Left Elevator Stiffeners, Part Uno

May 26, 2010

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Another quick night in the shop. First thing, I fired up my 6″ grinder (with a scotchbrite wheel attached) and edge-finished half of the stiffeners. After that (about 45 minutes of the total 1 hour in the shop), I started the stiffener to skin drilling dance.) In this first picture, I’ve just placed the elevator trim backing plate in plate for the effect. On the right, my first two holes drilled (into a sacrificial piece of MDF) on the bottom of the left elevator.

Bottom of the left elevator, working from inboard to outboard.

Here are three of the shorter stiffeners drilled, and the forward most hole on the last four drilled.

3 done, 4 to go.

All of them drilled.

Next, I uncleco the assembly from the table, and recleco just the front and back holes of the stiffener so I can flip the skin over to match-drill the last hole (it’s prepunched in the skin, but not the stiffener on a couple of the stiffeners). Then, I traced around the stiffeners with a sharpie, then pulled them off and clecoed them to the outside of the skin, again, to trace them with a sharpie. This will help me figure out where to remove the blue vinyl later instead of just guessing (like I did with the right elevator.

Of course, the stiffeners don't go on the outside of the skins, I am using them to mark the outside of the skin for devinyling.

See? All traced.

The inside, too.

lastly, I removed the stiffeners and marked them before prep for priming.

B2 is upside labelled upside-down. Maybe I should remake the stiffener. /sarcasm off.

One boring hour today.

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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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Primed Right Elevator Skin

May 19, 2010

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Well, it was a short night in the shop tonight, but after almost a week without building, it was a productive hour.

All that’s remaining before riveting the right elevator together is to finish up deburring, dimpling, and priming the right elevator skin, and doing the same (as well as getting a big enough dimple for the counterbalance attach screws) in the counterbalance skin.

First thing, I grabbed an oversize drill bit and started deburring.

I still can't bring myself to buy a deburring tool. Maybe I'm being stupid. (Who got sawdust all over my right elevator skin?!)

Then, I realized that the holes on the very front edge of the skin (for the pop rivets after you bend the leading edges together) will be very difficult to deburr if I wait until after bending to matchdrill them. I decided, like on the rudder, to drill and deburr them now.

Just making sure the #30 bit is the right bit.

After drilling, this looks like it will fit the bill when I am ready to start riveting the leading edges together.

After getting all of the holes deburred, I grabbed my scotchbrite pad and got to work scuffing. I grabbed an intermediate shot so you can see what I am doing.

Scuffity-scuff scuff.

After scuffing, I cleaned everything up with MEK (because it’s harder to clean well with the dimples) and started dimpling. Here is the inboard edge of the right elevator (which is upside-down on the table) after dimpling with #40 dimple dies.

I love dimpling. Don't know why... (Whose palm prints are all over my elevator skin!?)

A before and after shot of dimpling.

Please no comments on the lack of edge finishing here. I did all the edge finishing after this step.

Like I said, after edge finishing and another wipe-down with MEK (and the requisite drying time), I put the skin up on my garbage bins and shot some primer on the interior surfaces. If you look closely, you can see where I have left the blue vinyl on the inside of the skins. That is where I don’t want any primer (weight savings) after I am done. When the skin is dry and ready for riveting, I’ll pull the vinyl out and be left with nice shiny, untouched aluminum.

I cant wait to rivet this stuff together. I am proud of this elevator.

One little hour, but good prep work for riveting soon!

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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.

Yikes.

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.

Grrr.

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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I Love Tungsten (Started Riveting Right Elevator)

May 8, 2010

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Well, this morning, the girlfriend ran some errands, and I got my house chores done early, so I headed out to the garage to make some loud noises. Recently, I’ve been taking one component at a time from drilled through primed. It make my work sessions less boring (not a full day of deburring lots of parts, but rather one day of drilling, deburring, scuffing, dimpling, cleaning, and priming one part).

Anyway, today, it was the right elevator spar’s turn.

First, deburring. There's my oversize drill bit spun in my fingers.

Then I put a nice scuff on all sides and edges.

Scuffed and edge finished.

Then, I broke out the tank dies to do some dimpling.

I love these dies. Such high quality.

I know you guys have seen tons of dimples from me, but I still take pictures.

The male side.

And the female side. Apparently I have not edge-finished yet.

After finished dimpling, I grabbed this shot down the length of the spar.

Right elevator spar, dimpled.

I forgot to take a picture of the countersinking I had to do on the front (flanged) side of the spar. The spar needs to be countersunk to hold the flush rivets attaching the E-709 Root Rib Right. The elevator control horn fits over them.

Then, inside for cleaning and back outside to the paint booth.

One side primed.

While I was waiting for the back side of the spar to dry, I went ahead and pulled the vinyl off both sides of the E-713 counterbalance skin.

The vinyl comes off a lot more easily when it is warm out.

Then, I got the other side of the spar primed, and prepped for some riveting. I had already prepped and primed the two reinforcement plates that get riveted to the back of the spar.

There's my new tungsten bucking bar.

Here’s my setup for spar riveting.

You can't see the reinforcement plate, but those clecos are holding it on.


After 8 rivets, all I can say is…WOW. I love this tungsten bucking bar. 8 perfect rivets. With the older, and smaller, bar I was using before, things were always bouncing around, and my hand was vibrating, etc. With this bar, it is so easy to rivet. I should have bought this at the beginning of the project.

Wow, these are amazing shop heads.

Here's the other side.

I spent about 2 minutes just staring at the bar. Amazing.

I thought I would show you my grip.

8 more, also perfect.

Wuhoo, this bucking bar is great!

And, the other side of those.

I wanted to buck these, but I thought it would be better to squeeze them.

The spar to E-709 rivets.

These are the flush rivets I was talking about earlier. Of course, when the primer is only 30 minutes old, and you try to clean up some smudges with MEK, the primer will rub off. Duh.

I re-shot some primer over this right after this picture.

What a great day. I got to make loud noises, and I’m in love (sorry girlfriend) with my new tungsten bucking bar.

20 rivets in 1.5 hours. Good day.

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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.

Dimpling.

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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Bent Right Elevator Trailing Edge

April 28, 2010

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What a great night in the shop tonight. And, the airplane actually forced me to get something done on the house!

After work today, I needed to stop by the Aviation Depot to buy some hinges, wood, and an 1/8″ dowel rod for elevator trailing edge bending.

Since we’ve been wanting to upgrade the hardware in our house for awhile, I decided to buy the nice hinges, and used the replaced hinges for my bending brake.  Here’s a shot of our powder room door, mid-installation.

Top hinge is the new “oil-rubbed bronze” hinge. Bottom hinge is the old (builder standard) hinge. Looks a lot better.

Up close. I like the new one a lot better. (Later, I went around and made sure all of the crosses in the screw heads were straight up and down. It’s an anal retentive thing I do, especially with light switch plates.)

Anyway, after a ton of VAF research, Orndorff video watching, and builder website reading, I settled on the “other” method, which puts the hinges on the long face, and really only bends with the short side of the 2×4 (or 2×8 cut in half). You really only want that much bending the skin anyway, because the bend needs to occur locally at the radius, not away from the trailing edge. If the wood is imparting force in the middle of the skin, you will end up with the dreaded “bulge.”

Here’s my bending brake being assembled. I had six hinges, so why use them. I grabbed these 2×4, which were nice and straight, and just long enough for the trailing edge. I’ll need to replace these for the flaps and ailerons. I read somewhere they need to be more like 5 feet long for those.

Here it is after assembly. On the left, you can see my skin, that needs to be bent. In the middle, the three dowel rods I purchased. While I was standing in the store, 1/8″ seemed too small, so I bought a few different sizes at $0.50 each. Of course, everyone was right on, 1/8″ is perfect.

I’m going to put the trailing edge of the skin in the little opening at the bottom of the brake (as it is oriented in the picture).

First thing,  I screwed my bending brake to my 2nd workbench with one of the bending surfaces flush with the bench top.

Bending brake, installed.

Then, I put the 1/8″ dowel into the trailing edge of the skin and taped it in place. (Not shown in the following picture, because I was recreating the process for the camera. Look 2 pictures down for the dowel rod.) Then, you put the skin in the brake all the way against the hinges, and start bending.

This is not a fast process. It takes a surprising amount of force. I thought it was going to be a one shot deal, but it takes a lot of bending. You start with the skin against the hinges, then bend around the dowel. That took a whole bunch of times (I was stopping a lot to inspect). Then, you move the skin a little away from the hinge, and bend again. This allows you to really form the edge around the dowel.

If you pretend there is a dowel rod in there, this would be the first bend.

Here’s where I could get to with the dowel rod in place.

About halfway there.

Then, you remove the dowel rod and keep going, same deal, but a lot more gently, because I didn’t want to squeeze the trailing edge too much (now there is no dowel rod to prevent squash-age.

I thought this was good enough, but this is about 3/4 the way there.

Of course, because I thought that was good enough, I clecoed the skeleton into the skin.

It’s starting to look like something that could be considered an elevator.

But, after grabbing my straightedge, I’m getting some “fall-off” before the radius. This happens because the radius hasn’t been formed well, and then you pull the skin down to the skeleton, and it bends close to the trailing edge. It’s not terrible, but I know I can do better.

It’s not the dreaded bulge, but it is some pretty good “fall-off.”

Another shot.

No good here either.

Near the inboard edge.

Hmm. I unclecoed, and grabbed this shot. I’m about an inch from where I need to be, and the tension I am putting on the skin to pull it to the skeleton is causing that slight bend near the trailing edge.

About an inch.

I put that bad boy back in the brake and kept going. This time, I used two BFPs (the “p” stands for pliers. I’ll let you figure out the “b” and “f”) on either side of the brake and finished it up nicely.

More bending.

There we go. I made up that last inch, and now it rests right where the skeleton would go.

Much better. Perfect, in fact.

Here’s an end-on shot.

How great is this? A perfect bend.

Let’s get out the straightedge.

No fall-off before the radius.

Another place on the elevator.

And again, no fall-off. So happy!

After all that, I pulled the vinyl off of the outside of the elevator skins in preparation for deburring.

Hey! There’s shiny aluminum under there. Let’s start putting this bad boy together.

Total, it was two hours tonight, including bending brake construction. It was a great 2 hours though. I am extremely happy with the results. I have a perfectly bent trailing edge.

Boo-yeah.

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