edge finishing | Andrew's RV-7 Build Log

I Hate Drilling Stiffeners

August 15, 2011

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.)

Prev | Next

2 Comments | Wings | Tagged: ailerons, Drilling, edge finishing, Hate, skin, Stiffeners | Permalink
Posted by Andrew

I Hate Making Stiffeners

August 14, 2011

Prev | Next

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.

Prev | Next

Leave a Comment » | Wings | Tagged: Drilling, edge finishing, scuffing, Stiffener, Stiffeners | Permalink
Posted by Andrew

Prepped and Primed First Wing Rib

January 6, 2011

Prev | Next

Well, since my tool order from Cleveland finally showed up, I decided it was time to jump into rib prep full speed ahead. Because I have already finished most of the edges, fluted and bent the flanges to 90°, I really just needed to prep the lightening holes (which I couldn’t get to with the 6″ scotchbrite wheel) and use some emery cloth to get the smaller crevices.

Here’s the tool order. Along with 75 1/8″ clecos, I got 100 more 3/32″ clecos, a 2″ scothbrite wheel, the mandrel for that wheel, and some #41 and #19 drill bits.

I love new, shiny clecos.

I put a washer on the top of the mandrel and then screwed down the wheel.

Crap, not enough threads.

Took it apart, removed the upper washer, then assembled it again.

I'm showing one thread, but that's okay.

In order to start taking apart the wing to get at the ribs for prepping and priming, I needed to unjack the rear spar, which means I have to remove the leading edges, which are clecoed to the main spar before allowing the weight of the wing to bend everything.

Here are the leading edges on the workbench.

I guess I snapped a picture of my 320 grit emery cloth. (This isn’t really cloth, it’s more of belt-sanding sandpaper. It works, though.)

320 grit from NAPA.

I chucked the 2″ wheel in the drill press and started cutting grooves in it (with the ribs I was deburring).

That groove is from one rib's lightening holes. I'm going to need more scotchbrite wheels.

After completely edge-finishing the rib, including flossing the little crevices with the emory cloth, I dimpled the one hole in the rib that is underneath the rear spar flange, which also needs to be dimpled to accept a dimple in the skin. Here’s the right rear spar, lower flange hole that I dimpled.

Dimple!

Then, I primed the rib.

Still wet from primer...

The next morning, it was dry, and I snapped another picture.

Nice...

This took me about an hour, but I spent a good 20 minutes getting organized first. I won’t prime each rib individually, but I’ll probably do them in groups of 5 or so to break up the monotany. Tthere are 28 total main ribs…I’m not even going to think about the leading edge and tank ribs yet).

That one rib looks good, though. I need to think about ordering some snap-bushings for the holes in the forward edge.

Prev | Next

Leave a Comment » | Wings | Tagged: Deburring, dimple, edge finishing, prep, Priming, Rib | Permalink
Posted by Andrew

Primed and Started Riveting Right Rear Spar

September 12, 2010

Prev | Next

Well, after a $15 stop at Napa ($10 for primer, $5 for sensor-safe RTV), I got back to work on the rear spar.

I spent a lot of time just kind of staring at everything today. The instructions are careful to point out that at the inboard part of the spar (where the reinforcement fork is), you can’t reach the spar flange holes with dimple dies for later dimpling, so you should do it now.

With that in mind, I wanted to make sure I got everywhere that may need dimpling later, so I also dimpled above the two (middle and outboard) doublers. You can see in this picture (the middle doubler) where I decided it would be a good idea to dimple (drill, deburr, then dimple, of course) the flange holes. I did this for both the spar and the doubler plates, which also have flanges on them.

The middle spar area, shown after drilling, deburring, and dimpling the flange area.

Same thing here. Also, I dimpled the 4 outboard holes (instead of countersinking), per previously approved builders who have talked to Van's.

I got back to thinking about the tank dimple dies, and whether they were really helping with skin-to-structure attachments. The idea is the the tank dies (which are deeper to account for pro-seal while riveting the tanks), when used on the skeleton, allow the regular dimple in the skin to sit better once riveted.

I got out some scrap, dimpled the “skin” with regular dies, and dimpled the “skeleton” with one tank and one regular die.

You can see on the left, those are the regular dies. The ones on the right is a regular die sitting in a deeper tank dimple. The tank dimples didn’t help anything sit better, because they were both fine.

A little blurry, but the "skin" sat equally well for both set of dimples.

The tank (deeper) dimple is on the right. You can see I'm not having any "seating" issues on the left.

Anyway, I think I am going to go back to using the regular dies on everything. Enough about that, though, let’s prime!

The rear spar components, getting primed after some more edge finishing, washing, drying, and positioning in my wood floors boxes.

Also, I went back and masked off the spar where I had countersunk.

Some of the nutplate attach rivets are not as flush as I would like them to be. I may get a rivet shaver and shave some of these down and reprime. We'll see how the tank skin sits on them.

Back on the rear spar, I posted a couple pictures of my edge finishing procedure. First, use the Permagrit block to smooth out the tooling marks. This picture is the resulting burrs that need to be deburred.

The permagrit is great, but it does leave some pretty decent sharp edges.

Then I used my “v” deburring tool to knock off the 45°.

After this, I usually use a scotchbrite pad to smooth everything out.

After blowing the aluminum dust off with shop air and a good wipe-down with MEK, I took the spar outside so I could paint the grass with my overspray.

I think this is the second side. Only one bug landed on my spar. I left him there for now. (He may be my first passenger.)

After a few hours, I returned out to the garage (workshop/mancave) to do some riveting.

First step: Ignore Van’s suggestions to tape off all of the holes that don’t get riveted now. (I know the warning bells must be going off right now, but it all worked out fine. Just have to read the plans carefully.

I left clecos in all of the “do not rivet now” holes. 6 regular AN470AD4-4 rivets on the left, and some AN426AD4-4 (I think) rivets in the dimples on the right.

SEP 14 UPDATE: WHOA! Those 4 on the right can’t be set now, because the W-712 outboard rib will get riveted to these holes, too. Glad I didn’t get to happy with the rivet squeezer.

These 10 can be riveted now. (Sep 14, 2010 Update: Nope. Just the 6 on the left can be set now.)

Same exercise here. Only 5 rivets can be set now.

I didn't really mark anything here, because I didn't really start on riveting the fork on yet. Next post, I'll be very careful about what to rivet.

Then, I actually started riveting. I love my new Cleveland Main Squeeze. Squeezing these An470AD4- rivets is so easy now.

Here are the 5 shop heads from the middle of the rear spar.

The same 5 from the manufactured side.

Oh, and I did 6 more at the W-707F doubler plate, but forgot to take pictures. 11 total. Also, I was mixing this and house projects over the course of a few hours, so I’m going to estimate it was about 2.0 hours today.

Prev | Next

Leave a Comment » | Wings | Tagged: Deburring, dimple dies, Dimpling, Drilling, edge finishing, flange, Permagrit, primer, Rear spar, reinforcement fork, rivets, RTV, scotchbrite pad, tank dies | Permalink
Posted by Andrew

Trim Tab Fitting

July 1, 2010

Prev | Next

Okay. Today was a pretty productive day. I had taken everything apart, then realized I still had some more fitting to do on the tab, so I put it all back together again. Before that, though, I thought and thought about what to do about the two holes on the right side of the picture. These are for the fiberglass tips, and they are supposed to be matchdrilled later, after the counterbalance skin is installed as a lap joint underneath. How can I deburr parts that are riveted together if I drill through both? Maybe it’s not a big deal, but I decided to drill them to #30 now (for #6 screws).

Two holes the right before drilling...

...and after.

Then, I was thinking ahead about the safety wire trick you have to do with the hinge pin. Why not drill that now, so I can deburr before priming?

I drilled this just larger than 0.060, which is one of the biggest safety wire sizes.

Next, time to deburr and dimple the left elevator spar.

Me dimpling.

And after everything was dimpled, a nice picture down the spar of my blurry recycling bin, golf clubs, and motorcycle jack. (No motorcycle anymore, but the jack comes in handy to lift the corner of a car when a tire needs to be taken off for one reason or another.)

Spar! (I'm tired, so we are down to one word captions for the day.)

Another shot of the same.

Dimple! (Wouldn't it be annoying if I everything I wrote ended in an exclamation mark?!)

After edge finishing the two hinge reinforcement plates, I shot them with primer.

Primed!

Then, my attention turned back to the tab. I’ve clecoed the elevator half of the tab hinge back in, and on the right you can see my drilled riblet!

Drilled riblet! (Okay, I've had enough of the exclamation points.....!)

Here’s a better picture. I basically drew a line perpendicular to the hinge line up from one of the holes along the trim spar, then spaced them at 1.5 and 3 inches. That spaced everything evenly, and gave me plenty of edge distance all around.

Don't look at my edges, they aren't finished yet, but you get the idea.

Then, I stuck the tab on and inserted the hinge.

As some would say, "Easy Peasy."

Other direction, just for kicks (not as much deflection due to cleco interference, but again, you get the idea).

Because I bought a longer section of hinge to replace my bad first attempt, my hinge pin was long enough to actually fit (Van’s says they will send you the real one (because it needs to be longer than 18″) in the finish kit.

I got to bending.

After more bending, I ended up with something like this.

Ooh, isn't that pretty! The safety wire hole I drilled earlier is in the middle there, and will allow me to safety wire this hinge pin to the spar so it won't COME OUT IN FLIGHT!

Then, I figured out how to do video. They speak for themselves, but keep in mind that while my gap is intentionally small, I still need to edge finish, which will open them up.

Another video, this time a little closer. You can see I am pushing and pulling left and right to make sure there is no interference even with the small amount of play in the hinge. I think I am okay, but this will probably open up a little after edge-finishing.

Two hours of late-night-hinge-pin-bending bliss.

Prev | Next

Leave a Comment » | Empennage | Tagged: #30, clecoed, counterbalance skin, Deburr, dimple, edge finishing, fiberglass tips, hinge reinforcement plates, left elevator spar, matchdrilled, riveted, safety-wire, tab | Permalink
Posted by Andrew

Left Elevator Riblet, Day 2

June 29, 2010

Prev | Next

Captain’s Log: Day 2. Great success with the riblet.

So after yesterday’s wasted (I know, it wasn’t really wasted) time making two FAILURES of riblets for the elevator trim cutout, today’s worked out much better.

I had actually woken up at 3am in a cold sweat; “Oh my gosh, I need to tie the front of the riblet into the elevator trim spar.” (Warning: Cold sweat may be exaggerated.)

Anyway, I got out the jigsaw with a fine metal-cutting blade and found that this technique was far superior to the snips, which leave little ridges along the cut.

So, more measuring, tracing, and drilling/cutting.

This is try #3.

Then, after judiciously edge finishing (which is a must before bending aluminum…ask me how I know.)

Okay, Those bends are pretty good, let's work on the front.

Hey pups! (I took about 15 pictures of them for your viewing pleasure, but this is the only one that wasn't too blurry.) Jack and Ginger, curious about the airplane.

Also, I had picked this surface conditioning kit up at Harbor Freight. 1-inch diameter, and blue is finer (I think) than maroon.

This worked pretty well for quick finishing. I want to try the larger sizes, too.

You can see from the paper template on the right that wasn’t going to tie in to the spar. I cut out the corners on the piece to the left pretty roughly.

Old template on the right, current work piece on the left.

So then I edge-finished and bent the three tabs that tie in to the spar. Because there was a dimple already in the bottom flange of the spar, I went ahead and drilled and dimpled that one ear on my new riblet.

How do you like the nice sharp picture of my set of needle files and permagrit block? (And very blurry pic of my riblet being dimpled. The yoke and die just barely fit.)

Here’s the almost finished product.

It's kind of cute.

So it doesn’t fit “perfectly” in the openeing, but this is close enough that I don’t need to remake it. I’ll tweak it a little and reduce some of those gaps you see in the coming days.

Pretty darn good.

The big gap on the left is actually the elevator skin bowing locally that I need to fix. The riblet is actually straight.

I'm so happy this one worked out.

Maybe later this week or this weekend, I’ll get this tweaked and drilled/dimpled. Then, I can move ahead with prepping the elevator for prime and riveting.

An hour of wuhoo!

Prev | Next

Leave a Comment » | Empennage | Tagged: dimple, edge finishing, elevator trim, Ginger, Harbor Freight, Jack, jigsaw, Permagrit, riblet, trim spar | Permalink
Posted by Andrew

Right Elevator Stiffeners and Priming

April 12, 2010

Prev | Next

Today was pretty boring. All I did was trim the aft end of right elevator’s stiffeners and prime the two spar reinforcement plates.

Here's half of my right elevator stiffeners.

Of course, I finished deburring, edge finishing, and cleaning the two right elevator spar reinforcements. I even got the girlfriend involved. She took the parts inside and scrubbed them down with dawn. Now it really is “our” airplane.