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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Posted by Andrew

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…

BUT…

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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Posted by Andrew

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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Posted by Andrew

Bent Left Elevator Trailing Edge

June 2, 2010

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Sick again today, but I did get a little work done.

First, I spent a considerable amount of time looking at the 4 horizonal holes below. The plans show them as blind rivets, but there has to be a way to get solid rivets in there.

After much deliberation, I think if I drill them to #40 now (gasp, without matchrilling!?) Then I can deburr, scuff, and dimple the area now. I’ll do the same to the equivalent holes in the trim spar, and then attach (at a minimum) the top skin to trim spar holes with solid rivets. I think I will be able to get both sides, as I am planning on cutting off the “bent tabs” from both the elevator and trim tab.

First, drill to #40.

Then, deburr interior and exterior, and scuff the interior only.

I got the c-frame out again and dimpled the holes.

I should be able to make that work out for me, but more on the bent tab cutting later on.

Next up is bending the trailing edge. After inserting and taping a 1/8" dowel in the trailing edge, I bent it in my bending brake. This picture is about halfway bent.

Then, I removed the dowel, bent it the rest of the way, and did the same with the trim tab since I was in the bending mood. (Side note, the trailing edge on the elevator looked great, but was not constant radius…it was larger radius toward the tip. I grabbed the hand seamers and gently squeezed the areas so they were all the nice crisp radius that the inboard trailing edge was.)

Trim tab bent.

Also, I way overbent the trim tab. There are no stiffeners in there to stop you, so you can basically flatten the thing, even with the dowel rod in there. I opened it back up a little by hand, but it’s not perfect. If I can’t get it back to perfect, I’m going to order another one. I think I can work with this one, though.

This is a radius shot of both the elevator only.

Here's one with the tab held in place. Looks good to me.

Another sickly hour today. Can’t complain.

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Posted by Andrew

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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Posted by Andrew

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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Posted by Andrew

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