Inboard Tank Attach Bracket

June 6, 2011

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Well, my order came in from Van’s today. Here are the goods.

It's like Christmas, but in June.

First up, a W-408-1R, NOTCHED NOSE RIB. Turns out, I ruined the other one by not making sure it was all lined up prior to drilling. I have a good idea on how to make this one work out, so stay tuned.

Also included in this order, my flop tubes, and some snap bushings, which I needed to order due to all of the holes I drilled in the wing ribs. (Oh man, now I want a steak.)

Leading edge rib, flop tubes, and snap bushings.

Then, the proseal (black death!), fuel tank leak test kit, and 25′ of black corrugated tubing that should fit nicely in the holes I drilled in the ribs (see steaky link above).

Black tubing, proseal, and test kit.

Even though I REALLY WANTED to break out the proseal and start slathering it all over my workbench, airplane, hands, clothes, and face, I decided to wait until my popsicle sticks and syringes come in from amazon.

So tonight, I decided to work on the right inboard attach bracket.

After studying the plans, I grabbed the AA6…I’m not going to type out the part number. See the picture below.

Yup. That's it.

(Insert silence here where I tried for 10 minutes to figure out what R1 is.)

I’m really sorry to admit this, but I started scouring the internet. Googled “VAF R1 TANK ATTACH BRACKET” and “R1 NOTE DWG 16A VANS RV-7.”

To no avail.

Then, someone’s build site (can’t remember who), admitted that they spent 10 minutes and some google searches trying to find out what the R1 stood for before they realized that it wasn’t a note, it was RADIUS=1 inch.

Duh.

Okay, I’ve got some lines drawn.

Whose cute toes are those?

I think that is T-410 on the top of the picture. I used that to trace mirror images on the 2" side.

Then, I pulled a can of OFF from the shelf and used it to make a 1" radius circle. Then, connected the tangents after drawing a 1/2" line along each side of the bottom. (The drawing is half scale, and it was 1.4" on the drawing.)

After some sawing, I for some reason lost interest and broke out some of the snap bushings.

Two of the smaller size (SB375-4), and one of the bigger size (SB437-4).

Sweet. These will work perfectly.

Nice.

Umm, who took this redundant picture?

Okay, back to sawing.

Hmm. This turned out to be annoying with the jigsaw. Maybe I need a bandsaw.

Done.

Insert about 30 minutes of deburring on the scotchbrite wheel….

Deburred.

So, then I put it in the nose of the inboard rib, and admired how nicely it fit. (Actually, it still needs a little trimming around the edges.)

Looks good.

Okay, I didn’t do a good job of taking pictures here, but basically, I drew a line 1 and 1/16″ back from the tip of the rib, and then drew a line parallel to the front edge, but 2 diameters of the final rivet size (1/8″) away.

Here's where I got the 1 and 1/16" from.

Then, I marked and drilled 5 of the 6 rivet holes, along with the center hole, which is the pilot hole for the 9/16″ hole that the flop tube fitting will fit through.

confused?

Here's a better picture. 5 plus the pilot drilled, and I've laid in the AN nut to see where I can put the sixth (marked) without rivet head interference.

This is me trying to figure out what size hole I’ll need for the fitting.

0.563? What fraction gives me 0.563?

Obviously 8/16″ is 0.5 and 5/8″ is 0.625. Let’s try 9 divided by 16.

Wuhoo!

Apparently I don’t have a 9/16″ bit, but I did work my way up to 1/2″ and then lay in some AN470AD4-7 rivets so I could show you my good spacing.

How's it look?

Here's the other side.

1.5 hours. Still need a 9/16″ bit, but that won’t stop me from getting into the tank stiffeners, drain flange, and filler cap soon.

I’m actually looking forward to it. Maybe this week.

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Posted by Andrew

Matchdrilled Right Tank Ribs and Baffle

May 26, 2011

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Not many pictures tonight, but I did get the tank matchdrilled.

But first, I got some things ordered from Van’s today in preparation for the tank sealing process:

  • 60 x BUSHING SB375-4 Snap Bushings, 3/8 (1/4)
  • 1 x DUCT NT 5/8-25 Nylon Conduit
  • 30 x BUSHING SB437-4 Snap Bushings 7/16 (1/4)
  • 2 x IF-4/6 RV-4/6/6A/7/7A/8/8A Wing tank flop tube
  • 1 x MC-236-B2 Tank sealant with accelerator QUART KIT
  • 1 x FUEL TANK TEST KIT Fuel Tank Test Kit

Of course, once I placed the order, I remembered that I buggered up the inboardmost rib of the right leading edge and needed a new one. I need to remember to order that one, and BEG Van’s to send it in the same shipment.

I decided to go with 2 flop tubes. (Flop tubes allow the fuel pickups to flop around in the tank, and therefore sustained inverted flight.)

One school of thought is that if you have two flop tubes and they get stiff, you could increase your unusable fuel (they don’t flop good no more) in either the upright or inverted attitudes. People therefore put one flop tube in and one rigid pickup. This means you have to switch tanks to your “aerobatic” tank before doing negative-g aerobatics. (How often will I do sustained inverted flight? Probably not very much.)

Anyway, I weighed the pros and cons, and came to the conclusion that the aesthetics of not having a single tank for aerobatics, and therefore a checklist item or a special placard, outweighed the possibility that after 10 years, my tube wouldn’t flop as floppily as it did when it was young.

Every couple years, I’ll open up the tanks and verify adequate flopitude. They are only $38, so it’s probably worth replacing them every 5 years anyway.

So, now that I’ve settled on duel flopicity, let’s get back to building.

I decided while matchdirlling, it would be easiest for me to do it while it was on the spar, so up on the spar the tank went.

(Be careful though, Van’s notes to matchdrill off the spar to avoid damaging the spar. This is really only a concern with the baffle holes (about the 10 most inboard ones). Take the tank back off the spar do matchdrill those.)

No action shots today, but much cleco-moving.

Back off the spar for baffle drilling.

Next up is fuel tank stiffeners, then a lot of prep before assembly of the fuel tanks.

1 hour.

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Posted by Andrew

Started Banging Rivets on the Right Leading Edge

April 22, 2011

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OH MY GOSH!

ANDREW’S

BUILDING AGAIN!

Well, even though my last post said I was getting back into the mood of airplane building, it’s been almost a MONTH since I spent time on the project.

Yikes.

Anyway, I had a day off today, and I managed to spend a couple hours in the airplane factory.

Let’s see if I remember how to take and post picture.

After a little garage cleanup, I got the right leading edge out and got back to deburring all of the holes. I think deburring took about 30 minutes.

My hand hurt after deburring all of these. I need to deburr more often.

Once done, I took the cradles off the skin and opened her up to do some scuffing.

I haven't totally finished the leading edge light installation, but I can do that after the ribs are installed.

Then, I broke out the c-frame and started dimpling. This actually takes awhile, because you have to be careful not to punch any extra holes in the skin.

Even though I can reach these dimples with my squeezer, I think you get better, crisper dimples from the c-frame.

Here's me doing the forward-most hole in the top of the leading edge skin.

AHHHHHHHH!

THE DREADED

FIGURE-8!

Well, after 242 hours, and thousands of dimpled holes, I finally joined the club.

To tell you the truth, it’s really not that noticeable, except for the fact that it is on the top of the wing (AND YOU’LL ALL NOTICE IT)!

Anyway, I used some flat sets and pounded it flat, then filed it down a little, and dimpled the primary hole.

Here's the extra dimple pounded flat.

And the orginal hole dimpled. still needs a little filing here.

I could throw a fit and order a new leading edge from Van’s, or I could just build on, and cover this with filler and paint.

(I don’t think I can polish the wings anymore.)

Well, in the interest of building on, I decided to do a little riveting today. I had a couple ribs prepped (my legend: R2 and R3), so I got them prepped, primed, and clecoed in place. (Making sure to cleco one rib on either side of those so the leading edge was perfectly straight.

Here are the ribs clecoed in place.

Of course, I use my normal tape-over-each-rivet-head trick to minimize scratches, dings, and marring.

I shot and bucked every other one (no mistakes) and then replaced the clecoes with rivets, moved the tape over, and finished the row.

(Needless to say, I started with the bottom of the leading edge, so any mistakes due to out-of-practice riveting wouldn’t be so obvious.)

Gratuitous shop head shot on the lower surface of the first rib.

Gratuitous shop head shot on the lower surface of the second rib.

Wash. Rinse. Repeat. (Crap, I meant flip, cleco, rivet, repeat.)

Gratuitous shop head shot on the upper surface of the first rib.

Gratuitous shop head shot on the upper surface of the second rib.

Umm, did we not have enough shop head shots today?

Andrew, STOP TAKING PICTURE OF SHOP HEADS.

Here’s the “club” rivet. I think I’m going to leave it like this, and just watch it for cracks, but someone will probably tell me I need to drill this out and replace it with some other solution. We’ll see.

(big. depressed. sigh.)

Seriously, I need to control myself with this camera.

Oh, and I was having trouble counting rivets today, which was weird.

So I just started writing them down. Can you guys check my math?

3 hours, 58 rivets, 1 figure-8. Boo.

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Posted by Andrew

50% Clecoed Right Wing Skins

February 7, 2011

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Well, my order of clecos showed up. It was in a pretty small box on the front step, but that little tiny box was deceptively heavy.

After unpacking the box, I noticed that this bag is a bag of 500 clecos.

They actually opened the bag and removed 100 clecos to get to my order of 400. I wish I had known, I would have ordered another 100 just to save them the trouble of counting them all out.

Bag o' clecos!

Anyway, I emptied them into my (now empty) silver cleco bin (an old tupperware container).

I even left the automatic flash on so they would shine a little extra for you.

These things are brand-spanking new. And made in the USA.

U.S.A!

Some people on the forums were pointinng out that I got a heck of a good deal at $0.35 each, and they suspected they were not going to be the new, USA-made clecos.

Well, these are new.

This next picture shows a few of my different kinds of clecos. From left to right:

1) Clekolok USA, new today (from Innovative Tool Supply)
2) Kwik lok USA, purchased about a year ago (from the Yard)
3) Kwik lok USA, purchased about a year ago (from the Yard’s used bulk area)
4) Unknown, purchased about a year ago (from the Yard’s used bulk area)

New to old, they all work the same. I haven't noticed any degradation of holding power.

Anyway, I then spent the next half hour sticking these new clecos into my right wing.

Based on a conversation with Bill Repucci, I’ve decided to mitigate all of my alignment concerns by just 50% clecoing the wing. (50% meaning every other hole, as opposed to 25%, which would be the Van’s suggested everth fourth hole.)

I have to admit, that thing is rock solid now.

The right top skins with a cleco in every other hole.

I looked at my new cleco stash and realized I was about halfway through them already.

Crap... those went fast.

After another half hour of every other hole clecoing the right bottom skins, I reached in my cleco bucket and only had two clecoes left.

Uh oh.

Darnit.

I almost made it with 600 clecos.

There are a few missing clecos along the rear spar (towards the bottom of the picture).

When I get to that area during matchdrilling. I’ll just move some of my clecos from other areas.

1 hour of clecoing fun.

Contrary to what other builders have to say, my hand isn’t that tired, and I therefore don’t intend on spending $200 for a pneumatic cleco runner. Take that!
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Posted by Andrew

Riveted the Right Rear Spar to the Main Ribs

January 23, 2011

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Well, today was a crappy day. I had mucho problems with riveting the right rear spar to the main ribs.

I’ll walk you through what happened.

I started with the inboard side of the spar. The plans call for an AN470AD4-8 rivet. As you can see below, this is a little for a good shop head.

...AD4-8.

Here's an ...AD4-9 rivet. This looks better.

After some gymnastics with my good squeezer, which only has a 4″ no-hole yoke on it, I realized that I needed the holed yoke, and therefore needed to use my economy squeezer. Bummer.

(Back in the empennage, I stopped squeezing AD4 rivets altogether because I kept messing them up; the economy squeezer just didn’t have enough oompf.)

Anyway, I managed the wingwalk rivets with the smaller squeezer. Here’s 9 rivets squeezed.

I couldn't reach the top-most rivet in 3 of the 4 wingwalk ribs. (The other open hole in each of the rib attach points needs to wait for the flap brace.)

I moved my way outboard from there, two rivets in each rib.

Halfway there, I bent over both of the rivets in the aileron pushtube doubler area, and drilled both of those rivets out. Then, the aileron gap seal switches “open” rivets (compared to the flap brace) so of course I set a two rivets there that had to be drilled out.

When I got to the end, I noticed things weren’t lining up very well.

Duh. Forgot to dimple the aft side of the outboard rib.

That's better.

I still couldn’t reach the one rivet (shown on the left here), but I got the other 3 set properly.

The apparent gap between the two flanges isn't really a gap, its just the shadow.

Let me bring you back to the very first rivet I set. The camera is upside down here (so the part is right side up).

The upper, leftmost rivet bent over (it was the first one I set with the economy squeezer). After drilling out, the hole was englarged.

With only slightly enlarged holes, sometimes you can just squeeze another rivet (a little longer this time) and it will expand to fill the hole nicely.

This is after setting another rivet.

This one did not properly expand, and by the time the shop head was formed, it kind of formed in the hole.

Hmm. I know this is a critical piece, so I’m going to have to call Van’s and ask them what the best course of action here is.

I’m hoping I can step up to a AN470AD5-9 rivets, but I’ll need to drill the rivet and hole out to 5/32″ and I’m worried about edge-distance in the up direction.

We’ll see what the guys at Van’s have to say.

January 31st update: Ken S at Van’s wrote back.

A 5 rivet should work ok. If you can fill the hole with the original rivet, that’s ok too –even with
a slightly undersize head. Just be sure that the rivet engages the entire circumference of the
hole.

Alright. I’ll have to add AN470AD5- rivets to my next order from Van’s or Aircraft Spruce. In the meantime, I’m going to keep working on other stuff.

U-G-L-Y, you don't have no alibi, you ugly! {clap, clap} You ugly!

1.5 hours and 28 stupid rivets set (my arms are tired from the economy squeezer); 8 of those drilled out.

I’m going to have to buy a new yoke ($$$) and probably do some surgery on the offending rivet in the last picture.

I’m stopping this post and starting another one (click next below) because I moved on to the skins. I really needed to end on a good note today, and the skins actually did the trick.

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Posted by Andrew

Left Spar Arrived from Vans

September 21, 2010

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I was home at lunch today randomly (so I could pick up more propane for tonight’s planned grilling session), when I passed a FedEx Express van.

Hmm. That’s weird. Last Thursday, I got an email from Jessica at Van’s saying they had shipped my left spar back to me via FedEx Express, and it was supposed to arrive tomorrow.

Using some critical thinking skills (and the realization that I had NOT been diligently tracking my package over the weekend), I figured the FedEx Van was in the neighborhood for me. I flipped around and followed the driver back to the house. (It’s amazing how incrementally excited I got after each turn back toward the house.)

Anyway, the spar arrived, and it was, in fact, a new, undamaged spar.

Came in its own cute little crate.

No damage!

I didn’t post a lot about my left spar before, because I wanted to see how it would end up before posting to the world, but here’s a quick summary. My left spar, as received in the wing kit, had a pretty small dent in the lower inboard flange. While it was probably airworthy, I was concerned that I didn’t know how much margin on top of limit load I had lost (if any). Also, would there be any residual stress in the area of the deformation, and what long-term stress cracks should I anticipate based on this dent? Do I have to disclose this damage if I ever sell the airplane?

(Background: The airplane is designed for +9/-6 Gs, and the limits placed on the airplane are +6/-3 Gs. The idea is that a spar with damage might really only be good for 8.8 Gs now, or maybe 8.5 Gs (or, admittedly, 8.999 Gs…it was a really small dent).

(Philosophical question: If you could quantify the new margin, and a spar was good to a known 8.5g instead of 9g, and you were still limited operationally to 6g, would you accept it? I still don’t know the answer to this. I think an 8.5g spar would meet the design intent of the airplane (but Andrew! what about 8.4g?!), but what if I accidentally over-g the airplane, something breaks, and I am falling helplessly to the ground. With a “perfect” spar, at least I know it was all my fault. With a dented spar, I’d be cursing Van’s the whole way down.)

(Dear Mom. There is no way I’ll ever over-g the airplane. Stop worrying. It was just for discussion purposes.)

If we could quantify what I’ve lost if I continue to build with the damaged spar, I may be okay to proceed with enough residual margin, but I have a hard time putting a spar in my airplane knowing it isn’t perfect structurally and not being able to quantify what I’ve lost. For the record, I’m an engineer… this has nothing to do with the small scratches and scotchbriting everyone has on their spars. I’m talking about material deformation.

Anyway, Gus and I talked (about loads…bending, drag, torsional, etc., but I’ll leave that out of here for now), and they really don’t have the capability to do an analysis on a spar flange like that, so he agreed to send me a replacement spar if I could send the other one back. (They can do an ultimate load test on a completed wing, just for future trivia.) Luckily, since this was shipping damage, ABF has picked up the shipping tab. (ABF customer service was less than optimal).

I feel a little guilty about standing ground about the damaged spar, but I think some of that has to do with work (if a spar had come into work like that, we would have either immediately rejected the part and sent it back, or performed enough engineering analysis to deem it acceptable as-is or with a repair). I want to be able to take my airplane to +6/-3 Gs and not always question whether my margin is the same as everyone else’s.

(I’ll leave out the more philosophical discussion about whether the margins on top of the posted limits are equal given the widely-ranging construction practices and skills that appear to be out there in the build community. I have to assume the airplane is designed to fly with plenty of margin after being built by a below-average builder, but can still pass Tech Counselor and DAR/FAA inspections.)

Ultimately, Van’s did a great job managing my concerns and communicating quickly and effectively about the whole problem. I really do appreciate their commitment to customer service, and their willingness to listen to my engineering concerns about the defect.

Thank you, Van’s.

Now.

Back to building!

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Posted by Andrew

$6.48

June 22, 2010

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After getting stung by a wasp two times in the last two days trying to mow the lawn in the backyard, I gave up (shows determination and perseverance, huh?) and retreated to the comfort of my garage for some airplane work (the floors can wait until tomorrow).

Back to the tab. Before I do any more cutting on the elevator, I want to get the tab hinge drilled so I know exactly where the outboard edge of the tab will swing. I am doing this before they really tell you to in the directions (the directions have you actually finish the elevator, then start working on the tab.

Anyway, you are supposed to draw a line 1/4″ from the loop edge of the tab, and first matchdrill that to the tab. (I started with the elevator side, which eventually bit me in the ass. Read on.)

I decided to mark both sides with the 1/4" line. Hmm. Doesn't look like there is going to be a lot of edge distance.

Then, I took the hinge apart (you can see the hinge pin in the next photo) and clamped the elevator side to the elevator, lining up my 1/4″ line in the first prepunched hole, and aligning the first hinge loop where I thought it looked good (making sure this fit with the plans).

Hint: If you take apart the hinge, you can easily clamp the hinge half to the elevator (and tab, with the other half).

Next, I lined up the outboard side. This tab hinge is nice and square with the edge, and with the holes.

Let’s drill!

Here are 6 holes drilled (I'm working inboard to outboard).

All done with the elevator side.

Next, I reassembled the hinge and spent a few minutes just kind of getting everything lined up.

I wish this were the final product, but this is just me mocking things up before drilling.

With the greatest of coordination, I managed to hold a straight-edge against the inboard edge, line up the inboard pre-punched hole with the 1/4″ line, and line up the trailing edge of the tab with the trailing edge of the elevator, AND take this picture. Boo-ya.

Looks good so far.

Then, I drilled the inboard hole. The inboard side is perfect. (Can you tell that some other part may not be by the way I phrased that?)

If you look closely (lower left corner), you can see that the tab trailing edge is further aft than the elevator trailing edge.

I was pissed. I lined up the hinge with the elevator edges and holes, and with the tab edges and holes. This means that either the elevator or the tab isn’t perfectly square.

I thought about just moving the tab forward, but then there would be slightly different distances between the skins from inboard to outboard. I measured it…it would have been about 1/32 difference. No one would have noticed except for me.

But…I can’t leave it alone. I’m going to reorder the hinge and try again. This time, I’m still not going to follow the directions. If you make the hinge perfectly square to the tab, it’s going to be off on the elevator side. I’m going to have to split the difference between both by first clamping the tab in perfect position, then clamping the hinge in place and matchdrilling a few holes.

Admittedly, I should have followed the directions by starting with the tab edge, but it wouldn’t have mattered, it still wouldn’t have been a perfectly square hinge line after I was done.

The tab hinge is AN257-P2 according to the materials list in Section 4, but the part shows MS20257-2.

I also think, given my edge distance worries (must be okay because it is per the plans? I don’t know), I am going to order the MS20257-3 (or AN257-P3, which is 1 + 1/4″ wide instead of 1 + 1/16″). I checked with Van’s, and they want $9.70 (plus $4 handling, plus $12 shipping or something) for an 24″ piece of AN257-P3.

I checked aircraft spruce, and they wanted $4.75 for a 3′ piece and $1.73 shipping via USPS.

Which one do I choose?

Duh. $6.48 for my first re-ordered part. Bummer. (It’s better than a $60 elevator skin, though!)

Here are my edge distances.

I love this kind of building. Thinking, playing, mocking up, etc. The normal matdrilling dance gets old…this is the stuff I really like.

1.0 hour tonight. Frustrating, but fun.

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Posted by Andrew

Ordered Wing Kit

May 14, 2010

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Well, I did it.

At 10:35am PST this morning, I sent in my wing kit order.

”]

Given the 13 week lead time, it should arrive sometime in…(counting)…August.

Don’t worry, I still need to do a few things before it arrives:

  • finish up the right elevator
  • start and finish the left elevator
  • install the empennage tips
  • clean up some edges
  • build wing jigs (not jigs…”stands”)
  • paint garage ceiling
  • epoxy garage floor (maybe)
  • build garage shelves in the same manner as workbenches
  • buy and install wood floors on first floor (1000 sq ft.)

I think I can keep busy for a couple months.

Later Friday night, I heard back from Barb.

Andrew, you’ll have about 8 weeks to decide how to ship your kit, but you
will need to let me know before your ship date if you want to us any other
method other than by my normal freight company.  Thanks for the order.

Then on Monday morning:

Andrew, it will cost about $359 to ship the wing kit to your door by ABF.

Now I need to contact Tony Partain to get an estimate through him.

June update:

Apparently, if you order the deluxe locking fuel caps, Van’s will credit you for the caps they normally send with the kit. That turns $210 deluxe locking fuel caps into $150 deluxe locking fuel caps. Wuhoo!

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Posted by Andrew

Tools from Harbor Freight, Van’s

March 3, 2010

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I didn’t get any work done on the airplane tonight, again.

I did manage to stop by Harbor Freight and receive an order from Van’s. Just for effect, I’ve taken a picture of the only two adjustable wrenches I own.

So sad...

I found a coupon for these adjustable wrenches, except when I got back home, I saw the coupon didn’t take. Is it work the $2 to drive all the way back there? Probably not.

OH YEAH, look at these bad boys! $10 from Harbor Freight.

Next, I grabbed a new utility knife. I have a couple from 1963 or something, so this should be a good upgrade.

nice blue locking utility knife.

Here’s my modest order from van’s. I had drilled out a lot of An470AD4-6 rivets on the horizontal and vertical stabilizers, and I had to use AN426AD3-3.5s instead of AD3-3s on the rudder stiffeners, so I ordered 0.1 lb of each to kind of replenish my supplies. Also, there is the 3.5 oz container of fuel tank sealant to use on the trailing edge of the rudder. It’s coming up, you know.

The Van's order.

Finally, at HF, I noticed this furniture dolly. It’s not very big, but for $7, I figured it was worth it given that it would take me more money to buy the supplies to make one.

A furniture dolly for some future aircraft-related need.

I need to actually create some aluminum dust soon. It’s driving me crazy seeing the rudder skin with the beautiful stiffener riveting just sitting on the workbench, all lonely and such.

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Posted by Andrew

Started Rudder – Stiffeners

February 16, 2010

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Well, with the vertical stabilizer safely in the airplane storage room, it’s time to get started on another part. Next up, the (infamous) rudder. There are a lot of steps on the rudder that give a lot of builders a lot of trouble. I am confident, but will continue to use other sites on a daily basis before doing any work that evening. That’s worked out well for me so far, so I’m going to keep at it.

First thing’s first, the ceremonial plans change. I still keep the plans on my second workbench. Maybe someday I’ll find a place to actually hang them up.

Drawing 7. The Rudder. (Cue dramatic music.)

I spent a little time trying to figure out whether I will do the stiffener-to-skin dance on both sides at once, or just one side. You can see below that if I had another longer piece of MDF and maybe took my vise off the bench, I could set the skins on opposite corners and maybe do them at once, but I think I’ll just do one at a time, making sure I can reuse the holes I plan to drill into the table. (Drilling, and then clecoing, the stiffeners to the skins all the way into the table will allow me to keep everything very steady. Sounds like a good plan to me, and is pretty much standard given that Van’s suggests doing so in the construction manual.)

I'll have to do one skin at a time. I don't want to get too crowded, and I am not overly concerned with building efficiency.

First step in the manual is to start on the stiffeners. I fished out the bundle of stiffeners (there are two bundles, one set for the rudder, and one set for the elevator) and studied the plans.  For the back side of the stiffeners (with the shallow angle on the right side of the picture below), these are the final cuts, so I need to be careful. For the front side (you can see a little of the front of a stiffener on the left in this picture), only 2 of the 16 stiffeners will be to full length, so the other 14 can be rough cut until I can mark them to final size per the note at the tot of this picture.

Stiffener Trim detail, drawing 7.

Next, I headed inside to sit myself down at the table so I could watch the UNC vs. GT game. I know some of you are panicking right now, but please calm yourselves. While it appears that my winerack is empty (OH MY GOD, NOOOOO!), that is really our third winerack. Rest assured that our two primary wineracks are stocked satisfactorily.

Is that an empty winerack? Don't worry, the hooch is stored in another rack.

Anyway, here’s the stiffener bundle I’m about to break open.

R-915. (I can't think of a funny caption this morning, so all you get is the part number.)

I broke open the bundle and started snipping from center hole to center hole. After a few stiffeners, I started biasing the cuts to the sides of the holes, but only where I was sure that I was going to have to remove more metal later.  Here you can see that on the top part of the cut, I’m lined up with the left side of the slot.

Snip snip.

I included another picture of the angle cut for the front end of the stiffener. Remember, only two of these cuts are for real, as the next step is to chop off varying lengths of stiffener from the front to match up with the pre-drilled holes in the skin.

Snippity Snip snip.

Here’s a rough cut for the front end. See how I am going to have to remove more metal because of the notches. Might as well get closer on the first cut. That’s why I started biasing the cuts to one side after the first few.

The front end of the first stiffener.

First 8 front ends done.

Yikes, those are going to need some edge finishing.

All 16 stiffeners’ front ends done.

That's a spicy stiffener.

Next, I used an admittedly fat sharpie to draw the required cut lines on the aft ends of each of the stiffeners.

Lines drawn, back to snipping.

And here I am using the snips to cut that longer line. Snips aren’t perfect for this task, since they bend the metal, but if you work them correctly, they will only bend the piece you are cutting off. There is kind of a rocking motion you have to feel with each cut. You’ll get it when you try.

Snipping the aft end.

Here’s the first one, done.

I'm a little camera happy today, don't you think?

Then, I finished up the other 15, and was left with these scraps. If I had even the slightest hint of an artistic bone in my body, I would make some comment about how these resulting spirals are king of cool. But I don’t, so I won’t.

Scrap from the latest cuts.

All 16, ready to be devinyled.

Done with those cuts.

Starting to devinyl…

This is going to take forever.

I’m glad I did the devinyling inside. When the vinyl is warm, it comes right off.

Holy crap that's a lot of blue v-......WHOSE TOES ARE THOSE AND HOW DID THEY GET IN THE PICTURE!?

Next, I headed outside to put everything away, but couldn’t resist setting the stiffeners out on the skins.

I'll need to trim some of these, don't you think?

For now, I just drew a thick marker line along the front spar holes. If I cut along these lines, they will still be too long, but at least now I can figure out which hole will be the most forward hole and then use the plans-suggested 1/4″ measurement to draw a nicer cut line.

8 of the 16 stiffeners, ready for final cutting.

One hour of camera-happy warm environment work tonight. Sorry about your bandwidth.

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