tank | Andrew's RV-7 Build Log

Right Float Sender, Riveted Leading Edge to Spar

July 23, 2011

Guess what? I worked on the airplane today, so the observant of you should realize that I am NOT on my way to OSH. Boo.

No use worrying about the spilled milk, though. More time for me to work on the airplane.

I need to leak test the right tank, but first, I have to finish sealing it up completely. Last post, I got everything sealed except for the float sender. Here’s the plans shot showing the sender, but it’s showing it mounted to the access plate. Mine will be the same dimensions, but entering from the rear of the tank in the second bay.

A couple 90° bends, and I'll be cooking with gas.

That was easy.

To install in the sender, you line up the plastic piece with the slot in the metal housing, and slide the float wire in.

Can't get any easier than that.

Now, let’s clean up and get this thing sealed in there.

Five #8 screws after swishing in some MEK.

After cleaning up a whole bunch, I put the rubber gasket in place with some sealant (couldn’t decide if I needed some or not), then put the float in, then more sealant around the edges, and some sealant for the screws.

Looks good to me.

I retested the sender and noticed 240 Ohms to 80 Ohms (I think I saw something lower before). That’s okay, my EFIS (Electronic Flight Information System) will calibrate the range of fuel levels based on resistance later.

Okay, that was about a half hour, and there are plenty of hours left in the day, so let’s move on. I think the next thing on the docket is to get the leading edge on the spar permanently. I have the leading edge landing light installed, and the tiendown bracket is good to go.

A changing of the plans picture…to the wing rivets and skins page.

Always fun to change plans.

After a few long minutes of getting the spar holes countersunk, I rubbed the scotchbrite pad over the length of the flange, cleaned up with MEK, then taped off to get some primer on there.

Ready for primer.

Sorry the light kind of precludes the primer from showing.

Okay, before I just start riveting the leading edge to the spar, I want to make sure everything lines up again. So, I want to put the tank on the spar, and the opposite skin from where I’m working.

Before I can get the tank on, I need to grab some nutplate for the inboard tank z-brackets.

Looks like AD3-4 and K1000-3 nutplates.

Here they are.

Done. I couldn't countersink very well along the spar bars, so I went a little light and used oops rivets on the very top and bottom (right and left here) holes.

Then I grabbed the outboard lower skin, and got it clecoed on.

Here's just the leading edge clecoed.

Then, I grabbed the tank and put screws in every 5th hole.

And a screw in every hole along the tank/leading edge joint. Everything lines up great and looks awesome.

I told you it looks awesome.

With the leading edge 50% clecoed, I decided it was finally time to show the FAA I’m really building this airplane. Sorry this awesome picture of a pre-squeezed rivet blocked the shot.

My visor says "Foxy's" on it. Anyone? Oh, and that rivet size looks appropriate, let's get to squeezing.

After 65 rivet squeezings, I had the upper leading edge skin riveted to the spar.

The leading edge looks so cool with no clecos in it.

After 65 more rivet squeezings, I had the lower leading edge skin riveted to the spar.

Oh man, I'm so excited.

GOOD DAY IN THE SHOP, high fives all around.

So….0.5 hours toward the tank. 2.5 hours toward the wings.

6 rivets for the spar nutplates, and 65 rivets each on the top and bottom of the leading edge. That makes 136.

Wuhoo!

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Leave a Comment » | Wings | Tagged: cleco, countersink, Leading edge, oops, rivets, skin, tank, Wing | Permalink
Posted by Andrew

Right Leading Edge Joint Plate Nutplates

July 13, 2011

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Wuhoo! Got my latest Van’s order. Below, you can see my two T-411 tank access plates, two tiedown rings, a tenth of a pound of AN470AD6-10 rivets, and the left inboard leading edge rib.

I love getting orders in.

First thing, I ran over and screwed in the tiedown ring.

Uh Oh.

It was way loose. Hmm. I know I did the 1/2 turn in, 1/4 turn out with the tap.

After some thought (and a trip to work), some of the guys were convinced that 1) I didn’t ruin the part, especially since I had only tapped the 1″ shown on the plans (and the rings are like 1 1/2″ long), and 2) it must be the tap quality.

They lent me a really nice tap (as opposed to the $7.99 tap and die set from Harbor Freight.)

I screwed in the nice new tap, and once I got past the first inch, I immediately felt a difference. When I turned 1/2″ in, the tap felt like it was cutting, instead of just pushing material out of the way. There was significant resistance at the end of the 1/2″ turn. Once you start the 1/4″ back out, there is some more resistance, then a “release.” I could tell immediately that the release was the cutting of little chips from the material.

It was like I heard angels. This is what tapping is supposed to feel like.

(The old one was just steady increase in resistance in, then decreasing resistance out.)

Just one more reason why I should have bought the $80 tap and die set, instead of the $8 tap and die set.

Lesson learned.

From the following picture, you should be able to tell that the thread cutters on the left are nice and sharp, and the apex of each blade comes to a point. The one on the right is not sharp, and the apex is kind of rounded.

The nice tap on the left, the crappy one on the right.

So now, I have about 1″ of loose threads, and 1/2″ of perfect threads. I am okay with at least four threads perfectly engaged, and 16 threads mostly engaged. If I’m worried about 10,000 lbs of holding power versus 5,000 lbs of holding power, I have more to worry about than my tiedowns pulling out.

Let’s build on.

Here's the tiedown installed.

It was subsequently removed, and will be stored in my storage box until, I don’t know, a few years from now.

Next up, I needed a nice little project.

How does the leading edge joint plate nutplates sound. Good?

Good. I’ll work on those. A quick check on the plans showed some hardware needs.

Some #8 screws and nutplates.

First, let’s cleco some nutplates to the previously dimpled holes. This worked great, and perfectly centered the dimpled nutplates over the dimples.

#30 clecoes worked great.

I drilled one ear of each nutplate, then clecoed.

After drilling both ears, I deburred, then started countersinking for NAS flush rivets.

Nice.

Here’s one of the oops rivets, just holding it in place.

This will work.

Oh man, I'm making a mess.

Then, some riveting.

All done.

1 hour, including the tiedown re-tapping, and 28 rivets in the leading edge joint plate.

Not much more in the way of sealing up that right tank.

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Leave a Comment » | Wings | Tagged: Countersinking, Deburr, drill, joint plate, Leading edge, NAS, oops, Rivet, tank | Permalink
Posted by Andrew

Right Tank Plumbing

June 30, 2011

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Okay, so a little of my work this evening was actually done AT WORK today. (Don’t tell my boss.)

Since I don’t have a Parker Rolo-Flair (shouldn’t it be “flare”?), but we have a few at work, I asked one of my RV buddies from work to show me how he does it. So, I brought my prebent -4 tube into him, and he, well, showed me how to do it.

(I was going to buy a rolo-flair tool, but at $80, I don’t want to buy one until I really need one. I need this flare (see?) now, the one for the left tank in a month or so (more like 3 or 4), and then I won’t need one until working on the fuse and running fuel, brake, and vent lines. I don’t want an $80 tool gathering dust until then.)

Anyway, he showed me how to do it, with a little cutting oil on the flaring (see!?) cone.

Back home, this is what I ended up with.

(He also showed me how to roll the straight portion of the vent line, which I was having a heck of a time getting perfectly straight, on a countertop or flat piece of door. You roll it like a roller between your fingers and the countertop. I was inside doing it on the granite countertop while the girlfriend was making dinner. She said “Get your fuel line off my counter!”)

No, she didn’t. But it would have been funny if she did, right?

FLARE!

Next, I fed the vent line through all the snap bushings and slid the inboard rib with the -4 bulkhead fitting in place.

Looks good here.

How perfect were my measurements! Now I just have to bent the end up a little to get to the highest portion of the tank.

I copied Mike Bullock here, and used a wrench and another lever to bend it slowly upward.

Nice trick, Mike.

After repositioning the inboard rib, this sucker is at the very highest point.

Oh, I also did a little safety wiring. Then, thinking that I could unscrew the nut, and re-clock it to have a shorter, more sturdy safety wire run, I figured out that the nut only has one “entrance” for the threads, so the clocking is as shown only.

First try, which was perfectly acceptable.

Second try, after reciting the famous quote ‘perfect is the enemy of good enough.’

Alright, Andrew, stop messing with it.

0.5 hours. Time to start thinking about closing this bad boy up.

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Leave a Comment » | Wings | Tagged: fitting, safety-wire, tank, vent line | Permalink
Posted by Andrew

Two More Right Tank Ribs Sealed

June 18, 2011

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Today was a busy day! Even though I’m logging all the time today as on the fuel tanks, I did spend just a couple minutes on the leading edge.

First thing, I deburred and dimpled the inboard leading edge rib, then fit it back in place on the leading edge, this time WITH the joint plate.

Looking good.

Oh, while I was in autozone today, I grabbed a tubing bender and mini tubing cutter.

These should work.

After much reading, deliberating, gnashing of teeth, and hand wringing, I decided to bite the bullet and add a fuel return line.

Not very many fuel injection systems require it, and if I got with the ECI injection (which is supposedly very nice), they say you can just add a bulkhead fitting to the inboard bay, but I think I’m going to run a -6 line to the second bay.

As of a week ago, I had decided I was not going to add any injection system that required return lines, so we’ll see how I feel in another week.

Anyway, I was milling about the parts under my workbench when I came accross the standard rigid pickup tube that Van’s provides. Since I’m using flop tubes, this is scrap, so I held it up against the tank, and figured out it would just make it over to the second bay. Wuhoo!

I guess with the normal pickup, they crimp the end and you make saw cuts in the side of the tube as the actual pickup.

First, let’s get this thing cut in half.

Not bad. Needs deburring, though.

Then, let’s uncrimp the other side so the thing will fit into the cutter (I want a fresh cut on both ends).

Yikes.

Of course, I made a fresh cut on this end too, then deburred both sides, and promptly put the tubes away before taking any more pictures. Sorry.

On to some tank ribs.

After the usual cleaning and preparations, I buttered up rib #5 and clecoed it in place. Here are some undriven rivets with tape on the heads, ready to be set.

Ready for riveting.

I went light on the pictures today, sorry. Here’s rib #5 and #6.

I still don't like the proseal on the outside of the skins, but I'm trying not to have any leaks. I hope the razor blade trick works.

Then, I repeated the whole process for rib #3.

...and my trusty rivet gun.

A picture of the top side.

Nice, except for the very last rivet I shot, which is on the lower right corner. Ding city.

Starting from the (invisible) rib all the way to the left, I did ribs 2 and 5 today.

Still need some rivet encapsulation, but overall, a really good day. 34 rivets times 2, none drilled out.

Oh, and 3 hours. (It really only took me one hour per rib, but I was messing around with the leading edge and the fuel tube stuff.

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Leave a Comment » | Wings | Tagged: Deburr, dimple, Leading edge, proseal, Rivet, tank | Permalink
Posted by Andrew

Riveted Right Tank Stiffeners

June 8, 2011

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Well, tonight was the big night. I finally got started sealing up the right tank.

The general order is as follows:

Backrivet stiffeners
Rivet drain flange and fuel cap flange (don’t forget the vent clip!)
Cleco all ribs into tank (to maintain assembly straightness)
Starting with second-to outboardmost rib (the smallest area to work for bucking), seal and rivet each inboard rib. Assuming 7 ribs, from inboard to outboard, my order will be 6,3,5,2,4,7,1. That way, there’s always ribs on either side of the one I’m working on. This may be a waste of time, but it will make me feel better.
Oh, before the inboardmost rib, I need to make sure I get the vent line in there, with the AN fitting, before bending and flaring the tubing to fit over the AN male fitting in the inboard rib.
Install anti-hangup brackets, trap door, float sender (have to move this to 2nd bay) and flop tubes.
Close tank.
Have beer in celebration.

Oops, looks like number 8 will occur after each step (but only at the end of each night.)

Okay, let’s get to the pictures. I got out my new kitchen scale, the small and large popsicle sticks, rubber gloves (snap!), MEK, electrical tape, and paper towels out. Let’s see, what am I forgetting?

Oh YEAH, the Proseal. I guess it’s really called FlameMaster tank sealant, but I’m going to continue to call it proseal.

Also, I have 900 or so solo cups from my earlier partying days, and I thought those would be great for mixing proseal. (Caveat: when the directions tell you to swirl some rivets in MEK to remove the manufacturing oils, don’t use solo cups, the MEK burns through the white coating and the whole mixture becomes milky. Ask me how I know…at least I did a test before throwing in some rivets.)

First thing, I laid the stiffeners in place without rivets just to see where I needed to protect the rib lines with electrical tape.

Okay, let's start getting messy.

Anyway, I got some rivets soaked in MEK and then dumped them out on the paper towel.

asdf

I did a THOROUGH cleaning of both the skin and the stiffeners, then said a little prayer and got to proseal mixing.

I started with 2 oz. of white stuff and then added 0.2 oz of black stuff. (The picture reads 2.3 because I kept the popsicle stick.)

Oh, and I barely caught myself before using the white-stuff-soaked stick to scoop out some black stuff. That was close.

Anyway, I did my first batch in a solo cup, and I’ve decided to immediately switch to something wider and lower-lipped. In mixing the proseal, you basically push all the proseal up on the walls of the cup, and now you really only have an ounce or so to work with, because you’ve done a great job of sealing your cup. I feel like I wasted a whole bunch of proseal tonight having left most of it on the walls of the cup. Grrr.)

My first batch was the messiest because while stirring, all my gloved knuckles kept hitting the walls of the cup and gathering proseal.

Moving on, I grabbed a….CRAP…I don’t have anything to dab proseal into the dimples of the skin! Umm….Umm…

This cable tie will work! (It actually worked great, very similar to a toothpick that others use.)

Just to test out the process, I dabbed 4 holes of one of the outboard stiffeners, put some rivets in, spread sealant on the stiffener, laid it in place, and backriveted the heck out of it!

Looks okay, but why didn't you clean up the skin (you'll find out later).

Oh man, this stuff is MESSY. After reading a ton of build sites (Bullock’s, Oliver’s, Beaver’s), I was convinced I would make mine really neat compared to their’s.

By the end of the night, I felt like I was “arbitrarily slopped all over the place as a sort of voodoo talisman employed to ward off leak demons.” (Quote from Rick Galati.)

Anyway, I flipped the skin back over, put a dab of sealant in the rest of the dimples, taped over them all, flipped the skin back over, laid the stiffeners in place and got to backriveting.

Taped, ready to backrivet.

You can see how messy the outside of the skin is going to be.

It went well. The worst part is that by wet setting the rivets (sealant in dimple before inserting rivet), there is proseal all over the rivet on the other side. That means the proseal gets all over your rivet set, and therefore my hands as I steady the set during shooting (watch for my fingerprints later).

After getting all the rivets set, I grabbed more sealant and created fillets around each of the stiffeners.

Yikes, this is not very pretty.

Finally, I filled a little 20cc syringe I got from Target with sealant and encapsulated each rivet. This part worked REALLY well.

Tomorrow, the encapsulations look even better.

See my fingerprints?

As a final note, I followed Bill Repucci’s advice and resisted ALL TEMPTATION to wipe off the skin of the tank with MEK after backriveting. Apparently, some MEK might soak under the rivet head and work its way into a leak path. (No Leaks!). I’ll try the razor blade trick later, but just so you know, that’s why these skins don’t look as pretty as Bullock’s and Oliver’s.

Bill suggests using a razor blade to clean after a week or so.

In the end, it was about 2 hours and 78 rivets. not bad for a day’s work. It was wicked hot in the garage, and I was in desparate need of some refreshment once inside.

That'll do the trick.

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Leave a Comment » | Wings | Tagged: backriveted, proseal, Stiffeners, tank | Permalink
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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1 Comment | Empennage | Tagged: Baffle, flop tube, spar, tank, Van's | Permalink
Posted by Andrew

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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Leave a Comment » | Empennage | Tagged: Drilling, edge-straightening, fluting, tank | Permalink
Posted by Andrew

Started Prepping Right Leading Edge

March 25, 2011

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Jeesh, I can’t seem to get a minute away from our third puppy to head outside and do any work on the airplane.

Tonight, finally, during halftime (go UNC!) and just after the game (wuhoo UNC!), I managed to go outside and do a couple things.

I didn’t want to do anything major; I really just wanted to go out there and get back up to speed. I’m kind of in the middle of rib prep on the leading edge, so I disassembled a few of the leading edge ribs and worked on what I labelled R3, or the third rib from the inboard side.

After deburring (back up, looks like I forgot to matchdrill some of the holes….sigh). Okay, after drilling, deburring, edge finishing, and scuffing, I now I have two right leading edge ribs ready for primer.

R2 and R3 (my numbering) ready for primer.

After pulling out the rest of the ribs (including the two outboard-ish ribs shown below), I went ahead and drilled pilot holes for the nutplate holes that are needed for the leading edge landing light installations. I had previously marked these while they were assembled with the leading edge using the provided template.

The two outboard ribs, now with pilot holes drilled for the bracket (the two small holes just above the lightening hole).

So here’s my thought. I really hate rib prep, so I’m basically going to do one at a time, then get it installed in the leading edge. To do that, I’ll need to prep (deburr, dimple) and prime the appropriate parts of the leading edge, and prep one additional rib. Generally, you want the surrounding structure in place for whatever you are riveting. Hence the need for the “next” rib to be clecoed in place while you are riveting a particular rib. If you don’t have the next one in place (have everything perfectly aligned), then the final structure may not be aligned. Make sense? No? Oh well.

So, I put the leading edge in my cradles and got to work with deburring. I got all the exterior holes deburred, did some edge-finishing with my permagrit block and my edge deburring tool and a scotchbrite pad, then started deburring the interior before my hand got tired.

Leading edge during some prep.

Oh, and out of laziness, I screwed the right tank loosely into position instead of taking it back upstairs. I think it’s going to be awhile before I get back to working on it.

It kind of has a funny shape with no ribs in it.

It was a short night, but got me back into the mood, so I’ll call it a success.

1 hour.

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Leave a Comment » | Wings | Tagged: cradle, Deburr, dimple, edge finish, Leading edge, prep, primer, tank, Wing | Permalink
Posted by Andrew

Right Tank Work

February 26, 2011

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Oh man, I had a great day today.

I’ve been kind of slowly approaching the tanks on my project. I don’t have a lot of apprehension about tank sealant, but I want to close out a few things in other places before I venture too much further.

Nevertheless, I made some big parts (at one point I had a whole wing!), but of course, by the end of the night everything was disassembled. Having the tank assembled allowed me to do most of the prep work I needed to do.

At this point, if I want to, I could go back and finish the leading edge lights on the right leading edge and start actually putting the leading edge together permanently.

Of course, I could always go back and catch the left wing up to the right. But that would be BORING. (I’ll probably keep myself entertained with the leading edge and then go back to the left wing before setting up for tank sealing.

On to the pictures!

First thing, I bolted all of my right z-brackets to the main spar.

The girlfriend was napping, so instead of riveting the inboard nutplates to the spar, I just used some spar An365 nuts.

My best tool today was the 3/8″ power drive socket that came from a gift my girlfriend’s dad gave me.

I can’t imagine having done these by hand. 2 minutes versus 20 minutes, maybe?

I don't have a picture of the whole set, but it is a really nice Dewalt driver set.

Okay, with the z-brakets bolted to the spar, it’s now time to get the baffle in place with the tank skin.

Here's the baffle.

Then, I had an epiphany. A lot of people cleco the skin to the baffle, but then don’t really have a good way to clamp the tank assembly in place to accurately drill the inboard and outboard z-brackets. Some people try to clamp it really well, others will pad the tank assembly and try to use tie-down straps around the whole wing.

I read (and re-read) the instructions, and came across a step that simply says

Drill the spar attachment screw holes and the W-423 screw holes to final size using a #19 drill.

Well, I couldn’t find a reason not to do that now, so I grabbed my recently ordered #19 bits and got to work.

Here it is.

Then, I decided that I should just go ahead and dimple the holes. Can’t find a reason not to.

(Although now that I’m re-reading the manual, I see a statement in there that says to dimple the tank skins using a c-frame and a hammer. Oh well, I think the dimples look good.)

Here's s a dimple for a #8 screw.

And with a AN509-8R8 screw.

After that little test, I went ahead and finished the rest of the spar attach holes.

These should let me really solidify the tank in it's final position for all drilling. No messing around with tie-downs for me!

I cheated a little and didn’t assemble the middle ribs. I figured the two end ribs would be sufficient.

Things are looking big now. This is the top side.

And the bottom side.

Here’s a closeup of the #8 screws helping me align the tank.

This worked great.

There were a few places where things didn’t line up perfectly, but this difference (tank on the left, leading edge skin on the right) is less than 1/64″. I’ve way zoomed in on this next picture. I would call this basically perfect. Some careful edge finishing on the leading edge will line up these seams nicely.

I can’t even figure out how I would improve this if I wanted to, which I don’t.

Lining up pretty good. For reference, that is a 1/8" hole, and I think that step is about 1/10 of the hole. Multiplication tells me it's about 1/80." There's no way any of you will ever notice this on my plane.

Near the leading edge, the gap looks amazing. Remember, this is my macro setting on the camera. Those are all 1/8″ holes.

Great (lack of) gappage.

At the leading edge, I couldn’t figure out why I had a little step here. Again, this is really small, and I’m totally happy with it.

This small step is hardly noticeable.

So other builders will drill the inboard and outboard z-brackets (which requires removing the leading edge) then you have to remove the skin to get to the other z-bracket holes, then you have to re-install both the leading edge and the tank skin to drill the tank-to-leading-edge #19 holes.

Why not do them now? Everything is rock solid and perfectly aligned.

I first matchdrilled the #40 hole into the flange behind the prepunched holes, then I enlarged the hole to #21, then finally #19.

After that was all done, I moved on to the inboard z-bracket. Like everyone else, here’s a picture of me drilling the z-bracket holes.

I had to use the flash here because this side of the tank was in a little big of a shadow. (I bent the bit a little while drilling to make sure the hole was straight.

After drilling and adding a cleco (9 times), I had the inboard side done.

Wuhoo!

Then, I apparently took another picture of the whole wing because I was so excited.

It's so big (TWSS).

Then, I struggled for about 10 minutes trying to really gently pull the leading edge off without disrupting the tank alignment.

Turns out, the joint plate and leading edge inboard rib fit so well, the friction kept me from sliding it out.

I had to remove the inboard rib (and joint plate) from the leading edge to get it to come off.

Of course, Jack and Ginger are playing in the background.

Then, the same drilling drill (ha) on the outboard side of the tank.

One done.

Nine done.

Alright, let’s get the rest of these z-brackets drilled.

After removing the skin, I saw (bracket) metal underneath all of the baffle prepunched holes. That means I didn't reverse any of the brackets.

With my drill stop attached to my #40 bit, I drilled the 25 remaining holes.

It's nice to be at this point, I've been reading about this whole process on everyone else's build sites forever.

After pulling the ribs and baffle back off, I saw holes in all of my z-brackets.

Holes were right where they were supposed to be.

Don’t believe me? Here’s an example.

Notice how the holes are slightly off-center? This was exactly what I was expecting. See the “checkoway method” explanation on my previous post (about 1/3 the way down).

It feels good to see these holes exactly where I thought they would be.

Then, I deburred the holes I just drilled in the right z-brackets.

Z-bracket holes deburred.

That was about 3 hours worth of work. Great day, and the tank alignment was great.

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Posted by Andrew

Riveted Nutplates On Right Wing Z-Brackets

February 22, 2011

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Well, nothing too exciting, except I got to bang* on some rivets.

* By “bang” I mean “squeeze.”

After the other night, I have 7 z-brackets that are matchdrilled to the spar. Six of those seven need nutplates on them.

I grabbed a cleco, a (sacrifical) nutplate, an AN3-4A bolt, and a handful of washers (so I don’t engage the locking portion of the nutplate).

Bolt with washers goes in the hole, nutplate on top, hand tighten in a reasonably aligned orientation, and drill one of the holes for the nutplate ears through the angle.

Then, add a cleco and drill the other side.

Easy as PIE.

See? Easy!

After completing the first three sets, I snapped this picture.

3 down, many to go.

I think it was…[thinking]…6 angles, three bolts each, 2 holes for each bolt…36 holes?.

After all was said and done, the sacrifical nutplate had been thoroughly abused.

I almost threw it away, but then decided to keep him in his own little container. I can't just throw away a nutplate that has served me that well!

I deburred the holes that won’t be countersunk, and moved on to countersinking. I thought about using oops rivets, but since this material is so thick, I went ahead and countersunk for a full-depth AN426AD3-4 rivet.

Guess what I found when I picked up my countersink cage?

IT WAS ALREADY SET FOR THE PROPER DEPTH! WUHOOOOO!

(It’s the little things in life that really matter.)

Anyway, here’s one hole done.

Looks okay here...let's try a rivet.

Perfect depth.

While I was countersinking, I went ahead and did the FRONT side of the spar, too. (The nutplates go on the back of the spar, the bolts for the inboard z-brackets are fed in from the front.)

The countersink on the far left isn't perfect, I need to revisit this before riveting. The cage prevented me from getting a good angle on it.

Then, back to the z-brackets for some riveting.

First one done.

Then, onto the rest. All clecoed up, ready for rivets (in the background).

R3-R7 read to go.

Then, after setting 36 rivets, I set them all back up on the spar. No bolts yet, though. I’ll save that for tomorrow.

You can see R1 (which fell over) through R6 here. R7 is hiding behind the leading edge.

It’s late, and I need to get inside to bed.

But first, I grabbed all the tank parts for the right tank and quickly mocked them up with no clecos in my cradles. That’s the baffle leaning up against the cradles in the foreground.