Right Leading Edge Inboard Rib Redux

June 17, 2011

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Since I’m out of MEK and I didn’t get a chance to stop by the store on the way home, I decided to work on the new inboard leading edge rib I ordered for the right side. If you remember back on May 13, 2011, I discovered that by having the inboard face of the rib lined up with the edge of the leading edge skin, the drilled holes ended up being too close to the web of the rib. (See this picture specifically.)

Anyway, let’s see if we can’t get a better alignment.

First thing, I kinda-sorta set the rib in place and just made some small marks where the holes would be. This is so I could pull the rib back out and flute it appropriately before drilling.

Marks made.

After edge-finishing and fluting, I stuck the rib back in place where I wanted it, then started matchdrilling.

A few notes:

  1. Since the leading edge skin was dimpled, I didn’t include the W-423 (I just made that part number up) join plate. The rib and skin fit was secure enough that it’ll work out.
  2. I ended up lining up the outboard face of the rib web with the skin edge (make sense?). Said another way, the rib sticks out a little further than the skin.
  3. If it happens to be May 13, 2011 and you discover that your rib drilling on one wing didn’t work out, AND you did both wings the same way, you should probably order both inboard ribs again, instead of waiting until June 17, 2011 (TODAY!) to check the left wing. Doh! I messed that one up too. Now I’ll have another one of these.


Finally, I clecoed the leading edge on the wing (I don’t know why you can’t see any clecos here), made sure my x’s from earlier still lined up over the tiedown hole, and drilled a 3/8″ hole for the tiedown ring.


I still need to tidy it up a little, and probably go to 7/16″ instead of 3/8″ (the tiedown ring is 3/8″), but I’ll leave that for another day.

0.5 hour.

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Clecoed Bottom Skins and Leading Edge on Right Wing

January 31, 2011

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Oh man, what a great day!!

After some good advice to stop worrying about the wing twist too much (“you’ve got a pre-punched kit, it’ll work out”), I got started on some of the next tasks on the right wing. First, I clecoed on the right top skins, and then grabbed the right leading edge and sat it on the main spar.

Looks like a wing!

Oh wait. One of the next steps is to trace some lines on the lower skins (forgot those) that intersect at the tiedown hole so I can transfer those lines to the leading edge so I can verify that the leading edge prepunched hole for the tiedown is correct. I haven’t attached the tiedowns yet, so I went searching for the hardware.

Apparently you need an AN3-7A bolt, a couple AN960-10 (and L) washers, and an AN365-1032 nut.

I couldn’t figure out which washer (skinny or fat) goes on which side of the spar, so I looked at the tiedown area of one of the drawings (can’t remember which one.)

First, though, I have to finally sort out which washer …-10 or …-10L is the skinny one. Turns out, I should remember that “L” means “lean” (not really, but that’s how I’ll remember it.

AN960 Flat Washers
Bolt Size OD Thickness Part No.
#10 0.438″ 0.063″ AN960-10
#10 0.437″ 0.032″ AN960-10L

Anyway, I hope that having looked that up now, I’ll remember which is which.

Okay. Looks like the -10L washers go on the bolt head side of the AN3-7A bolts.

Then, I realized that I don’t really need to tighten these things up. I’ve got some work to do in the future on the bellcrank brackets and bushings, etc., so I really just need to set these in place.

After putting the four bolts through the tiedown and clecoing on the bottom skins, I've got this.

Next, they want you to draw a few lines on the bottom skin that intersect at the tiedown hole.

You can just barely see my lines on either side of the access hole.

Next, I slapped the leading edge into place (but first had to notch my angles…bummer).

I only had to notch very slightly. Still very annoying to me.

After starting (pronounced “attempting”) to cleco on the leading edge, I realized I am going to need some mechanical advantage to snug everything up so I don’t have to use the clecos to pry things into place (a big no-no).

I got out a few 2x4 scraps and placed them against the rear spar. (This is so the straps don't put any pressure on the aft end of the skins.)

Strapped! (Not very much, just enough to act as a third hand while clecoing.)

After a good  30 minutes of the most difficult clecoing on the project, I had the leading edge nice and secured to the right wing.

Notice the amount (lots) of clecos on the aft part of the leading edge.

I think this is just a picture of the bottom side of the right wing.

Then, I extended my lines back onto the leading edge.

The intersection of the lines is sooooooo close.

I didn’t really believe I was off a little (although this is normal), so I grabbed this picture from the inside. (Depending on how precisely you place the tiedowns when you measure and drill them to the spars, you’re hole may be off here.)

That little tiny light is so close to the center of the tiedown hole, I'm going to start there, and file a little bit in one direction if I have to adjust.

Anyway, I decided I don’t want to start on drilling the skins to the skeleton until I do some more clecoing. I’m going to break down and just order like 400 more clecos before drilling. It can’t hurt to cleco every other hole (Van’s suggests every 4th hole before drilling)…things will only be lined up better, and since I’m already worried about twist, this will help me sleep at night.

A quick survey of tool joints yields the following for 3/32″ spring cleco prices.

3/32″ Spring Cleco Prices
Source Price per Cleco
Aircraft Spruce $0.43, plus shipping
Avery Tools $0.42, free shipping >$95
Brown Tools $0.44, 0.42 if >100, free shipping >$95
Cleveland Tools Website is not working…
Vans Aircraft $0.40, plus shipping
The Yard Store $0.40, free shipping >$100.
PlaneTools.com $0.79…WHAT?!!
Aircraft Tool Supply $0.49, plus shipping.
Innovative Tooling Services $0.35, free shipping >$100

UPDATE: Just found Innovative Tooling. The picture on the page for 3/32″ doesn’t show a silver cleco, but I’m assuming they just used the same picture. Just placed my order, we’ll see how they are when they arrive.

OLD: Looks like the yard store wins…they used to have bulk used clecos in 3/32″ size, but I called today and they are out. I’ll have to order new clecos, but bummer they are still $0.40 each. (By the way, who gets off selling clecos for $0.79 each?)

Anyway, I”ll order some tomorrow. One last picture of the WING! that’s in my garage tonight.

This makes me happy.

1.5 GLORIOUS, PRODUCTIVE hours. Night’s like tonight make all the other crappy nights worth it.

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Leading Edge/Tank Cradle, Right Tiedown Bracket

September 28, 2010

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A few days ago I had the circular saw out, and I saw (pun intended) a 16″ wide piece of 3/4″ MDF sitting around, so I took a quick look at the plans, and decided that 16″ x 16″ might be a good starting point for the leading edge/tank assembly cradle.

The plans (second picture down) show 13″ x 15″, but I’ve heard that some people break the cradle at the thinnest point.

Anyway, it took me all of 30 seconds to cut the 2 big square pieces and the four triangular pieces also pictured.

Tonight, I pulled those out for assembly (a quick night in the shop).

16" x 16" cradle walls, with 4 triangular supports.

Van's wants you to mount them on a 36" long 2x4, but I decided to go another route. Read on.

I used a thick magic marker to offest from a tank rib (room for pipe-insulation to protect the skins).

After the cut.


After the cut. (Déjà vu)

Tada! (Déjà vu)

After both were cut out with the jigsaw, I laid (layed? Em, help me out here) the tank rib into the cutout to make sure I had offset the cuts enough.

Looks good to me.

So, here’s an expplanation of my “alternate route”.

Because Van’s specifically states that this just helps in assembly, and is not an alignment jig, I decided I didn’t really need to take up a lot of space with a 3 foot wide cradle that would undoubtedly get in the way. Instead, I am making the two halves of the cradle independently, and will use them (approximately 3 feet apart). I also figured they would be stable enough with one of these triangular pieces on each side, which they were.

I predrilled the cradle, but not the gusset, and it cracked as I assembled with some coarse-thread drywall screws. Bummer (I never thought I would put a picture of my crack on the internet.)

For the other ones, I pre-drilled the gusset, too.

After everything was all said and done, I am pretty happy with them (damn crack!).

I need to grab some pipe insulation to protect the skins.

Best part, they nest nicely for storage before (and after) use.

Then, I looked around for something I could get done with the half hour of attention and “eyelids-open” time I felt I had left.

I shot a quick coat of primer on the right tiedown bracket (and spacers), and then waited for the first sides to dry before flipping them over and hitting the other side.

While the whole thing dried, I needed something else to do, so I grabbed the  T-715 Anti-Rotation brackets (which come all connected like the old plastic models used to. Remember you had to use a pocket knife to cut off the little tabs after bending and twisting one model piece from the rest of the pieces.)

Anyway, after getting them apart, I edge finished all four on the scotchbrite wheel. Maybe 10 minutes, and for the record, I am going to log this time under Spars, because I’m waiting for the tiedown brackets to dry. I don’t feel like adding an entry under tanks just yet.

When it is years and years from now, and you ask me how my hours it took me to finish my tanks, and I say “xx hours,” remember to add 10 minutes to that to get the real answer.

Edge finished anti-rotation brackets. (How do I edge-finish the inside edges of these? Hmm.)

Okay, now that the tiedown bracket is dry, let’s find those AN426AD3-7s – HOLY CRAP THESE THINGS ARE LOOOONG!

Whoa. Long rivets.

4 of 8 rivets set (squeezed).

Tada! (That's three "tada"s today. Aren't you lucky!?) Don't forget the nutplates on the other side. I almost did.

Oh, and by the way. Don’t prime and then wait 10 minutes for things to dry, the primer really hasn’t cured, and it will scrape off with a fingernail. After waiting 24 hours, or better yet, a few days, this stuff gets rock solid. I need to remember that.

I shot another coat on these after they were riveted. I was too ashamed of the first coat to take a picture. Sorry.

8 rivets and 1 hour. 0.5 in “Wing” and 0.5 in “Spars.” (I’ll put the log in both places. We’ll see how that works.)

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