Slow going

The weather has been fantastic for a fairly long stretch of days now and that's caused progress on the plane to slow to a crawl. The weekend was filled with flying and other outdoor activities, but I've still managed to get out to the hangar for some RV-12 buildin' now and then.

On Sunday morning I flew down south to visit The Jackson Two. Jackson is not too very far from Portsmouth so we combined the trip with a nice breakfast at the airport diner. While we were visiting the shop and comparing notes, we came across a few open holes in their fuselage that looked as if they really ought to have rivets in them by now. We tracked down that problem, but I returned to Schmetterling with a renewed resolve to make sure I hadn't missed anything before installing the side skins. I found two things that needed fixing.

The first thing wasn't actually an oversight or a mistake on my part. While I was perusing the internet looking at other builders' blogs to make sure there weren't any "before you put on the skins" hints I may have missed, I came across one that suggested testing the fit of the upper firewall section with the longerons. I'm glad I did!

Both of the longerons were just slightly too long and kept the upper firewall from matching the rivet holes in the skins.

The longerons had to come off for deburring anyway so it turned out to be very easy to fix. The second thing was something I had missed. It was those cursed plastic blocks again. I had missed a sentence instructing me to open the holes to 5/16". I think the reason for doing that is to allow them to sit flush against the belly skin rather than up on top of the nuts that hold the screws in. The reason for wanting the blocks down a little lower probably has to do with keeping the fuel and brake lines down out of the way of the flaperon mixer.

That was not so easy to fix. They  were very hard to get out of there. Putting them back was a little easier because the holes were much larger. It would have been a lot harder if the side skins had been riveted on, though.

With the skins and longerons off, I decided to get started on painting the interior. I seemed that it would be a lot easier to mask the areas that I don't want painted without the skins on, and the skins themselves would be easier to paint if they were sitting out in the open.

I picked a beige color of textured Rust-Oleum rattle-can paint for my interior. The texture is nice because it feels robust, and not inconsequentially also hides any dust or small flying insects that may get caught in the wet paint. Commonly available rattle-can paint is nice because, well, it's commonly available. Of course, with my luck the color that I picked will soon be discontinued and only available as a collectors item on eBay. Buy It Now for $65 a can!

Painting the interior is like a microcosm of the entire build. Hours and hours of preparation followed by a few minutes of riveting, or in this case, painting.

I would have gotten the floor sections done tonight but I ran out of paint. I bought three cans, but one of them was a dud. It apparently leaked out all of the pressurized gas that forces the paint out of the can, so it's useless. That means a return trip to Walmart where I already know what I will find: a big empty space on the shelf where Rust-Oleum MultiColor Textured paint in Caribbean Sand used to be.

Wikipedia, wrong again

Wikipedia continues to disappoint. The most recent example of an incorrect entry is on the topic of "what is the densest element?"  Here's their answer:

"The measured density of [iridium] is only slightly lower than that of osmium, which is often listed as the most dense element known. However, calculations of density from the space lattice may produce more reliable data for these elements than actual measurements and give a density of 22650 kg/m³ for iridium versus 22610 kg/m³ for osmium. Definitive selection between the two is therefore not possible at this time."

"So," you ask, "how can you so definitively say that such a non-definitive answer is wrong?"

Simple. Because the correct answer is neither of those. The correct answer is.... well, I'll get to that.

First, I had to cut the second spar slot in the right side skin.

As you may infer from the fact that I'm wearing a sweatshirt, our heat wave has been replaced with unseasonably cold weather. Ohio weather is at best a study of extremes, best studied from more temperate states.

I used the nibbler again, and while I think it makes a cleaner cut than shears, it does present the down side of being somewhat difficult to hold on a completely straight cut. You won't have any trouble choosing the side that I cut versus the side that Van's cut.

I was wrong when I said that it was a waste of time to cleco the left skin onto the fuse. It turns out that the little gusset that needs to be riveted on is accessible even with the skin in place.

 My prediction regarding impending match drilling was proved correct pretty quickly. I thought this picture in the build manual was odd, though. That hatched part in the circle gets cut off once the longerons are drilled. I didn't think it was odd to have a piece on there that would later get removed; every now and then there is a tab that must be used to hold the part in whatever machine Van's uses to manufacture parts. I just thought it was odd that they had bothered to drill holes in it.

I can live with "odd" in the short term - I just move on with the stuff that isn't odd.

The skin gets clamped to the longeron. That's not odd at all.

Then drilled.

Each hole is clecoed as soon as it's drilled to hold the skin flat.

I didn't see any reason to drill for a part that's going to get cut off anyway.

Then, the next side. As I was drilling my way down the side, I noticed something wrong on the roll bar support plate:

The hole was marked for countersinking, but no countersinking had been done! I figured I'd finish drilling the longeron row and then fix the countersinking mistake. I eventually got to the end, where yet again I was confronted with the inexplicably over-engineered throw-away part. I mean really, why have us drill holes through a part that's just going to get cut off and thrown away? Then it struck me, and I have to confess that the simplicity of the answer embarrassed me: to put holes in the longeron for the tail cone to rivet into. The part of the skin that gets discarded acts as a drilling template.

So now you can see why I believe that neither iridium nor osmium is the densest element on Earth.

It's because I am.

Once all of the longeron holes were drilled, I went back to countersink the hole on the roll bar support.

For some reason I couldn't get the countersink bit to dig deep enough into the hole. After a couple of adjustments to the bit cage didn't help, I thought that maybe something was obstructing the part of the bit that goes through the hole. Well, I was right, in a way.

I hadn't match drilled those holes yet.

See? Iridium ain't got nothing on me when it comes to dense.

Inspiration

It's easy to get bogged down in the nitty-gritty of installing nutplates or riveting pieces-parts to parts-pieces and lose sight of the bigger picture. Here's a reminder of the end game:

Photos by Tony Tessitore

Side Splitting Fun!

After a few days of avoiding the late-August heat and humidity, it was a relief to have a day in the mid-70s. It's been pretty hot out in the hangar so I've been spending my time on low-stress jobs like priming the longerons and trying to figure out how to install the Dynon D-6 in the flying airplane. I've finally developed a plan and ordered the parts to plumb the unit into the existing pitot/static and electrical systems, but I'm still flummoxed on the question as to where to mount the external compass module. Just figuring out which pieces of pitot/static plumbing supplies I needed and how to find them on the vast AircraftSpruce.com website took the better part of two days. Well, not "days" in the traditional 24 hour sense, or even the 8 - 10 hour work day sense. I mean two days in the I-get-about-an-hour-a-day-to-spend-on-stuff-like-this days.

All that's done now, except for the waiting for the FedEx Ground truck to deliver my stuff. That's not until next week, so I braved the temperate temperatures and high winds this afternoon to go out to the hangar and cut the spar slots in the fuselage side skins. The directions suggest the use of tin snips for the cuts, but I've always found snips to be somewhat abusive to the edges of the cuts. Or I'm just using them wrong. Which of those is the actual cause is moot, of course, since 'tis yours truly what has to make the cuts, right? Right!  I thought I'd try out my Harbor Freight nibbler instead. Clever as I am, I also thought I'd try it out on a piece of scrap metal first. My opinion after said test is that the nibbler makes a straighter, cleaner cut, although I did discover that it likes to scuff up the surface of the edge. I figured a layer of protective masking tape would solve that issue, though.

Step one: remove the pesky blue plastic.

Step two: clamp down the skins. The wind was 14 gusting 20, and the 20 knot gusts were threatening to blow the skins right off of the workbench.

Step three: make very sure that I'm cutting away on the correct side of the slot. My experience with the incorrectly bent longeron and my even more traumatic experience as a spectacularly failed orthopedic amputation surgeon encouraged me to be extremely diligent in marking the correct part of the skin to be removed. Much like cutting off the wrong leg, there's no fixing a mistake here!

Step four: see if I can find a perfectly sized rectangular drill bit to remove the metal in one shot. Failing that, use a nice, fat round bit to create a hole for the nibbler to start nibbling in.

Step five: lay down a prophylactic (oh, get over it. That word has a much more generalized meaning than what you're thinking of) layer of tape.

Step six: nibble, nibble, nibble.

The nibbler is also very good at trimming the edges after the first rough cut.

And there it is!

It was a waste of time since it will have to come back off, but I couldn't resist tacking the side skin on to see how it looked.

As I was looking through the top row of holes in the skin and seeing but raw longeron through them, I figured one didn't need to possess the prognosticative powers of the perspicaciously prescient Nostradamus to see what's coming soon: a whole lotta match drilling.

Oh goody.

Biting the bullet

I had put it off for as long as I could. I have looked at them from every possible angle, agonized over whether or not I had them bent just right in all three dimensions, found other things I could do to further postpone the decision to commit to drilling them, and finally reached a conclusion: it was time to bite the bullet and match drill the longerons. There was nothing to be gained by putting it off any longer.

An excuse I had been using was that I didn't have a suitable piece of scrap to use as a stunt double for the side skins, but I found just such a piece while searching the shop for something unrelated. I also found the missing fuel nipple that gave me such grief. Typically, I did not find what I was actually looking for.

The first step was to get the scrap faux-skin clamped to the longeron.

Then the canopy sill was clamped on such that its edge was overhanging the faux-skin.

In order to have any kind of stability at all for the impending and ultra-critical drilling operation, I had to find a way to hold the assembly in place on the workbench. I clamped it to some of the left over 2x4 scraps from the construction of the workbench.

With the traumatic memories of the 71 hole drilling marathon of the center section still painfully fresh, I dreaded drilling through the longeron material. I needn't have worried. I loaded one of the brand new #30 drill bits that I had purchased from a tent-dwelling huckster when I was at Oshkosh. Truthfully, I didn't see how these bits could come anywhere near the lofty promises that guy was making, but I have to admit that I was wrong to doubt him. Hot knife, meet butter. Those bits tore into that aluminum like a Doberman into a pound of bacon.

Even though the longerons will have to come back off for deburring and priming, I went ahead and clecoed them onto the fuselage just to make sure everything fit.

Once they're cleaned up and primed, I'll be just about ready to rivet on the side skins. Before I do that, though, I'm going to do a thorough audit of any holes that don't yet have rivets in them to make sure that I haven't missed the step that would have filled them. Things are going to start getting a little harder to reach once those side skins go on. 

The Cure

It was a much better day at the paying job today. I was able to mostly avoid the business-side professional naysayers, critics, and obstructionists that made yesterday such an ordeal by crouching deep down and hiding in the technical trenches. In other words, I stayed busy developing software and successfully avoided meetings and random interactions with co-workers. Don't get me wrong - I love the people that I work with. It's just in the nature of the job that every time I emerge from my den to head to the coffee area or restroom, I run the same risks (metaphorically, of course) as a gazelle trying to get to the watering hole. Where the gazelle has to be wary of lions, tigers, and bears, I have to be ever vigilant of the co-worker approaching me with a "Hey, would it be hard to..." or "I know you're busy, but..."  Those are invariably indications that I'm going to be pulled into a distraction that I could do without, given my druthers.

Again, don't get me wrong - those kinds of things are the reason I'm there and I'm always ready to lend a hand, but the loss of mental momentum that comes with distractions can end up costing me hours. And every now and then I have to work with someone from outside the organization that doesn't understand our business or why we do the things we do. It's an easy matter for them to throw bureaucratic roadblocks in our way without fully understanding the costs of doing so. That can be frustrating.

That happened yesterday.

Those rare days when I can spend the majority of my day head-down writing code are typically the most rewarding, if not always the least frustrating. Building software applications is a lot like building an airplane. There are moments of hair pulling frustration, there are hours of routine grunt work, and there are bright, shining moments when I suffer one of the Brief Moments of Lucidity(tm) upon which I have built a moderately successful career. Those come at a cost, though. While I'm in one of those spells I tend to write a dozen or so very elegant lines of code that miraculously perform the same function that would normally take hundreds of lines to do.

That's all well and good for the few fleeting moments when I can see the inner workings of the magic with laser-sharp comprehension, but there inevitably comes a day when I have to re-visit that code. Without the magic coursing through my synaptic paths, I sit there staring at it slack-jawed, evidencing the same level of understanding as a shrimp looking at a nuclear submarine.

The fun part about what I do is that every little thing is a puzzle to be solved. The frustrating thing about what I do is that every little thing is a puzzle to be solved. Whether each puzzle is fun or frustrating depends on a number of things, but what doesn't change is that each offers dozens of possible solutions, each having its own set of pros and cons. The beauty of the autonomous nature of my work when it doesn't involve the business-side folks is that I can pick the solution that best fits my mood. I can develop an elegant, artistic solution, or I can choose a brute force approach that throws a little more work to the end users. Today's case was one of those. I could spend hours figuring out how to restructure and import old legacy data into a new database model, or I could just build a screen that would let the end users import the old data a piece at a time as needed, applying the restructuring as they went.

I chose the second option.

It was already mid-evening by the time I got to the hangar to do a little work on the plane, but the weather was perfect for being out there. Just the right temperature, a pretty sky, and a light breeze. Truth be told, I probably should have gone flying. I chose to jump in with some easy RV-12 work instead. The first job on the page was to separate a couple of parts and rivet them to other parts. These little parts had given me some trouble when I was gathering the pieces from the store room to carry out to the remote site. The problem was simple: I couldn't find them! I finally consulted the inventory sheet and found that I couldn't find them there either. That means that they're probably in one of the bags, but I couldn't tell for sure since the bag inventory sheets stay at the hangar. There were also a couple of other larger parts that I couldn't find, but they were further down the page so I decided to worry about them later.  That turned out to be a good decision - I found them out at the hangar.

It was one of those parts that I installed early because it was much easier than it would have been now. I just failed to mark the step in the manual to remind myself. Typical POMOM*

I pulled the little parts out of the bag and riveted them to the bigger parts.

The bigger parts each get riveted to the fuselage using eight of the non-standard LP3-5 rivets.

Oh, remember the mystery holes from yesterday that looked like they should get a rivet installed but the plans didn't say to? Those turned out to be for use with the optional lighting kit. I'm not 100% decided on whether or not I'm going to install the lights, but I'm going to leave the holes open just in case. I mention it now because I no sooner solved that mystery than I found a new one. The posts that get installed with eight rivets have (wait for it....) ten holes.

Those supports will, amongst other things, support the arm rests. Van's left a little busy work on the arm rests; a small area of metal has to be cut out. Just to twist the knife a little, the arm rests are too long to let the band saw get a clean line on the areas that need to be cut out, so some clean up with a small file is required.

As I was deburring the arm rests, I noticed that one of the flanges on the end of each seemed to have been damaged in shipping. It turns out that one should resist the impulse to straighten them out.

Van's, in their typical inimitable style of doing nice things for us right after sticking us with a piece of busy work they could have done for us at the factory, put that bend there so that the part would fit better once installed.

* Problem Of My Own Making

Workborne pathogens

Much as with their airborne counterparts, workborne pathogens have a way of infecting low-immunity persons such as myself, often leading to unshakable feelings of malaise, angst, frustration, and outright anger. Two out of four today for me. The latter two, if you must know. Having spent the better part of the day struggling to finish a two day project (today was the sixth day), I was in the mood for working on something more productive and tangible than the computer bits and bytes that I push around all day hoping to form into useful tools,

Lucky for me, I have just the thing for that.

Tonight marked the return to "normal" work. I knew that the tide of struggling with unsatisfying longeron bending had receded when I was directed to countersink some holes in preparation for (you guessed it) nutplates. I'm actually skipping ahead a little bit, which is a polite way of saying that I'm avoiding some work I don't want to do on (what? You guessed it again!) the longerons. Namely, match drilling the holes from the canopy sills into the longerons. I'm putting it off because it requires a .025" thick piece of scrap aluminum. The designers and manual writers at Van's have yet to internalize the fact that the RV-12 generates very little scrap metal (although it did manage to generate quite a bit of scrap fuel line, at least in my case). I'll be cutting some .025 areas out of the side skins soon enough; I'll circle back once I do. Those scraps should be just the right size since the required scrap is to be used to simulate the thickness of the side skins. What could simulate side skin better than, well, side skin?

So, back to my night of relative normalcy. My goal was to get through page 23-03, at the end of which there would be a cross bar and two plates used to support the roll bar mounted to the fuselage. It was the support plates that needed the nutplates. They were slightly trickier than they looked. First of all, four of the holes on each plate are going to take flush blind rivets and need to be countersunk with the special 120 degree bit. The other tricky thing is that the plates get countersunk on the opposite side from that shown in the drawing. It plainly states that fact in the drawing, but if you were suffering from a workborne pathogen infection or something, well, you just might miss that notation. I didn't, but I could certainly see how I could have.

The cross bar clecos into place quite easily.

There are nine rivets in each side, and they're just slightly uncomfortable to get to.

Two things to note here: first, the quality of my photography is going to take a major hit from being out in the less than optimal lighting conditions of the remote factory floor, and two, it took me hand-pulling all nine of those rivets to remember that one huge benefit of being at the remote factory is having access to the air riveter.

Things were cooking along quite well. Too well, as it turned out. Consider this picture, in which it clearly states that there are six LP4-3 rivets to be installed in the rollbar support plate:

Now count the clecos:

Seven, unless I'm still delirious from my recent workborne pathogen infection.

The one in the middle is the one in question. I'm going to have to wade into the fetid depths of the internet to research that issue tomorrow. It was easy and painless to simply ignore it for now.  The rest of the riveting was a breeze, although it might have been better if I hadn't forgotten my reading (and riveting) glasses. One of the problems with working at the remote site is that if I forget to bring something, it's a much bigger hassle to go back and get it.

Fortunately, blind rivets can be read like Braille print.

I'll find out tomorrow if I need to pull another couple of rivets before calling page 23-03 complete. I got pretty close. Close enough, anyway.