Rockin' on the Rollbar

The problem with quitting a work session when confronted with an unpalatable task is, of course, that your next session is more than likely going to start with an unpalatable task. That's not an immutable eventuality since there is always the slim possibility that the task in question was only undesirable because of the contemporaneous mood of the worker and will look more favorable to a fresh and rested person, but that was not the case when I got to the hangar and had to immediately disassemble all of the parts that I put in place to ensure that the rollbar was correctly positioned for match drilling to the rollbar mounts. With the holes having been successfully drilled, it all had to come apart again for deburring and priming.

Removing the panels was easy enough, but that rollbar was every bit as hard to remove as it had been to install in the first place. At least I had the job of trying to get it back on there again just a few hours later to look forward to. With everything laid out in my hyper-clean, dustproof paint booth, I applied the first coat of primer, followed by a top coat to match the rest of the interior. The only parts that were left with just primer were the two aluminum mounts that would be enclosed by the rollbar. The primer I bought at Advance Auto Parts seemed hardly up to the task. It stuck to the metal about as well as Lindsay Lohan sticks to sobriety. I knew it was all going to scrape off of the mounts when the rollbars were pushed back onto them. I also tried priming the rollbar itself with similar results. The much maligned Rust-Oleum seemed to stick much better.

While the first coat was drying, I went flying. The weather was perfect for it and I still needed to replace the fuel used for my non-BFR flight on Wednesday night. As I've mentioned before (albeit on the flying blog), calm-ish air is wonderful for flying, but it brings with it a couple of challenges: lots of other people flying, and some confusion as to which runway to use. The frustration factor comes in when people that departed from calm wind airports don't pay attention to the fact that the wind picks up later in the day. As I was waiting to depart Madison Co. (KUYF) on runway 27 with a full load of fuel, I had to wait for a guy that entered the pattern to land in runway 9.

The winds had picked up to a good six or seven knots out of the west, but either it was more convenient for him to land on 9 or he just hadn't bothered to check the wind. Fine, but the problem was that the three other planes approaching the airport heard him declaring his intentions and in a lemming-like procession all declared their intentions to land on 9. As tempted as I was to key the mike and suggest that at least one of them consult the windsock, I held my tongue and waited it out. Well, at least until one of them declared that he was going to do touch & goes. I waited for him to land but departed on 27 after his first effort as he was turning into the downwind for another try. It sure makes you wonder how they fail to notice all those extra knots on the runway - you can't miss it with an RV.

The paint was dry enough when I got back to allow me to flip over the parts and paint the other side. Faced with another wait for drying paint, I went ahead and fashioned the seat belt shoulder mounts. It was the normal separate and deburr operation, but with the added fun of adding a radius to the corners and chamfering the edges. Chamfering is just a matter of rubbing off an edge with the Scotchbrite wheel, but I still hate it. It's the word, you see. A "chamfer" sounds too much like something your doctor might find on you (or, heaven forbid, in you) during one of those socially awkward rubber-glove inspections of those private regions where you always hope and pray that nothing untoward is ever found.

As was preordained by the gods of inconvenience, getting the rollbar back on over the mounts was harder the second time than it had been the first. I really ought to compose a list of The Immutable Truths of Life. Isaac Newton, step aside. My laws will prove more robust and enduring than even yours. And hey, you only have a list of three, you slacker!

It took quite a bit of wiggling and yanking to get all of the rivets to go in. This was definitely a case where I didn't want to have to use the drill to remind a recalcitrant hole what it means to wear the #30 on this team - these things needed to line up right where they had been drilled. No room for touch-ups on this one.

The actual riveting was, as always, the fun part.

The rest of the panels were also ready to get put back on. There was a lot of dimpling to do first since there were a dozen or so nutplates that were to be installed.

Unlike the pneumatic riveting of the rollbars, the manual squeezing of the rivets for the nutplates was no treat at all.

There was one hole that needed to be protected from accidental premature installation. There are a couple of braces that go on the right side, presumably to add support for the fuel tank. That hole is common between the vertical and horizontal brace. The horizontal brace was to be installed now, while the vertical brace comes a page or two later.

Here it is, all riveted except for the top of the brace.

This was another case where the riveting was a little less pleasant than usual, even though it involved the air riveter.

It's just about ready for the attachment of the tail cone! There are a couple of braces that will go on pretty quickly before it's completely ready. I'll save those for an easy job for the start of the next session.

A forced break

Wow, did I ever find a crappy way to hurt my back! When I got home from work Friday afternoon, I was met by the guy that had just emptied our septic tank. I'm not super keen on septic tank maintenance, and apparently my negligence had resulted in the aerator motor getting so fouled with gobs of who-knows-what that it had burned itself out. Gave its life in the interest of foamy crap, as it were. Sad, yet somehow heroic.

Being a friendly and helpful sort, Mr. Septic had informed the CFO that we could save a $100 through the simple expedient of me driving across town and buying (and installing! ICK!!) a replacement unit rather than having one delivered. Well, we all know how that went; I was nominated before I even knew about it. Wish I had gotten to him earlier - I'd have sprung for a ten spot just to keep that little tidbit of knowledge between the two of us. $110 to avoid driving clear across town in the company of a piece of equipment that has spent eight years soaking in effluvium? Bargain!! But... not to everyone, and particularly not to those that wouldn't be riding along.

Long story short (too late for that, I suppose, so let's go with "long story finished, here's the punchline"), I was lifting the old crap-encrusted (and I'm afraid I do mean that literally) motor into the car while striving to touch as little of it as possible and ended up wrenching my back. Quite painfully, too.

My back loosened up a little later and it wasn't too bad across the weekend, but as I was getting in the car Monday morning (and catching my first whiff of an interior than had been infused with Eau de Septique for the weekend), my back rebelled with a very noticeable spasm. Which was followed throughout the day with another series of the same every time I lifted anything heavier than a three syllable word, made a wisecrack, or pointed out an irony. In other words, it was nearly constant. I was able to get an afternoon appointment with my chiropractor, thankfully. That was an eye opening session - heretofore I had thought the only way he could bring a tear to my eye was to present me with my bill! Turns out restorative machinations on a truly ailing back can be quite painful as well. Besides which, after dropping $468 on a new motor whose sole function in life is to stir air into sewage, his invoice looked like a bargain.

As it turns out, the pain he put me through had nothing on the bruiser of a girl that gave me a therapeutic massage on Tuesday. I had to look it up when I got home; I had no idea that "therapeutic" was a synonym for "excruciating" and "massage" is French for "the intentional bruising of internal organs." If it had been a guy doing it, I might have mentioned something along the lines of "Hey, that really hurts!" Being as it wasn't, misplaced masculine pride precluded me from making even so much as a whimper while laying there wondering if I'd actually be able to hear my ribs snap as she dug her elbow into my back so hard that she left a trench in the mattress table on the other side.

But finally I felt well enough to get back out to the hangar today. I've had a few days to look into the problem I had with the gap between the roll bar and the brace. The word on the streets was that the roll bar might move forward once I put the top brace on. That step is two pages beyond where Van's would have had me match drill into the roll bar mounts, thus preserving the misalignment of the parts for eternity. What were they thinking?? I decided to skip ahead those two pages and see if the top brace would help with the immediate problem. It looked like it might be easiest to assemble the whole, uh, assembly and attach it all at once.

It wasn't. The side bulkheads have a slot cut into them that is supposed to fit over the longerons, but it's a very tight fit. That, and the fact that the top brace couldn't be reached while holding the rest of the assembly in place, meant that it was too much to do alone. I had to take it all apart again and start with the top brace.

I was then able to put the side bulkheads in.

And take them right back out again.  Something just didn't seem right. The baggage floors weren't reaching the side bulkheads and the bottom flanges seems somewhat off. That was all because I had clecoed the bulkheads into the wrong holes in the side skins. Fixed!

When I got everything assembled, I went back and checked the gap between the roll bad and the brace.

Eradicated!

With everything all aligned, I could finally go ahead and match drill into the mounts.

It all needs to come apart again, as usual. There are nutplates to install and all of the new holes need to be deburred. I have to prime the roll bar mounts and the roll bar itself needs its final coat of paint. Then it will all get riveted back on and it will be just about time to rivet on the tail cone!

Fall Weekend

Rainy, chilly, fall weekends are perfect for two things: football and airplane building. Unless you live here, you probably don't realize that Columbus is a college town. Not so much a college town as one in which the university itself is almost the raison d'etre for the town itself, though. No, Columbus is a college town for only a handful of days all year. Those days are known as "game days." Weddings are scheduled around game days, and I suspect that more than one funeral has been delayed by a day now and then, depending on the quality of the scheduled opponent. I can state this unequivocal fact: the timing of the game this week had a direct bearing on when I worked on the plane.

Knowing that I only had until noon if I wanted to get any work done by kickoff, I headed out to the hangar pretty early in the morning. I only had a few hours to get the roll bar disassembled, deburred, primed, and put back together again. Deburring was going along just fine. It's easy as can be when I can use the deburring tool in the electric drill.

I knew that the battery in the drill was getting low on juice on Friday night, so I had plugged the spare battery into the charger before I left for the night. Sure enough, the battery died about halfway through the job. I retrieved the newly charged battery, slapped it into the drill, and.... nothing happened. I apparently hadn't gotten the battery all the way down into the charging cradle. It too was dead. Nothing for it but to proceed by hand.

That slowed me down considerably. I only had enough time to get the deburring done and the first coat of primer painted on.

While the primer was drying, I went ahead and prepped the roll bar braces so they'd be ready on Sunday.

I also still had enough time to gather up the roll bar mounts. They're pretty solid looking milled aluminum.

They get bolted onto the fuselage. I thought it odd that bolts were used since the roll bar won't actually be removable; I figure it must be a strength issue.

They look pretty professional, don't they?

As things worked out, I would have just enough time to finish the page since the last step was a simple locate & separate operation.

It all kind of fell apart on the "locate" phase. I looked and looked, and I could not find that big part! At this point the parts shelf is looking pretty barren, so I couldn't figure out how I could not find a big part like that. I eventually realized that the parts had already been separated. That's passingly odd; Van's is a lot like a teenager in that they don't do much of anything for you unless they absolutely have to. I couldn't figure out why they would have started separating a part at the factory that they apparently had never intended to.

Maybe its because it wouldn't have fit through the band saw.

Nah, that can't be it. That's never bothered them before!

Time was up and I had to run home for the game. We all take it pretty seriously!

Back in the shop this morning, I was able to get a running start on a new page in the plans. The bulkhead parts were to be clecoed into the tail cone, and I was then to mark a centerline on the tail cone pieces behind them in order to make sure the holes I was about to drill through them were on the centerline. I had to think about that: Step 1, cleco these things in place. Step 2, draw a line on two parts that were now blocked by the parts that I had just clecoed it. No way that was going to work; I did step 2 first.

That worked a lot better. Doing it that way, the marks were visible after clecoing on the bulkheads. A quick match drilling operation later, the bulkheads were taken back off.

Rather full of myself after my intellectual win over the guy that wrote the directions, I moved right into riveting on some kind of canopy hook thingy.

I then immediately drilled the rivets back out, having noticed too late that they were supposed to be LP4-4, not LP4-3 rivets. Short lived victory, that.

Oh, lest I forget, there was also a lot of countersinking and riveting to get the roll bar parts all assembled. The countersinking was done with the special 120 degree countersink because the outer side of the roll bar assembly uses the CS4-4 flush rivets. I also had to stare at the drawing for quite awhile to make sure I was getting the right rivets in all of the other areas, and that I had correctly marked the holes that weren't to be riveted yet.

Once it's all put together, it gets installed over those nifty aluminum mounts. It's a bit of a tight fit, and it wasn't particularly easy to do alone. At one point I had one end in and was walking around the back of the fuselage to try to get the other side in when the whole thing popped out and just missed landing on my head. That would have stung!

This is only a temporary installation until the matching holes are drilled into the mounts. The plans call for having a couple of braces installed during the drilling, presumably to make sure everything is aligned correctly.

It isn't.

That gap shouldn't be there, and I have no idea how to make it go away. The mounts are extremely solid and there is no way to adjust them. It seems that I have a somewhat crooked airplane.

I'll have to poke around on the internet and see if anyone else has had this problem.

Roll me up to the bar, boys!

I started Section 24 last night. This is the section that was previously known as "The Section When I Have to Move to the Hangar," but lost that designation when I realized that there was no way I wanted to do all of that Section 23 riveting by hand. Section 24 initially held the title because it is the section in which the rollover bar/hoop gets installed. With the rollover bar/hoop on the fuselage, there would be no way to get the assembly out of the basement.

As I said, I started the building of the roll bar/hoop assembly last night. It comes in four parts: a front and a back, each comprised of a right and a left. The first step, not surprisingly, is to cleco the parts together. The left and right halves of front and back pieces are held together with a plate in the middle where the halves meet, and the front and back are then held together with two long aluminum strips. It's hard to describe, but easy to see. I started by joining the left and right halves of the front hoop.

The strip of aluminum sitting at the edge of the table is the strip that will get clecoed on the inner flange at the top of the hoop. I started by clecoing it at one of the corners of the hoop.

The arrow mark is there to ensure that I get the strip back in the same place after the inevitable disassembly that is assuredly coming in the near future.  There is a similar strip that gets clecoed inside the lower flange.

The upper strip gets slid in between a gap in the upper flange.

I was clever enough to figure that out on my own; the drawing of this in the manual leaves a loy to be desired when it comes to clarity of detail. What I wasn't clever enough to figure out was that the clecos would have to go in from the other side of the front hoop. Otherwise, the hoop halves couldn't be joined.

Do-over. Or mulligan, if you prefer.

As I started clecoing the front and rear halves together, I quickly realized that I didn't have nearly enough of the silver clecos on hand. The preponderance of my collection was safely at home, sitting on the abandoned workbench and not doing much of anything to help. I'd have to go get them. Or, as I finally decided, just call it quits for the night. The roll bar is made of a heavier grade of metal that the for more malleable aluminum I've become accustomed to and is by its very nature somewhat objectionable to work with. It had taken quite a bit of cleco coercion to get the front and rear halves to even come to the negotiating table; arriving at an agreeable alignment was going to be more of a task that I was willing to bite off.

I went back tonight armed with the bucket of silver clecos that had been unconscionably lounging in the basement while their copper colored brethren did all of the heavy lifting. Slackers. They remind me of puppy Cabot, who has recently discovered the Rag Doll Defense when faced with a command to remove himself from a piece of furniture when he has worn out his welcome.

"Cabot, down!"

"Down? Me?? Surely you can see that I have suddenly lost all of my bones and muscles and therefore could not possibly remove myself from this extremely comfortable bed. Without skeletal structure for support and  musculature to provide motive force, it should be clear as day to you that I simply have no choice in the matter."

"Cabot! DOWN!"

"No, seriously. Just look at me! I'm lying here like a mass of hairy Jello. Why, the only way that I could conceivably be moved would be for you to... HEY! PUT ME DOWN!!"

My prediction of the previous evening was almost immediately proven to be true: it took a lot of convincing to get those parts lined up. A lot of cleco wiggling, metal pounding, and swearing finally got the parts closely aligned.

Looking ahead in the manual, I saw that these holes are to be eventually filled with the ubiquitous LP4-3 rivets. Odd, that, since those size holes have always been filled with the copper guys. Hmmm. That could only mean one thing. And that one thing is, of course, a whole lot of match drilling.

Yep! Match drilling, and lot's of it! The metal ended up being more receptive to the bit than I had thought it would be given my first impression of its nature as being inherently obstreperous.  First impressions can be wrong, I suppose. The drilling went easily enough. I finished just as the 6:30 dinner bell started ringing. Tomorrow will find me disassembling the whole deal for deburring. I also caught sight of a couple of words in the next step that sent shivers down my spine: machine countersink. Uh-oh! That's gonna be a big job!

Complications

It was inevitable, given that the whole "things happen in threes" doctrine seems, more often than not, to be an actual metaphysical rule of the universe. Or not, I suppose. I'm still waiting for the third. There must be some kind of expiration date on that kind of thing or it would be surpassingly easy to always match events into a set of three. We'll see how it goes.

So, what am I rambling on about? Well, it was one of those days when things that looked like they should be easy ended up not being so. It started at the paying job. I was putting the finishing touches on a new enhancement to a piece of software that we use to track a specific customer service process. The process in question has always been reactionary in nature, by which I mean we waited until a customer complained about a specific instance before taking action. These types of complaints are easily predicted, though, through a relatively simple analysis of data that we already have on hand. The reactionary approach worked fine for awhile, but the volume of cases has increased exponentially over time and is now threatening to overwhelm the lone person we have that works these cases.

Enter the IT dude. "Hey," said I, "let's shift our focus to a proactive approach. As part of my normal Wednesday morning data aggregation, I'll start tagging these potential cases and we can get busy on researching these issues before they get reported to us." Well, I didn't really vocalize that - I pretty much just jump in and do it. It turned out to be, as I had expected, a pretty straight forward process. There was the data, all lined up in a nice columned list on the screen. I put the data in the type of list that can be sorted just by clicking on the column header that the user would want to sort on. It was working great, mostly because it was re-used code that did the sorting.

It was tricky code early on - it struggled with correctly sorting values like $1.23 or 12/25/2010 because the computer (which I liken to a poorly trained monkey, with me playing the role of trainer) thought those values where words, not numbers. The most recent fix that I had applied fixed the "sort by date" problem by testing each value before sorting it to see if the DateTime object in my programming language could successfully convert the value to a date. If it could successfully convert to a date, well, I'd sort the values as dates. If not, they were numbers. Brilliant!

The new problem was with percentage values, more specifically percentage values of less than 10.0000%. Everything would sort just fine, except I'd see things like 2.2343%, 8.3423%, 4.3214%.  Clearly not correct.

Two hours of debugging later, I was mortified to find the offending line of code sitting directly under a comment that I had left in the sorting routine last time I had fixed it:

// I just want it known that I AM A GENIUS!!

I put that comment in there after (supposedly) fixing the date problem.  Who knew that the DateTime test was looser than Paris Hilton's overly hormonal chihuahua?

Thank goodness I'm the only one that ever sees this stuff!

All in all, it was a small-ish frustration tagged onto the end of what had been a fairly productive day. I thought I'd top the day off with a quick hour of work in the hangar. I scored a replacement for the lost headset jack nut for the RV-6 from the local mechanic and wanted to install that before I lost it, and I wanted to knock out the last page of Section 23. My hope is that the successful completion of Section 23, clearly one of the more demanding of the entire build, will help out when I get those 3:00 am anxiety attacks. You know, the ones where I wake up in a sweat wondering what ever made me think I could actually build an entire airplane! With my new response of "Hey, I got through Section 23, didn't I?" in hand, I can hopefully convince my middle-of-the-night critic to shut up and let me sleep.

The last page of Section 23 is where the first of the cowl hinges get installed. These cowl hinges have been the bane of my five years with the RV-6. I hate, hate, HATE these things. If you care to, you can find out why over at the Papa Golf Chronicles by clicking here. Or you can just take my word for it: the manner in which the typical Van's RV attaches its cowls is an unmitigated pain in the, uh, rear end. The RV-12 is no different.

It seemed a simple job. Cut off a couple of 10" lengths of the hinge material. Clamp a couple of the pieces onto the forward flange of the lower firewall. Match drill #30. Rivet in with the ubiquitous LP4-3 rivets.

I should know by now, and I suppose I do at some repressed subliminal level, that jobs that look easy most often aren't. It was a rather odd set of problems that I ran into. The first problem arose when I tried to clamp the right side hinge piece to the firewall flange. The firewall seems to be under some sort of compression force that makes it "oil can" (for want of a better term) in and out. In other words, the flange would either be pushed into the fuselage, or popped out of it. It wanted to be anyplace but aligned with the holes in the fuselage side skins. I couldn't cleco it or clamp it in place because the hinge strip wouldn't be able to sit flat against the flange with the cleco stems or the clamps in the way. I tried all kinds of things to keep that firewall from popping in and out; none worked. I eventually resigned myself to the fact that I'd have to start at the top of the hinge strip and clamp it down over the cleco stems in the middle set of holes. Doing that put a bend in the hinge strip, but I decided that the bend would be okay once I get the hinge fully riveted in place.

That turned out to be correct. Unfortunately, I was so focused on keeping the firewall flange in alignment that I let the hinge strip drift away from its intended position of being flush with the front edge of the flange. Down towards the bottom, the hinge strip angled in towards the firewall. That would never do; I know enough about these cowl hinges to know that they have to be pretty well aligned. I'd have to start over with a new piece of hinge strip. But I'd defer that until I had the left strip clecoed in. That's when I discovered (and I still can't figure out how this is even possible) that I had cut four right side pieces and no left side pieces. 

Normally this is when I would have started worrying about not having enough of the hinge material to correct those two mistakes, but I have plenty of the stuff left over from the repair to the RV-6 cowl. I cut a left side piece from the remaining supply. I had hoped that the left side of the firewall wouldn't do the same oil can thing that had plagued me on the right side, but to no avail. Still, having figured out how to address the problem helped get the left side done fairly easily. Going back to the right side, it too went as well as could be expected. All of this effort ended up taking more than two hours.  So much for an easy night at the shop!

But... I slept through the night without so much as a pang of anxiety.  Goodbye, Section 23!

Installing the airsickness detectors

It never fails. There we are cruising along at speeds normally reserved for Ferraris, which, as you can imagine, provides a fairly healthy amount of fresh air through the vents, when my passenger du jour starts fiddling around with the vents "trying to get more air." It almost always means one thing: he or she is starting to feel nauseous. It's not uncommon in any airplane, but the RV-6 seems to bring it on more often than more sedate rides. Those vents have prevented more than one smelly mess in the airplane since the warning is always taken seriously and pains are taken to return to the airport as quickly and smoothly as possible.

I don't know if the RV-12 will also induce nausea in inexperienced passengers, but just in case I installed the airsickness detectors today. Well, it wasn't actually just me; I had assistance today from Co-pilot Egg. I had prepared the pieces/parts a couple of nights ago and probably would have had everything installed by this morning if it hadn't been such a cruddy day at work that day. I was tired and irritable, and when it came time to countersink the outer doors for rivets I decided that I just wasn't in the mood. Bad things happen when I try to press through a black-cloud mood, so I deemed it to be a good idea to just forgo the pleasures of countersinking for the night.

Here are the parts that awaited us this morning:

It was a simple matter to cleco them together.

I demonstrated the countersinking operation for Egg, but she wisely demurred when offered the opportunity to try it herself.

The way these little doors will work is that a fixed screw will slide in the slot as the door is opened and closed. To enable smooth operation, the slots needed to be filed to remove some rough spots left over from the machining. Egg is comfortable with filing, what with having spend a hot, sweaty hour at Oshkosh filing a block of wood into a rough approximation of a propeller.

She already knows how to cleco, so after showing her the proper orientation of the parts (sadly, that was accomplished via trial and error - I got it in backwards on my first try, but Van's method of making it difficult to install things incorrectly caught my error) she clecoed them into place.

This is the fixed framework that will support the door as it slides open and closed:

The holes needed to be final drilled, a task that I found to be somewhat difficult. Because the slides only have two holes, removing one of the clecos for drilling allows the slide to move around. I didn't want the slide to move off center from the hole as I was drilling through the side of the fuselage, so I pushed it out of the way, drilled through the fuselage and frame holes, then moved the slide back into place and drilled through it into the newly drilled holes in the fuselage.

While I was drilling, Egg was reading ahead in the plans. "Ooh, you're not going to like what comes next," she said ominously, "We have to take it all back apart again." That came as no surprise; it was obvious that we'd need to deburr the holes. I let her take it apart and put it all back together after the deburring, and then it was time for some fun! She loves the pneumatic rivet puller.

While she was busy riveting, it was my turn to read ahead a few steps. I was somewhat taken aback by the way the screw gets installed in the slide/slot combo. Usually a screw in an airplane is installed from top to bottom. This one is not.

There must be a reason for that, but I can't figure out what it might be. Still, we do as we're told in the land of E-LSA. Once the frame was riveted in, we went back to assembling the doors. They too needed to be riveted together, but they use squeezed solid rivets instead of the blind rivets the frame used. I held the parts together while Egg squeezed the rivets. She doesn't like the rivet squeezer nearly as much as she likes the pneumatic puller.

I bolted the doors in place in the frames.

Here are the finished airsickness detectors, shown in both I'm-feeling-fine and I-ain't-feeling-so-good position:

Team photo: