Drilled Right Flap to Wing

January 17, 2012

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Warning: My blog is not a drinking game.

But, if it were, and you had to take a drink every time I logged some build time…

You would not be very drunk.

Hello, everyone. In case you forgot (has it been two weeks?), I’m Andrew, and I’m building an RV-7. Today, I actually got a lot done on the airplane.

It was really only a few drilled holes, but they were important for two reasons.

1) Everyone freaks out about drilling the flap to the wing, and

2) I drilled the flap to the wing prior to the flap actually being riveted together. I know it’s out of order, but I made the decision that the flap was super-sturdy and aligned when it was clecoed together.

(Also, it’s late, and I’m at the step where I need to make a lot of noise with the c-frame, so drilling was quiet by comparison.)

Let’s get to the pictures (and video!!!!).

First up, I wanted to knock out some of the smaller tasks that need to be completed before moving on to priming and assembling. First up is to cut down one of the spar brackets to final size.

I wish I had take a picture of the original piece, but here’s after the cut.

I'm still using my jigsaw for these.

After some scotchbriting.

Then, I moved on to dimpling the spar (I had deburred the holes a few centuries…I mean weeks ago.

Dimple holes. No biggie.

Also, I countersunk the appropriate holes for the nutplate around the flap rod-end attachment hole.

Standard flush rivet in the background, an oops rivet up front.

Here’s where I made a big decision. I was looking for something quiet to do, so I decided to cleco up the flap and just set it on the wing.

First, I needed to get the lower outboard skin clecoed in place.


Then, I just clamped the flap in place.

Whoa. Looks cool. Like a real wing!

At this point, given the sturdiness of the flap, I decided I could drill the flap hinge to the wing. Even if I totally hose it up, all I’d have to do is order a new flap hinge. (I can order that along with my new RUDDER, which I still haven’t accepted as needing replacement yet. What was that….a year ago?)

Anyway, let’s just clamp everything in place and see if it still makes sense.

Looks like I need 1/4."

Two 1/4″ drill bits, two Popsicle sticks, and two clamps later, I had a flap ready to be drilled.

For the record, this was not the first, nor the last, of the many attempts at a) a good picture, and b) aligning the trailing edges.

Looks pretty good though. Not perfect, I need better alignment along the trailing edge.

For most of my alignment, I used my 4′ level on the trailing edge, then used my iPhone level app to get down to the degree.

Here I'm making sure the transition lines up, then I'd move the level to the flap, measure the absolute angle, then move it to the aileron, and compare the absolute angle.

After about 10 iterations, I drilled the first hole.

Sorry about the blur. The good news is that it's still making sense and aligned.

After working a little down the line (Drill, cleco, measure, measure, measure. Drill, cleco, measure, measure, measure), I stood back to take this picture.

Looks straight to me.

Almost forgot, another one of the measuring tasks was to measure the gap between the flap skin and the lower wing skin.

0.2965" the whole way. Can't get any better than that.

A little interesting note…the flap brace didn’t perfectly line up with the lower wing skin, so I had to improvise a little.

I didn’t want to be matchdrilling the hinge through two other holes that didn’t line up, so I wanted the whole flap brace perfectly in position prior to drilling. I grabbed the smallest -AD3- rivets I had and stuck them in every other hole to act like clecos (I could have use clecos, but that pushes the hinge away from the backside of the flap brace.)

This kept my skin and flap brace holes aligned all the way down the row. As I’d get close to the next rivet, I’d just pull out the rivet.

This worked great for me, but your mileage may vary.

Of course I forgot to take a picture when I was done. I did “lower” the flap all the way to measure, and then mark, the three hinge eyelets I will be using for future hinge pin access.

I've marked them for future modification for the hinge pin insertion, but you'll have to wait another day for that.

Here are some of my “after” pictures.

Looks straight to me.

Looks so good.

Like a real wing.

I was so excited about it, I had to get a video.

So, 2 very productive hours. I’m sure some of the builders out there will insist that all will go to hell after I rivet the flap together, but I don’t think that’s going to happen. So far, all the match-hole kit parts are lining up perfectly, and the clecoed flap is very sturdy and true.

Now, I need to get back to prepping the flap for final assembly. But first, I need sleep. Goodnight.

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I Hate Drilling Stiffeners

August 15, 2011

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I’m still trying to nail down a good time for continued wing skin riveting, so in the mean time, more ailerons.

But first, a little taste of how I like to walk the dogs. Or rather, how they walk me.

In the same vein as last night, I’m not really a big fan of drilling stiffeners. Maybe it’s because I’ve done it on the rudder and both elevators, but it’s just kind of boring.

You can tell it’s boring by my lame pictures tonight.

After drilling some stiffeners, a boring picture.

Halfway through the 32 total stiffeners, one of my #40 drill bits broke. Boring picture.

I labelled each stiffener with the aileron (right or left), side (upper or lower), and then 1 through 8 from inboard to outboard.

After about 45 minutes of that, I decided a nice small (15 minute) task would be to knock out the edge finishing.

Did anything assist me in that decision? Yes.

A pretty bad cut on my knuckle from dragging it across a skin edge. Ouch. (So far, this project has cost some blood and sweat. I’m sure the tears are on there way…)

All the edges edge-finished, and some nice round corners.

Here are both aileron skins and the four piles of stiffeners, all matchdrilled.

I may be done with drilling stiffeners. Who knows.

1.0 Hours. I bet tomorrow’s post is called “I Hate Deburring and Dimpling Stiffeners.”

(Actually I don’t hate deburring and dimpling stiffeners. I can do it inside, where the A/C is nice and chilly.)

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I Hate Making Stiffeners

August 14, 2011

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After last night’s bummer of a screw up (mis-drilling the aileron spar reinforcement plates), I woke up in a cold sweat.

I thought I was going to have to order four more little plates, just to pay some ungodly amount of shipping from Van’s to here.

Then I rememberered the “Trim Bundle” than Van’s sends you. I think there may be some 0.040″ in there.

Sure enough (after measuring, finding some 0.045″, then taking the blue plastic off, and seeing that it was really 0.040″), I had something to continue working on the ailerons.

I went ahead and marked some 0.032" that I found, as well.

After some measuring, marking, and trimming, I have 4 new pieces.

Old and new.

Instead of clamping these to the spar, I decided to just use the old pieces to matchdrill the new ones.

I've clamped the new pieces under the old ones, but in the OTHER orientation.

After some drilling, scuffing, edge-finishing, and marking, I had four new reinforcement plates.

Like new.

I clamped them to the spar, and marked the appropriate holes for countersinking.

There are two holes on the outboard end of each spar, too.

After that, I looked around, and figured there was nothing else to do except start some stiffener fabrication.

I hate making stiffeners (see title of post for emphasis). It takes forever, there are pieces of aluminum flying everywhere, your hands get cut up, but, it’s necessary.

After about an hour of cutting, filing, snipping, edge finishing, and scuffing, I have 32 beatiful stiffeners to go into the aileron skins.

8 on each of the upper and lower surfaces of each aileron.

That sucked, but as long as I can salvage the rudder stiffeners, I think those were my last stiffeners!

2.0 hours.

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Right Tank Stiffener Prep

May 30, 2011

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So, among other horrible things that happened to me today (leaky toilet, Sopranos DVD that kept skipping, ground turkey burgers, which were delicious, except it was actually chicken), and dogs that are freaking out at the neighborhood fireworks, I managed to drop my ONLY set of cleco pliers behind my workbenches.

“But Andrew, you have both your workbenches on wheels,” you say?

Yes, except I still have the spar box, and it’s lengthwise under both workbenches, so I really can’t move either.

After a few minutes of maneuvering, I gathered up a few things I found under the workbenches.

I was wondering where my first-aid kit went.

Anyway, I spent about 30 minutes at the scotchbrite wheel edge-finishing my stiffeners.

After that, I got them clecoed into the skins (yes, I know I’m not doing them the same way as the elevators, I don’t think I need to drill them into wood this time).

I labeled them before continuing so I could get them back to the same spot when ready for final assembly.

Here, you can see 6A (aft) and 6F (forward).

5A anf 5F.

1A and 1F. I only show these because Van's cautions everyone to have enough room to the left of these stiffeners for water (contamination) to flow to the drain to the lower left. I think I've got plenty of room.

Then, I got to drilling. I went a little different route and drilled from the outside-in.

Lot's of clecos.

After drilling, I spent the last 30 minutes of my work session tonight deburring the holes, then scuffing just the bottom side (becuase that’s where the pro-seal will go), and finally dimpling the holes in the stiffeners using my tank dimple dies from Avery.

1st one done.

Wash. Rinse. Repeat.

All 12 complete.

All that’s left before actually breaking out the pro-seal is:

1) Cleaning these stiffeners up (along with the drain flange and filler cap)

2) Deburring, scuffing, dimpling, and cleaning the skin.

At that point, I can rivet the stiffeners, drain, and cap in. Then I’ll start into the ribs, but I’ll need to do a whole whole bunch of finishing on the ribs, too.

1.5 glorious hours of edge-finishing, drilling, deburirng, and dimpling.

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Right Tank Stiffeners, Z-Brackets, and Countersinking

May 27, 2011

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First thing, I have to give some mad props to Van’s.

If you remember from yesterday, I put in a web order with Van’s for some stuff. At the top of my list was that leading edge rib I messed up a few posts ago, and I FORGOT TO ORDER THE RIB!!!

Anyway, here’s how a short interaction with Van’s (e-mail):

Me: Good morning, Barb…[snip]…Is there any way you can add an item to my order? I need one of the following, copied from “the list”: W-408-1R, NOTCHED NOSE RIB 032, $23.80. If not, I understand…it was my error. But if so, thank you so much!

Within an hour (and definitely before normal business hours in OR):

Barb: Andrew, I have forwarded this on to our parts department who will download
the web orders this morning and get it added to your order.  Barb

Then, after about another hour:

Dear Andrew,

The part was added to your order as you requested.  I just caught it
prior to being shipped this morning.

Van’s order dept.

Oh man, Van’s is awesome. Also, I figured out from the charge that shipping (UPS ground) and handling from Van’s was about $15. Not bad.

Anyway, being a Friday, I was looking for something relatively painless to do tonight. I pulled out the T-711 bundle and started in on the stiffeners.

Here's the bundle.

I ended up getting all of the stiffeners ready, for both tanks. I’ll put the ones for the left tank away until I’m ready to do that tank.

Below you can see 3 of the four sizes of stiffeners. The fourth size is pretty small, and I left them out of the picture.

Three sets of long, one set of kinda long, one set of kinda short.

Lastly, I took off all of the vinyl. If I were smarter, I would have pulled the vinyl off before cutting them. It would have been a lot easier.


It was a little late to fire up the scotchbrite wheel, so I pulled out the right z-brackets and clecoed them to the spar. I spent a good five minutes staring at the plans to make sure I had them in the right orientation.

I'm doing this because I never matchdrilled the rear flanges of the interior ribs. The z-brackets and baffle are full-size holes, so I just need to run the drill through them with the flanges in place.

Drilling some holes.

Moved the clecos, drilled the other three.

Then, since I wasn’t too tired yet, I broke out the microstop countersink and started countersinking the skin-to-baffle holes. You do this so the baffle is easy to slide in place with the all pro-seal flying around. If it were dimpled, it would be harder.

Countersinking a skin this thin definitely leaves a knife-edge, but that’s what Van’s calls for here.

I’m planning on using the thicker tank dimple dies everywhere else, which should leave a little extra room for proseal underneath the rivet head, but I couldn’t bring myself to deepen these countersinks at all. We’ll see if it works out.

Looks good to me.

Much countersinking ensued...

A closeup, for those of you who are interested.

Anyway, it as a nice night in the garage. 1 hour, and getting closer to the black death.

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Prepped and Clecoed Right Tank Ribs to Tank Skin

May 25, 2011

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Well, tonight was fairly interesting. I pulled the right tank skin off of the spar (where I had been storing it using a few screws) and set it in the cradle.

Then, I fished out the right tank ribs from under my workbench and started fluting and edge-straightening them. (Luckily, I had remembered to edge-finish them on the scotchbrite wheel with the others a long time ago.)

Anyway, after fluting ribs 1 and 2 (the two inboardmost ribs)…

Not too exciting. 5 more to go.

While I was working, I kept thinking, “I should stop to take a picture…no…they’ll be okay with only a final picture.”

All 7 ribs ready to be matchdrilled.

Another shot.

50% clecoed.

Tomorrow, I’ll try to get this thing matchdrilled.

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Mucho Leading Edge Work

January 3, 2011

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Warning: This is a long post with lots of pictures. I’ll try to keep commentary to a minimum. (Oh, and I just took the pups for a run outside, and it was cold, so please excuse the typos…my fingers are still a little frozen.)

Well, today was a day off for me (New Year’s Day observed) where everyone else had to go to work, so I got a ton of work (on the airplane!) done. It was really cold last night (and today on our run…brrr), so as soon as I was ready to get out into the garage to work, I turned on my portable heater and turned right back around to go inside.

Hmm. I guess I can devinyl some leading edge skins while the garage heats up and I keep warm with coffee.

Here's the right leading edge.

Right leading edge upside down.

More right leading edge

Left leading edge, upside down. (That hole is the stall warning vane access panel. More about that later.)

Left leading edge again. (That small strip of devinyled leading edge on the left side of the picture is the stall warning vane rib attachment. Again...more later.)

That was about an hour of devinyling, so when I took my leading edge skins outside, it was not too bad temperature-wise. Thanks portable heater!

Note: I am working a little out of order. Technically, I should be prepping the main ribs for priming, then riveting those ribs to the spars, then setting the wing stand up, and then adding the leading edge. Since I’m waiting on some scotchbrite wheels for the rib prep part, I’m jumping ahead to the leading edge stuff.

Here, I’ve got all of the right leading edge ribs (except the inboard, undrilled rib) clecoed into the leading edge skin. Many people have trouble here, but if you follow the directions (which I kind of did), you start from the front end of the rib, top and bottom, and then you are okay from there. The biggest trick I found was to push the rib forward (towards the nose) as you are maneuvering the rib into place. I have long arms, so I could see the holes line up from the back, then reach around and stick a cleco in.

I like my modular leading edge/tank cradle. (No comments about my split triangular piece of MDF, please.)

Anyway, then I put the leading edge on the spar, and stood back in amazement. (Amazement at the size of the assembly, and that all the holes freakin’ line up! I know this is a prepunched kit, but still, everything just always lines up. Thank you Vans!)


The dogs must have sensed my excitement…they came out to see what was happening.

Ginger: "Shouldn't you have prepped and primed all of these ribs first?"

Jack (tentatively): "Whoa, that leading edge looks good, but I'm going to stay here...the concrete is cold on my paws."

After playing for a few minutes, they went back inside (it turns out they came out to ask me to turn on the gas fireplace….okay, okay, I will).

On to the left leading edge.

This is an awesome sight. It finally looks like I'm building an airplane in here.

After setting both leading edges on the spar (and securing them from beneath with some #30 clecos through the main spar), I noticed that the spar really needs to be straight and level to proceed, even though it’s not fully assembled yet.

So, even though I know I’m going to take this all down soon, I went ahead and leveled the spar using the trusty (and calibrate-able) iPhone app from Stanley.

I couldn't decide whether negative or positive 0.0 was better, so I left it with negative. My wing stand mechanism sure made this easy. Every 1/4 turn of my adjustment nuts was about 0.1° change. Easy to dial in.

Then, I needed to address the spar bowing in the middle from the weight of all the components. (Once the skins are on the wings, they provide that support, but until they are, there is no (what I’ll call) lateral rigidity.

A variation on a (wing stand) theme. a threaded rod between two 2"x4" blocks.

I thought about this a long time ago, and I didn't know if it would work. It worked great. I know it's not permanent right now, but still, very elegant setup, if I do say so myself.

Oh yeah, I snagged this picture to elaborate on the reason for the larger angle off the outboard rib from the other day. See how the skin overlaps the edge of the rib and spar? I won’t have to notch my support angle to accommodate the skin now.

With the larger angle, there is plenty of room for the skin overhangs.

Okay, time to remove the spar sag.

I tied a piece of string between the top edge of two clecos (actually, it didn’t need a knot…the cleco clamped the string enough).

It's about 1-hole-diameter distance above the hole.

Same on the other side.

Before removing the sag, you can see how much bow there is (look at the row of primed countersinks).

There's about a 1/2-3/4" of bow in the middle of the spar.

A few cranks of my adjustable homemade jack, and the middle of the spar shows the same distance with the string. This was equally as easy to dial in.

Nice and level. (Ooh, that "flush" rivet on that nutplate isn't so flush. I might need a rivet shaver...)

Then, with everything level, I clecoed the leading edge skins to the spar.

Leading edge skins now clecoed to the spar.

Now I can move on to the inboard leading edge rib. It comes undrilled, so first thing, I kind of held it in place and made little marks where the holes were going to go.

You can see my very faint marks.

Then, back to the workbench for fluting (between the hole locations) and flange bending (to 90°).

I had to pretty aggressively flute in some places. Some of these ribs are better than others.

Okay now I need the…what is it?

W-423 Joint Plate.

Okay where is it. I’m sure there are two of them, one for each wing…

[searching shop storage …hmmm…and the airplane room upstairs…hmm…]

Grrr. Where did they go?

Upon closer inspection of the plans…


That was easy.

I marked my half inch line and then pondered how I was going to fit this round (straight) peg into the square (rounded) hole.

This goes in there.

[Many loud, frustrated grunting noises…]

Ahh, there we go.

Then, after careful measuring, checking, drilling, remeasuring, and rechecking, I had the right joint plate and inboard rib drilled.

That was annoying. There was no good way to clamp everything, so everytime I drilled a hole, the rib shifted on the other side.

This one turned out pretty good. 11/16″ all around. I repeated that exercise on the left wing.

I don't have the perscribed 11/16" flange that I am supposed to on the left wing for the tank nutplates because everything moved around a little.

It’s only 1/16″ short in some places. I’m assuming I can make it work with 10/16″, but if I can’t, I’ll just redrill a new joint plate.

Anyway, I was staring at the opening for the stall warning vane, so I got curious and fished out the (separately packed…not really part of the original wing kit) stall warning components. They have this doubler that fits in this hole, with a couple locator tabs (in case you are modifying an existing leading edge that was not prepunched with this access hole). Since mine already has the hole, I snipped off the tabs.

These directions are crazy complicated, but they ended up being mainly for retrofit into an existing wing. For new construction, it's pretty straightforward.

I definitely need the access plate doubler and cover no matter what, but I did give some thought to whether I am going to install the stall warning vane.

I am planning on using the Dynon AOA vane, which will give me good stall warning (I believe it is calibrated during some demonstrated stalls for the highest AOA seen during stall for any flap configuration). For awhile, I kept thinking that I won’t need the Van’s vane (and I was a little miffed that they cut a big hole in my leading edge!), but then the CFI in me woke up and thought of a few things.

Every once in awhile during a rotation or flare, I might get a little chirp of the stall warning. Everyone does, and it can’t hurt to have a small reminder, separate and therefore redundant from the Dynon Air Data Computers (ADCs…wait, I think dynon calls them ADAHRS…or air data, attitude and heading reference system) during slow speed maneuvering. The Dynon is based on pressure differential (between the front and the angled top of the pitot probe), and the other is based on direction of relative wind (the vane just lifts up and compresses a microswitch when the relative wind pushes up on it).

I’m going to go ahead and install all of the provisions for both. It will be pretty easy to get everything installed, and just leave the little vane out if I don’t want it in the end, but I have to fill all the rivet holes anyway, might as well not rule out any future decision changes.

I’ll probably install both; you can’t be too aware of low speeds, and frankly, it will probably help resale to have the more traditional stall warning.

Anyway, I drilled the doubler plate to the leading edge.

Then, I found the leading edge vane support rib. They come as a pair of two; one for the RV-9, and one for the RV-7,8. It was obviously while holding it up to one of the leading edge ribs that the one with the sticker on it is the correct one.

So I wouldn’t forget, I tossed the other one in my scrap pile.

The one on the right is the one for the RV-7 (and -8).

Whew. Good day. I’ve made good progress in the last few days. Tomorrow, back to work, but hopefully I can keep this up.

Oh, and for the record, I hardly had enough 3/32″ (silver) clecos to do both leading edges at the same time. I just ordered 100 more, but I am going to need way more that that to keep working on both wings at the same time. This might be a good time to work on one wing at a time…or break down and order the 500 or so that Vans suggests.

3.5 hours.

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