Primed 3 More Main Ribs

January 7, 2011

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Warning: Boring post alert!!

I prepped and primed 3 more ribs tonight. I had prepped R1 yesterday (I numbered R or L then from 1 to 14 starting at the inboard rib). Today, I got ribs R2-R4 done. So…


(There are still 24 more main ribs to do, then 12 more leading edge ribs and probably 12 more tank ribs.)


R2, R3, and R4 just after being shot with some self-etching primer.

Anyway, yesterday’s rib took me an hour.

Today’s 3 ribs took me an hour.

(At this overall rate…4 ribs in two hours, I’ve got 10 hours of rib prep left. At the rate of 3 ribs per hour, I have 6.6 hours left.)

At least I’m getting faster. (I’m not sure how many more ribs I can do in an hour, I was pretty efficient yesterday.)

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Primed Elevator Trim Tab

August 19, 2010

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Well, I got a few more things done on the tab tonight.

First thing was to prime the outside of the elevator tab where the surface mates with the tab horns.

Here's the mating surface, ready to be primed.

After reexamining my countersinks in the trim tab spar, I decided to re-countersink them. This time (after reading the guidance in the construction manual about how to do this on the flap), I used the trim hinge as a countersink guide. This worked much better than the piece of wood.

Nice countersink on the left. The old (wobbly) countersink on the right.

Then, everything was put up on the cardboard piece for priming.


After the parts dried, I started in on riveting per the plans.

Everything was fine after 7 rivets, until I paused to re-fit the tab on the elevator.

4 of the first 7.

I was getting a little bowing (top skin concave, bottom skin convex) in the tab skin due to what appeared to be distortion of the tab spar. I drilled out the 7 rivets I had set and spent a little time re-tweaking the spar.

A fit check. You can't see any of the bowing very well, but it is definitely not satisfactory.

After re-tweaking (adjusting the spar flanges on the tab) and refitting a few times, I had things lined up much better. It’s not perfect yet (maybe more work on this tomorrow will get it right), but it is definitely improvable.

1 hour today.

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More Trim Tab Work

August 17, 2010

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Well, before I can dive into the wing, I need to finish up the trim tab. All that’s left is to fabricate two riblets, get everything prepped and primed, and then rivet the tab together.

First, let’s get some riblets made up. Just like the elevator riblet, I started with some thick paper.

I used the packing list envelope from the wings, because it was literally right in front of me when I started.

I got the larger one cut out of 0.025″ aluminum sheet pretty easily, and the first try fit like a champ. I moved on to the smaller one, hoping for similar luck.Fast forward a couple minutes (many minutes!)…

Can you say "third time is a charm?"

Nope. Third one wasn’t good either.

Let's try again (fourth time). I just couldn't get the bends right.

That one worked. And of course I forgot to take a picture.

I drilled a couple holes in each riblet through the skin.

Finally, fourth time is a charm.

Wuhoo, let's get this tab finished.

But, it was getting late, and there were a couple of puppies somewhere that needed attention. (Turned out, they were asleep when I went inside, and I got growled at. Thanks, puppies.) Before I headed inside, I disassembled the tab and pulled out the wing spars to inspect.

Tab components, ready for cleaning and priming.

After looking the spars over, I found many places where the spars had been “polished” with a scotchbrite bad to work out small scratches. It seems that everyone has these, and is no cause for alarm.

On the other hand, I found some bad juju. This is a closeup of a couple dings that look like something bounced on the spar. Keep in mind, that hole is a #40 (3/32″), so these are really small.

Still, that's not good.

Whoa. What. Is. That!?

Holy frijoles, Batman! That is a huge dent in my spar flange!

Here's a closeup of the dent with a straightedge held over it.

Another angle.

I took a couple pictures of the underside of the flange. I tried to use the light to demonstrate the distortion.

That curved white streak is actually the light reflecting off of some spider cracks in the anodizing.

Here's another angle.

Not really related, I just snapped a picture of the spars laying on the table.

At least they look pretty.

1.5 hours on the trim tab today. I’ll email Van’s first thing in the morning about the spars and then post what they say.

I’m pretty disappointed though. Nothing could create that dent without making a big noise, maybe something being dropped or falling over. Which means someone probably knew it happened and didn’t say anything, or the inspection process didn’t catch it. Either way, I’m not super excited. I’m guessing it wasn’t Vans’ fault, but hopefully they will make it right.

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Left Elevator Counterbalance Skin

July 13, 2010

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A short half hour tonight. First thing was to grab the primed end ribs and get them clecoed to the left elevator spar. No problems there.

Looks good. Ready to rivet (but not tonight).

Next, I need to get the counterbalance skin taken care of (must be riveted to the skin before the skin can be riveted to the skeleton).

You can see I clecoed it in place and drew a line where the two overlap; I'll use this as my primer line.

Then, I realized I’m going to have a hard time deburring, dimpling, and scuffing with the blue vinyl on. [sigh] Off with the vinyl, re-cleco, redraw my line, then back off to deburr, dimple, and scuff.

After dimpling with tank dies where the skin sits under another dimple, and regular #40 dies where it doesn't.

While I had the #6 dimple die out (I’m attaching all fairings with screws for now), I moved over to the elevator skin and dimpled there, too.

Make sure you drill all holes that need to be dimpled with the #6 dies to #28 drill. This is slightly larger than the #30 you are used to.

Again (for the search engines), the correct drill bit size for a #6 screw and #6 dimple die is #28. Ask me what happens when you dimple a hole that isn’t drilled to the right size. (Hint: the same thing that happens when you overdimple using something other than a dimple die because you are too cheap to buy a #10 die…see below…)

Okay, back to the counterbalance skin.

These are dimpled to #8 (I don't have a #10 dimple die). last time, I used a punch set (with a little rounded lip on it) to enlarge the dimples to the equivalent of #10 dimple die.

Let’s countersink the counterweight as a female dimple die.

Looks good.

Uh oh. I went a little far with my makeshift die. I stared at this for approximately 0.0000001 seconds before realizing I had to scrap the part.

See the ginormous cracks? Yeah. Not good.

A closeup of the other one. Oops.

So, the reordered part count is up to 2.

I’m not worried, I have some other stuff I can be doing while I wait for a replacement counterbalance skin (E-713, $8.85) from Van’s. Also, I immediately put in my order with Avery for a #10 dimple die (along with some clecos, an edge roller tool, and some more drill bits).


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Riveted E-705 to Left Elevator Spar

July 6, 2010

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Well, I thought I would head out to the garage tonight to rivet 4 little rivets. I had the parts primed from the other night, and I just wanted to get something done on the plane tonight. I grabbed the elevator spar and admired how nice the countersinks looked.

Looks like I didn't get total coverage there on the spar, but that's okay, a light coat is all you really need.

Here are the AN426AD3-3.5 rivets that will go in those four holes.

Here's the first one set. Pretty nice, if you ask me.

I got the other outboard rivet set, then moved to the two middle rivets. Then, tragedy struck, and my flush squeeze set slid off part of the rivet as I squeezed. Boo.

"Well, this will be easy to drill out and replace." -famous last words.

My drilling wasn't perfect, but I didn't booger up the hole too badly...yet.

After resetting, I thought all was well, until I turned the part over.

That's not really flush, is it.

After 6…yes…SIX times of setting and drilling out a mis-set rivet, I finally gave up, drilled the hole to #30, cleaned up the countersink, dabbed some primer in the hole, and used an oops rivet.

OOPS! (Looks okay, though. And you will never see this.)

I can’t believe I had to drill out six rivets when trying to rivet four little AD3-3.5 rivets. Bummer. That’s not going to help my batting average…[calculator sounds]…yup…went from 5.7% drilled out to 6.0% drilled.

A frustrating half an hour tonight.

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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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