Backriveted Left Elevator Stiffeners

June 1, 2010

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I wasn’t feeling well today (sore throat, could harldy swallow), but after a nice long sleep-in and a nap in the afternoon, I went out to the garage partly because I wanted to sweat out some of the demons. I didn’t take a ton of pictures, but I managed a few.

I broke out the c-frame and dimpled the skins.

First up, skin dimpling.

I did much better on the trailing edge dimples than last time (see this post).

This is the worst one, but it still looks great, and is hardly noticeable unless you are really looking for it.

After dimpling, I wiped down all of the scuffed areas with MEK to rid them of fingerprints (oils) aluminum dust, moisture, etc., and then primed.

Primed interior. Notice how I leave a lot of the blue vinyl on the skins? This helps keep weight down (although undoubtedly adds to build time while I painstakingly trace around the stiffeners with a marker and use those lines to devinyl.

Moving back to the skeleton, I mounted a one-leg 1/4″ nutplate in the forward tooling hole of the counterbalance and tip ribs. This will hold any future weight I need to balance the elevator with paint.

I used an undersized countersunk screw in the tooling hole to help locate the nutplate, then drilled one hole and clecoed from the back.

Both holes drilled, and the main hole enlarged to something a little larger than 1/4"...I can't remember...maybe 5/32"?

Next, I moved back to the spar. I have read where a few people have added a hole in the lightening hole area of the elevator control horn/spar area. The right hole is for manual trim or for the (what I’ll call “retracted”) jack screw and wiring runs for the electric trim motor. I, like others, don’t like the idea of the wires and jack screw sharing the same hole, so I drilled another hole, in which I will add a 3/8″ snap bushing.

Pilot hole eye-balled.

Crap, I didn't even get a picture of the final size hole. (I drilled it to 3/8".)

After completed the extra hole, I noticed the skin was dry. Nothing to stop me from backriveting, now.

Rivets place in, and taped to, the first stiffener row.

Same thing with the trim reinforcement area.

After backriveting the trim reinforcement. Man, this makes me happy.

The next couple rows, done.

The bottom half went smoothly. The top half now has rivets taped in place.

Where are those stiffeners?

This isn't a very exciting picture, but they are all riveted.

Here's the inside.

I love this picture. This is the trim reinforcement plate area.

So nice. (That scratch at the top is very superficial. It'll buff right out, I promise.)

Biggest lesson today was about the aft-most rivet in the stiffeners. When bending the skin out of the way to reach that rivet, everything twists out of alignment. If you start with that rivet, it is easier to make sure everything is flush than if you rivet the forward ones first. Start from the back and move forward. You will get better results.

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Started Left Elevator

May 24, 2010

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Well, it’s monday. And even though I have a couple things remaining on the right elevator, I am going to follow the flow of the directions and move on to the left elevator before coming back to finish both of them.

In addition to the items they want you to do to both at the same time (roll leading edges, install rod-end bearings, etc.), I’ll have to come back to do three things on the right elevator:

  1. Fix a few over-driven rivets (and a couple that bent over that I didn’t catch at the time.)
  2. Figure out how to add RTV to the trailing edges after the fact (anyone have any ideas?)
  3. Trim down the counterbalance. I elected not to do this on purpose.

Anyway, on to the left elevator. Here’s the obligatory changing-of-the-plans shot.

On to the left elevator (and trim tab).

As I only have about a half an hour tonight, my plan was to just cover the basics. First, lay out all of the left elevator parts.

It doesn't look like a lot of work...

Devinyl the skeleton parts.

This picture is almost identical to the one before it, except for the missing blue vinyl on the skeleton parts.

Then, on to real work…kind of. The manual wants me to attach the hinge reinforcing plates to the spar, then move to the outer ribs.

Here you can see the two outer ribs fluted. I haven't straightened out the rib flanges yet, will get to that soon.

Blah blah blah, assemble the skeleton. For now, I didn’t do any match-drilling. I do that hole-by-hole as I take the thing apart.

This one will be more interesting due to the trim spar.

Finally, I found one more of the stiffener angles. I got that devinyled and then cut from hole to hole to form some of the smaller stiffeners.

More small stiffeners. These go between the main spar and the trim spar (ahead of the trim tab).

With that stuff done, I headed inside and caught someone with their hands in the cookie (doggie-treat) jar.

That bottom shelf has the doggie-treats on it. (We have really patient dogs. /sarcasm off)

Lucky you, I got some video.

Anyway, a short half hour of left elevator prep.
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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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More Drilling, Deburring, Scuffing and Dimpling

May 9, 2010

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After we got back from my first Pilots N Paws rescue, I was excited to keep working on the airplane.

I needed to start on the tip rib and counterbalance rib, so I needed to get the holes in the counterbalance to final size (#12, for a An509 screw).

I had some trouble awhile back with drilling the counterbalance holes to final size, and I don’t have any boelube, but i figured any lubrication would work better than none, so I poured some air tool oil into the holes and tried again.

This time, it worked much better. (I still got stuck a few times, but I didn’t come to a grinding halt like I did last time.)

Here's the counterbalance after drilling to #12.

I clecoed the counterbalance skin back onto these two ribs, inserted the counterbalance, and matchdrilled through those to make these holes in the ribs.

Nice job with the blurry picture, right?

Next up, deburring.

There's my trusty deburring bit.

Then scuffing.

Bottom rib (counterbalance rib) is scuffed.

After deburring and scuffing the tip rib, I dimpled all but the last 2 holes on the top and bottom of the rib.

The two non-dimpled holes are not shown here. I'll have to get the countersunk steel plate out to get those.

Next, I clecoed the counterbalance skin on the right elevator skin and marked with a permanent marker where I wanted to scuff and prime. Some of the edges here have to be broken to make the skins seam from spar to coutnerbalance skin a little smoother. More in a later post.

Above this line, the right elevator skin overlaps, and will need a coat of primer.

Then, out with the trusty blue tape.

Taped and ready for scuffing.

Then, I pulled out my #8 dimple dies (don’t have #10 dies, which are the correct dies for a #12 hole and AN509 screw) and dimpled the counterbalance skin. The countersinks on the right are the correct size. I need to figure out how to dimple the skin on the left a little more.

After this shot was taken, I screwed the correct screws into the assembly and tried to tighten them down to dimple more, but I didn't want to strip anything, and it wasn't really going to work.

I’m going to research how people did this without #10 dies later.

No rivets set, but a good hour on the plane.

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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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