo them back inside.) Ginger clearly didn’t like being out here either, so she was slowly scooting her butt up toward me trying to inch away from the airplane discreetly. Cute, Ginger. Cute.

Jittery dogs. They would rather be in on the couch watching TV.

Okay, dogs, you can go back inside.

Finally, I laid the assembly back down on the workbench for night night time. I'll take these apart and store them again in a few days.

And at the end of the night, I looked down and had spent an hour on the project. Look at that, I’m at exactly 100 hours! Two big accomplishments in one night. (Also, ten rivets. Don’t want to belittle them by being more excited about the hours.)

To do:

  • Clean up a few rivets
  • clean and re-prime some bucking bar scuffing of the ribs
  • Mount the fiberglass tips
  • Figure out how the internal rudder stop works.
  • Clean up some trailing edge dings.
  • Do a couple more once-overs to clean up any edge issues throughout the empannage.
  • Move on to the elevators.

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Riveted Rudder Trailing Edge

March 31, 2010

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Well, it’s been 3 days since I prosealed the trailing edge, so I mentally prepared myself for the dreaded riveting of the trailing edge.

Here's the trailing edge. Hopefully, the pro-seal is dry.

Next, I pulled out all of the clecos and admired how straight it looks.

Looks straight. Let's take a closer look.

Straight as an arrow. (Before riveting.)

The clecos were easy to pull out, not a lot of pro-seal on them, and there was very little remaining in the holes. The usual step here, however, is to clean them up. Here’s a before picture.

There's a little goop in there, but not much.

Here I am using a #40 in my fingers to scrape some of the pro-seal out.

This was tedious, but I want the rivets to sit nice and flush.

Here about how much came out of most of the holes.

Next up, put the rivets in the holes to prepare for backriveting.

Rivet in, ready to go.

Then tape to protect the skins.

And here’s my new backriveting plate. I wanted a nice long piece. It’s not quite as long as the trailing edge, but I didn’t have to move it around very much.

New 36" backriveting plate.

And my setup. The power tools are holding the skin flat against the table and backriveting plate.

Ready to go.

Let’s re-read the directions. HOly crap, the pro-seal gets everywhere.

I thought it was funny how I got sealant on the sealant step.

Alright, let’s start riveting. First thing, set every tenth rivet about halfway.

Okay... every tenth rivet.

Everything was going smoothly until I got to this rivet. Can you see what I missed here?

How come there is no dimple for the rivet on the right. Uh oh.

I pulled the rivet out, put my male dimple die in the hole, and gave it a good whack with the hammer.

Rivet is out, where is my #40 male dimple die?

There it is. Not bad for forgetting to dimple.

With the rivet back in. This is the shop head side, so you won't even notice. In fact, I dare you to try to find this hole when the plane is done.

Back to riveting. I followed the directions and kept riveting every tenth, then fifth, then third, etc., until they were all halfway set.

A nice halfway set shop head.

Down the line...

Verifying that things are still straight.

Yup. Straight. Although I know why the picture is blurry. Apparently I left the cap off of the MEK. Oops.

So then I flipped the rudder over, and finished up, per the directions. Except a few things started going wrong (which is why I don’t have any pictures.)

First, I must not have had the rudder down perfectly against the backriveting plate. A few of the manufactured heads were protruding from the skins. Luckily, they rivets were only half set, so most of them were able to be pushed back into their dimples and set further after flipping the rudder back to the original side and backriveting a little more.

Next, my rivet gun pressure was set too low (I thought this meant I was being careful). The gun wasn’t getting the job done before it jumped around a little and cause a couple very minute dings. A lot of my other dings have been pretty small, and these are even smaller. I doubt you would notice if I didn’t mention it, but I’m trying to capture my experiences here, so I offer it up as a lesson learned.

Finally, when they tell you to flip the rudder over to finish the half-set backriveted shop heads, I’m not sure how this is supposed to work. With the long backriveting plate, the rudder is being supported by all of the proud shop heads, so if you rivet the manufactured head side, you’ll be adding a local bow to the trailing edge. I didn’t buy this, so I stuck with the first side and got the shop heads pretty well flush. Once that was done, I finally flipped it over to make sure they were backriveted flush.

I have some pictures of the trailing edge at the end, but after I finished, I drilled out and reset the four rivets I had previously marked.

A nicely reset flush rivet. The skin got a little scuffed here. I hope this polishes out. (Although I am now thinking paint for the rudder.)

Here’s me drilling out  the lower nutplate mounting rivets. Notice the missing nutplate.

First, a #40 through the middle.

Then pop the heads off with the back of the drill bit.

Then, use a #30 to finish drilling out.

AH! I broke a drill bit. At least I was wearing safety glasses.

I must have been adding a little force of my own.

Okay, now I can install the nutplate.

Here it is clecoed from the outside.

I had read people say “the -7 rivets were too short here, I had to move up to a -8.” The warning bells were going off when I originally set these; I was thinking, “these -7s fit just fine, I don’t know what all the fuss was about.”

Of course, I tried the -7 with the nutplates installed, and yes, they were too short. I had to move to a -8, too.

These are long rivets.

A very bad picture of the nutplate installed.

Nutplate installed.

Okay, back to the trailing edge. I really didn’t get a great picture of how straight it was, but it is straight. There are a couple local areas where there is some slight  back and forth, but it is within a 1/32″ and it’s over the course of 4 or 5 inches. You won’t see it unless you scope down the edge, which I’m probably not going to let you do if you come near my plane. Just kidding.

Trailing edge picture.

All in all, an hour and a half today. 56 rivets on the trailing edge. 4 rivets drilled out elsewhere (but already counted in the final rivet count, so I won’t recount those). I’ll try to get a better picture of the trailing edge later and post it here. (The trailing edge picture at the beginning of this post is a good angle and focal length, I’ll try that one again.)

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Finished Backriveting Stiffeners

February 27, 2010

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I didn’t get to spend very much time in the shop today, but the half hour I did spend on the project was a good half hour.

I grabbed the stiffeners that I had primed on Friday night and laid (layed?) them on the left rudder skin.

Primed stiffeners, ready to be backriveted.

Then, I backriveted them.

All done.

Sorry about the lack of pictures.

116 backriveted flush rivets set.

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More Stiffeners, Some Skeleton

February 26, 2010

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Yes, Friday night! That means instead of being social, I get to stay home and work on the airplane. Wuhoo!

Anyway, after a good workout, I spent a couple hours in the airplane factory. First thing, I grabbed the two primed stiffeners from last night, and got them backriveted in.

#5 and #6 of 8 on the right rudder skin.

Then, I edge finished, scuffed, cleaned, and primed the last two stiffeners on the right skin. Once they were dry, I got those installed permanently, too.

#7 and #8 (two on the far left) of 8 on the right rudder skin.

I couldn’t help myself. I flipped the skin over, and removed the tape to reveal a very smooth skin. I like backriveting. The backriveting plate left some very very very small marks within about a dime sized area around the rivet heads, but I know those will polish out.

A finished right rudder skin. Those wrinkles in the vinyl in the middle where there when the skin was delivered. It didn't look like there was any damage underneath.

After spending some time admiring the right skin, I decided to finish the edges for the left skin’s stiffeners. After that, they got scuffed, cleaned, and set up on my fancy priming bench. Here they are ready for primer.

8 left skin stiffeners, ready for primer.

While those dried on one side, I decided to dive on in to the rudder skeleton. First, they have you cleco the R-904 root rib to the R-902 Spar. Tough step, but I managed.

Started on the rudder skeleton.

Then, because it was late, I had to skip the steps with the drilling and the fabricating the “shim” etc. I moved on to clecoing the spar reinforcement plates in. Here are the top two.

Fancy pants, huh?

Then, they have you grab the R-909? (tip rib) and R-912 counterbalance rib and cleco those to the spar after fluting, if necessary. It was necessary.

R-912 Counterbalance rib on the left, R-909 tip rib on the right. You can see I fluted the tip rib too much toward the aft end (top of the picture). I'll straighten it out tomorrow.

After that, they have you cleco the dreaded counterbalance skin to those two ribs. I’ve heard bad things about this step (mostly difficulty due to bad fit). Well, it was slightly difficult, but mainly due to perfect fit. If you start from the front (bottom right of the picture), everything will work out, but the fit is pretty precise. There is no slop in these prepunched kits.

The right side of the counterbalance skin clecoed on.

Then, I flipped the assembly over and clecoed on the left side of the counterbalance skin.

Left side clecoed on. (Hey, you can see my fancy fluting pliers back there.)

By then, the remaining stiffeners were dry on one side, so I shot the other side with primer and headed in for bed. (For blogging, and then bed.)


66 rivets today, all backriveted. Also, I passed 1000 rivets set today. A little bit of a milestone, although I think there are something like 20,000 rivets in the whole kit. So, I guess I’m 5% there.

Good night.

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