I Hate Dimpling Stiffeners

August 24, 2011

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Well, can you guess what the airplane-building activity was? Maybe from the title?

Yup, you guessed right. Deburring and Dimpling stiffeners.

Here are the tools of the trade. An oversize drill bit, spun in the fingers to deburr. And, my normal dimple dies in my economy squeezer.

After one stiffener...

After 32 stiffeners.

For some excitment tonight (since otherwise, it would be a little lacking), let’s break out the calculator.

2 ailerons, 2 sides per aileron = 4 aileron sides.

4 aileron sides, 8 stiffeners per side = 32 stiffeners.

32 stiffeners, 7 holes per stiffener = 224 holes dimpled.

224 holes dimpled, 2 sides per hole = 448 deburred hole sides

448 deburred hole sides, 2 spins per hole = 896 spins of the drill bit.

My thumb and fore-finger hurt.

0.5 hour.

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Tank Attach Nutplates, Left Lower Spar Flange

October 21, 2010

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With the girlfriend gone for the night, I managed to clean up all of the electrical stuff I had out messing around with my wig-wag experiment, and pulled the left spar out of the box. Here it is, in all of it’s golden glory.

Golden Glory!

First step is to countersink the tank (and access plate) nutplate attach holes. First, you have to run a #40 drill through the holes or else the countersink pilot won’t even fit in the hole. Here’s one of my first countersinks on the left spar.

I went back and cleaned this one up after testing with a AN426AD3-11 rivet (-11 because it's easier to get back out while testing countersinks...it's so long you can just push it back out from the back.)

These countersinks are a little better. (The one on the right is a tad deep, but should be okay because these are just nutplate attach holes.)

I left the door to the house open so the pups could come out to visit.

Hey guys (Jack and Ginger).

Hey Andrew, how about one of those artsy shots down the spar after countersinking the nutplate attach holes?

Sure, here you go.

Then, I pulled the K1100-08 nutplates out for the tank attach holes and the K1000-06 nutplates out for the access plate holes, then clecoed one side in, and put the required rivet (AN426AD3-4) in the holes.

Where’s my squeezer?

It's right there on the table, dummy.

Then I squeezed some rivets and removed the clecos.

Squeezed (repeated 41 more times.)

Other side done. (Repeated 41 more times.)

Under the hood, things look good. I still like this new Cleveland main squeeze much better than my economy squeezer.

Pretty shop heads.

Down the row.

I then laid the spar down and saw this guy.

Yikes.

Whoa. Scary.

After a little internet research, I think I’ve figured out he (actually she due to her size) is a red-back.  I’m going to keep looking though. I don’t want it to be a red-back.

1.0 hour. 84 rivets.

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Started on Right Wing Tie-down Bracket

August 26, 2010

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Wuhoo, the new squeezer showed up!

After a few minutes of messing around with it, I grabbed the two K1000-4 nutplates and studied the plans carefully on which side of the spar they go. A quick hint (other than just reading the plans) is that the nutplates go on the side that couldn’t possibly need to be flush (in between the spar cap bars).

Anyway, here, I’ve countersunk for AN426AD3-6 rivets.

The two larger holes are examples of where Van's (or Phlogiston) buffed out some spar scratches with some scotchbrite.

Oh yeah, I also flipped the spar over and deburred (you can hardly see the deburring) the backside of the holes I drilled to #40.

The little silver rings are where I deburred. Because these will be totally covered by the nutplate and the shop head, I'm going to refrain from spot priming them.

I used the new squeezer to set my only 4 rivets today.

Don't these look pretty? (There are small rings around the rivet heads. That is from the cleco I used to hold the nutplate on while riveting the other side.) It seems weird the cleco made that little mark.

Moving on to the tie-down bracket. First thing, I need to fabricate the W-726 spacers from this 1.25″ wide angle stock. I’m supposed to cut 4 of them, 2 for each wing/tie-down).

Why is this one on the ground? Is it because the light is good for the camera? NO. It's because it is @&*!@ hot after cutting. Ask me how I know.

Here are the other three.

Each of these spacers should have a 1″ hole cut in the center for lightening (not lightning). Since all of my hole saws are in sizes other than 1″, I decided to grab the W-731 tie-down bracket and get to work on that.

Okay, the manual says to cut the tie-down bar to length from the AEX stock.

Okay (…searching plans…), looks like 7  15/32″. Of course, I measured 7  7/32″ marked, and almost cut before my gut told me something was wrong.

The bar is actually 7 16/32" ( or 7.5"), so I'm not going to cut them 1/32" when I'm sure the edge finishing on the scotchbrite wheel will be more than enough. (Also, it doesn't appear the extra 1/32" will interfere with the top or bottom skin at all.

I keep walking by this sticker and laughing. I thought I would share.

Translation: "If something doesn't fit right, you've royally screwed something up."

Okay, back to the tie-down. After marking and drilling the one (of four) holes for the spar in the bracket to 3/16″, I stuck an AN3-7A bolt in there and just eyeballed the alignment.

(You are supposed to drill just one, then fit the bolt through the whole assembly. Then, you flip the entire assembly over and matchdrill the tie-down bracket from the back.)

I was a little concerned that there was some overhang on the right side of the bracket. (I measured and drilled very, very carefully).

Looks like there is some overhang on the plans, too. Sweet.

Anyway, I stopped there because I can’t really matchdrill everything until I get the spacers placed behind the tie-down bracket, and I can’t really do that until I have the lightening holes drilled (the spacers will be riveted to the tie-down brackets in four places, which in turn hold some nutplates on).

Here are my spacers for the right tie-down bracket.

1 hour, 4 rivets.

Now, I need to find a good hole saw or fly cutter.

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Bought Cleveland Main Squeeze

August 21, 2010

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Recently, I’ve been kind of unhappy with my economy squeezer that I bought from the Yard. (I think Avery sells the same squeezer).

The squeezer is great for the majority of tasks on the empennage, but it only has one yoke, and I really need a no-hole yoke for some of the tighter-access areas at the end of ribs and such.

So, to buy a no-hole yoke, it looks like I’m going to have to buy a new hand squeezer (insert long back and forth about pneumatic squeezers here. I’m okay with hand-squeezing for the whole airplane, but I want one that can exchange yokes with a pneumatic squeezer if I decide to get one in the future).
So, for no small chunk of change (thanks, savings!) I got Cleveland’s Main Squeeze model 22 and the 4″ Thin-Nose Pneu. Yoke. I won’t be able to use this yoke for dimpling (still have the economy squeezer for that), but this will be great for squeezing rivets.

Aug 27, 2010 Update:

My new squeezer showed up. The actual squeezer is unbelievably light, and the yoke is unbelievably heavy. Even before installing the yoke, I can tell this is a much higher quality tool than my “economy” squeezer.

Here are the two separate purchases from Cleveland.

Ready for ACTION!

This should give you an idea of the difference in quality between the two.

In addition to being easier to squeeze, I am most impressed with the yoke. While I was squeezing rivets with the smaller 3″ yoke, sometimes the yoke would “give” a little. I can only describe this as the “c” part of the yoke opening ever so slightly. This had the result of pulling the top of the yoke back just a little, sometimes shifting the shop head a little to one side, or in some cases, sliding the flush set along the manufactured head side during squeezing. Most of the rivets turned out okay, but I no longer have this problem with the new yoke.

Here’s a picture of SRS (shifting rivet syndrome).

Big difference in quality (pronounced "price reflects this") and operation.

Bravo, Cleveland.

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