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┬ábent 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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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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