deburred | Andrew's RV-7 Build Log

Right Tank Inboard Rib Work

June 5, 2011

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After another full weekend of housework, errands, etc., I managed to fit in some work on the right tank’s inboard rib.

First thing, I fished out some parts. Here, Vans has punched out three parts, T-407 and T-410.

Hmm...where are my snips?

I decided to pull both assemblies(?) out and get them all deburred at the same time.

Here are the two access hole doubler rings and four rib reinforcement plates after deburring.

I put two of the reinforcements and one of the rings away until needing them on the other tank.

Then, I took one of the rings, centered it over the stiffener bump on the inboard rib, and used a straightedge to find the center of the circle.

"x" marks the spot.

I know I’m not really working on the left tank right now, but I decided that since I KNOW the circle cutter is going to be a PITA, I’ll just go ahead and do the left rib, too.

I fished out the two end ribs for the left tank and marked them so I knew which is which.

L1 and L7.

Before mounting the ribs up on the drill press, I needed to find some wood backing. How’s this tank-rib-shaped piece right here?

Pepsi should pay me for the product placement.

Whoa. That sucked. It sucked so bad, I didn’t even take any pictures. Among other things, the circle cutter 1) wouldn’t stay in one diameter, 2) shook so badly I thought my workbench was going to fall over, 3) almost killed me twice.

But, I finally managed to get a decent looking hole.

Phew, I'm glad that's over.

See? Nice hole.

Oops, looks like the hole was a little big. No worries, edge distance for the rivets is just fine.

The hole in the rib is a little big...

After some more cursing, cheating death, and general unhappiness, I managed to get a better (appropriately sized) hole on the left inboard rib.

I think I'm going to throw away the fly cutter now. Stupid piece of crap.

Okay, I’m straying from the instructions a little here. Normally, they want you to take this access cover, hold it against the rib, and use the prepunched #19 holes to drill holes in the rib. Then, hold the stiffener right aligned with those holes, and drill the nutplate attach rivet holes. Clear?

Instead, I’m going to eyeball the clocking of the access cover (so the flat part doesn’t interfere with the indentation in the rib), then just use the stiffener ring for all the drilling. (I need to order a new access cover with no holes in it because I’m using flop tubes (don’t need the small hole), which means I need to move the float sender to the second bay (don’t need the large hole).)

You can see in this picture, the stiffener ring is laid in place, and it looks like the access cover is clocked correctly.

Access cover in the foreground, stiffener ring in the background.

Clamped.

Drilled.

Dimpled the rib, and countersunk the ring.

clecoed some K1000-8 nutplates in place.

Here’s where things got frustrating. Because I wasn’t paying attention, I just started riveting the nutplates in place.

Clearly I didn't countersink enough.

Another view. Yikes.

I drilled out six nutplates (didn’t enlarge any holes in the rib or stiffener), but couldn’t get the rivets out of the nutplates. They got THROWED AWAY!

Sorry, nutplates. You are going in the trash. It's not worth my time to fix you.

Okay, more countersinking, then try again. Still not deep enough? Ugh, more countersinking again, and finally, they were deep enough.

I got frustrated, so I stopped taking pictures. Sorry.

After much cursing and angry mumbling, I got all 24 rivets in for the 12 nutplates.

I had to drill out two more rivets because they were sitting a little proud. In the end though, I’m happy with the results.

These didn't need sealant because the access cover will be sealed over them.

A shop head shot.

24 rivets, 8 drilled out. (one third!? Ugh.)

2.0 glorious hours today.

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Leave a Comment » | Wings | Tagged: countersunk, cover, deburred, dimpled, Drilled, Rib, rivets, Stiffener, Tanks | Permalink
Posted by Andrew

Deburred and Scuffed Right Tank Skin

June 3, 2011

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Well, it’s Friday, and I had both a great and crappy week.

Enough small talk, let’s get building!

Since it was 1,000°F in the garage today, I brought the right tank skin inside (nice air conditioning) to do some deburring.

First, I deburred the outside of the skin, then moved to the interior. Per my usual, after deburring a few holes, I’d scuff up the line so I knew where I had been.

A few lines deburred and scuffed.

In preparation for dimpling (where the skin needs to slide on the workbench, I cleaned up a little, which included taking apart the vacuum to find out why it’s been making that weird noise.

Clean workbench!

Here's the scuffed skin, ready for dimpling.

I still needed to remove some vinyl from a few places, so I clecoed the drain flange on the wrong side and used it as a guide for the soldering iron.

This is on the inside of the skin, where this normally goes on the outside.

After soldering.

I did the same with the fill cap and flange. Clecoed them on the outside so I could get a nice round hole.

You can see where I've marked the flange for future positioning.

After devinyling with the soldering iron...

I don’t know what this picture is showing.

Another picture of the skin?

Oh, while the soldering iron was cooling down, I didn’t want to just abandon it to start a fire or anything, so I kept the fill cap flange out and decided to do some countersinking.

First, though, I found some 0.32″ and made a #40 hole, then dimpled with the deeper tank dimple dies.

A tank dimple to test countersinks.

After some countersinking…

After testing, I don't think these were deep enough.

I turned it a few clicks deeper and went back around.

Much better.

With the test dimple in place...now I'm happy.

Hmm. Soldering iron is still hot. Maybe I’ll fool around with some AN hardware since that stuff is coming up.

I fished out the AN hardware, both -4D and -6D sizes and screwed some pieces together based on the plans. -4 is four sixteenths, or for 1/4″ tubing and -6 is six sixteenths, or 3/8″ tubing.

On the RV airplanes, fuel vent lines are 1/4″ tubing (-4D hardware, in the background), and fuel feed lines are 3/8″ tubing (-6D hardware, in the foreground).

-4D and -6 D hardware.

1.5 hours. Proseal soon…

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Leave a Comment » | Wings | Tagged: AN hardware, countersink, deburred, fuel cap, fuel drain, fuel feed, fuel vent | Permalink
Posted by Andrew

Started on Right Wing Tie-down Bracket

August 26, 2010

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Wuhoo, the new squeezer showed up!

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

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

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

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

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

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

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

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

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

Here are the other three.

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

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

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

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

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

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

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

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

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

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

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

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

1 hour, 4 rivets.

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

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Leave a Comment » | Wings | Tagged: AEX stock, cleco, countersunk, deburred, matchdrill, Nutplates, Plans, rivets, Scotchbrite, spacers, spar, Squeezer, tie-down | Permalink
Posted by Andrew

Started Riveting Left Elevator Skeleton

July 5, 2010

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After the last couple work sessions priming various parts, I was getting all hot and bothered to rivet something. I thought I would tackle the spar reinforcements. I also forgot to charge the camera battery, so I’m using the new phone. Hopefully they turn out okay.

Here's the left elevator spar and reinforcement plates.

I got out a few rivets. AN470AD4-5 and -6.

Let's get riveting.

I clecoed the reinforcement plates and nutplates onto the spar, and riveted the four corners and one ear of the nutplate, then took out the clecos and riveted the rest.

The tape is a trick I have been using out of vanity. The rivets look better when they haven't been marred up by the rivet set.

After doing both plates, I put the spar back on the table.

Pretty.

And just to show you AGAIN how much I love my new tungsten bucking bar, here are the perfect shop heads.

The inboard shop heads.

The outboard shop heads.

Next up is to continue riveting on the skeleton, so I pulled E-705 out of the “recently match-drilled” pile and got it deburred, dimpled, edge-finished, and prepped for priming.

Ready to prime.

This is the other side after being shot with primer.

16 rivets set in 30 minutes of building after 30 minutes of shop cleanup (cleaned out the shopvac, etc).

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Leave a Comment » | Empennage | Tagged: clecoed, deburred, dimpled, edge finished, left elevator, Nutplates, Priming, Rivet, shop heads, skeleton, spar reinforcement plates, spar reinforcements, Tungsten | Permalink
Posted by Andrew

Primed Some Left Elevator Stiffeners

May 29, 2010

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Not too much today. I got the lower left elevator stiffeners deburred, dimpled and primed.

Here are some of the stiffeners on the priming table.

Then, I turned my attention back to the skin to start devinyling.

Left elevator, ready to be devinyled.

Here are a couple lines showing my devinlying process. These are made with a soldering gun held against a wooden straight-edge.

Oh yeah, almost forgot. I stumbled across another Harbor Freight coupon. I bought this ~$10 storage container for wing hardware.

I have two already, one for rivets, and one for Empennage hardware. I assume I'll need a third for wing hardware (I'll combine the rivets from wing and emp if need be).

Okay, back to the project. I’ve pulled off some of the vinly strips.