Make work

I should be able to get the wing tab receptacles taken care of tomorrow. There is an RV-12 nearing completion not too far from here and I've arranged to go use its wing spar tabs to check the fit of the receptacles.

In the meantime I did a little prep work on some of the other parts that will get attached to the F-1206 bulkhead that the receptacles will be attached to. There was also a little dimpling to be done on the top of the bulkhead. It needed to be dimpled to match the dimples in the baggage floors. There were quite a few of those, but there were also holes that should not be dimpled, and to add to the complexity, the sets were not symmetrical. I took the easy way out: I placed the bulkhead into position on the baggage floors and circled the holes that should be dimpled and X-ed the holes that shouldn't.



There are four more baggage ribs that needed to be deburred, dimpled, and have nutplates installed. I knocked that out pretty quickly.



The next step is to rivet the bulkhead and ribs onto the center section, but I can't do that until the receptacles are trimmed/fitted and riveted into place. It was a good stopping point anyway as my brain was starting to send shut-down signals after a long day at work.

Wing? What wing??

I'm being disingenuous. I knew this step was coming, although in my defense I didn't find out about it until it was too late.

But before we get to that, there's the little matter of twelve nutplates to install. At least it turned out to be twelve; I had another of those cases where I just think too hard about the situation at hand.



It sounds easy enough: "Dimple the nutplates depicted in Figure 2." The drawing points directly at them. Well, half of them anyway, but it's a symmetrical job and it's easy enough to understand. For some reason, though, I thought that the holes for nutplates on the outer edges of the baggage floors were included in this step, but no nutplate size(s) or arrows pointing at them were in evidence on the page. It was the further instruction to "then rivet them to F-1221-L & -R Baggage Ribs and F-1224-L & -R Baggage Floors" that made me think those were included. When I run into questions like this, I just read ahead a few more pages to see if the parts in question get installed in a later step. I didn't need to go far - it's on the next page.

Yes, I know: you're supposed to read ahead anyway. I do, but not to the level of every single rivet and nutplate.

So, that was solved and it was a simple matter to cleco the nutplates in.



Easy, except....

I couldn't help noticing the uncomfortably close proximity of two of the nutplates to the bulkhead.



See that rivet hole between the cleco and the bulkhead? Pop quiz: how fun is that going to be to get at with the rivet squeezer? You know those things that give you a sinking feeling of dread in your stomach because you just know they're going to be a real ordeal but then they unexpectedly turn out to be pretty easy? You do?

Good.

This was one of them. It turned out to be just as easy to squeeze as all of the other rivets.





The center section gets set aside for a little while in order to prep a couple of parts. These are going to be part of the semi-circular receptacle that a tab on each aft spar of the wings slots into, presumably to provide alignment and a little more stability.





Those parts are really too flimsy to do much good on their own; they only provide a flange for a couple of far more robust parts. Those heftier parts were tricky to find. A few passes through the inventory sheet showed no sign of them. I finally found them in the inventory sheets that list the contents of the brown paper bags. Those bags are mostly for rivets, nuts, bolts, and other small-ish pieces-parts, so I didn't think to look there until all other options were expended.



And here's where the wing comes in, so to speak. (Did anyone get the joke there? These are receptacles for part of the wing, so by definition they are where the wing comes it. Get it? No? Oh well.) Anyway, the next step is to carry those little guys over to your wings and file the inner semi-circle to a nice, tight fit with the tabs on the aft spars.

Except, I have no wings.

Back when I was trying to decide which kit to get next, I had no idea that there was a dependency on having the wings when building the fuselage. Fortunately, it seems that the parts on the wing are pretty standardized and I should be able to get away with using someone else's wings. And I just happen to know at least two people withing an hour's drive that have RV-12 wings. It should be just a quick road trip to get this step done.

Looking ahead in the plans, it seems that I can fill a day or two with stuff that isn't dependent on having this part done.

It's been awhile....

It's been awhile. Since what, you wonder? Well, it's been awhile since I've worked for any length of time in the shop without having to drill out any rivets. A laudable accomplishment made possible by drilling one out last night.

I only managed a half hour working on the plane yesterday, but it should have easily been enough to finish the one thing I wanted to get done: squeezing in the rivets for the left side baggage floor, the very part that has given me a permanent nervous tick in my left eye. With the little reverse dimples caused from over-driving some rivets flattened out through the expedient of tapping them with a little hammer and the floor clecoed in place, it should have been a simple matter to just work my way down the row squeezing in rivets. And you know what? It was! So easy, in fact, that I squeezed one in that I shouldn't have.

Van's, realizing that they might face a mutiny from builders fed up with squeezing AD4 rivet after Ad4 rivet, courteously put one blind rivet in each of the left and right rows to give us a break from the strain of squeezing solid rivets. And a wonderful respite it would have been, too, had I been paying attention sufficiently to avail myself of the opportunity. I wasn't.

So, it had to be drilled out. On the plus side, drilling out a rivet that has responded to the compression of the rivet squeezer simply by leaning a little bit over to the side has to be the easiest type of rivet to drill out that there is. As opposed to, say, over-driven rivets. Those are the polar opposite.

Having gotten that out of the way last night, I was able to focus on getting the baggage ribs riveted into place. Having forced them into place with clecos previously during my misguided and ultimately detrimental attempt to use them to support the baggage floors, they slipped right into place this time around. I have a new tool in the shop that I was able to use to verify that I had them positioned correctly in the form of this nifty little 2.5 pound netbook:



I guess to be completely accurate I would say that I have this nifty little electronic gadget that I can use to verify that I either have everything positioned correctly, or I made the exact same mistake as someone else. Either way is fine; misery loves company too.

Having gotten the parts in place, I had to spend some time with my Super Secret Van's Decoder Ring figuring out the proper rivets to use from this drawing:



That one isn't really all that complicated - there are only two different types of rivet in play and finding the correct positions for the flush head CS4-4 rivets would be easy since they would only fit properly in the dimpled holes. What took a little more thought was the "Install all the rivets so that the manufactured heads are on the bulkhead." Just in case you're unfamiliar with the term, an installed rivet has two heads: the shop head and the manufactured head. An uninstalled rivet only has one head: the manufactured head.

It's pretty easy to figure out which is which: the head that gets made in the shop (either from being driven or squeezed in the case of a solid rivet, or pulled in the case of a blind rivet) is the shop head. The head that came on the rivet from the manufacturer is the manufactured head. I knew that - I was just trying to avoid the implications of putting the manufactured head inside the channel of the center section. It doesn't take long after realizing that you're reading it correctly to start to wonder just how that's supposed to work since there isn't a lot of room in there for cleco pliers, hands, and rivet pullers.

You know those things that give you a sinking feeling of dread in your stomach because you just know they're going to be a real ordeal but then they unexpectedly turn out to be pretty easy? You do? Good. Savor the memory of those, because this ain't one of those times. This is a royal pain. Getting the clecos in (and later, out) and wriggling the rivet puller in there to try to pull the rivets puts the sides and backs of your hands in constant movement up against the sharp edges of the bulkhead and center section. I haven't has this many lacerations on my hands since my ill-advised performance at amateur night at the Japanese Steak House.



Getting them in there was the hard part because there wasn't enough room to open the cleco pliers far enough to get them off the cleco. They came out a lot easier, but then I ran into the problem of the bottommost rivet. That one required the use of the little real-pain-in-the-rear-location wedge tool to make it a little easier to get the rivet puller in there.



Easier: it's not the same as easy. Just so you know.



Here they are, though, all in a row.



Those were the hard ones. After the rivets in the center section were done, it was a simple matter to place the rivets on the top of the floors.



Done at last!



Well, not really. There are some nutplates that have to be installed yet. And, of course, an entire airplane to be built around this core. But I'm done with installing the baggage floors and with the troubles I've had getting them in, that ain't nuthin'!

Too clever by 62.5%

Why not "too clever by half?" Rest assured, we'll get to that. We always do.

I posted a question on the ever-helpful Vans Air Force dot Net site to see if anyone could shed some light on the problem that I had with a gap being created between the baggage floor flange and the Center Section (which I am still capitalizing as a proper noun because I'm on a first name basis with that part, as in "You ^#%*$# piece of %$@# Center Section") when I riveted them together. I received a very accurate answer:

Looks to me like you are waaaaaay over driving the rivets.
If unable to do it with the gun, why not just do it the recommended way with a hand squeezer?

To which I replied:

With the #4s, I use a Cleveland Main Squeeze. It has an unfortunate bulge that precludes use close to another skin. I might have to try it with a "regular" squeezer if I can't get a handle on driving them.

Which is also accurate, as far as it goes. But we'll get to that. First, about the over driving. If you look at the shop head on the rivet as measured by the rivet gauge, you will see that it quite plainly is not over driven. If fact, it's perfect!



Or so I thought. But then I saw this reply:

If a rivet is slightly too short to start with and an attempt is made to squeeze it extra hard to achieve the correct diameter shop head, then the rivet will expand too much inside of the hole and cause the skin to pucker.

Well, there ya go! That's exactly what happened! You learn something new every day, it seems, even if it's sometimes painful to do so.

No time for self recriminations, though, as the immediate problem at hand was the removal of the over-driven rivet. I stewed about that most of the night last night, literally losing sleep over it. It was also a nagging itch in the far aft reaches of my brain as I tried to concentrate on a difficult piece of recursive code at work; I ultimately failed at that too and punted to a less elegant but more comprehensible solution. You see, if the location of the rivet makes it hard to get at with a rivet squeezer, it's going to be just as hard, if not harder, to get to with a drill bit. I had to come up with a plan!

I thought the best approach would be to get a 90 degree angle attachment for the drill, but the only ones I could find locally were big, bulky affairs that were larger than the actual drill. No help there. That left me with the only other option I could think of: use the super-long #30 drill bit. I wasn't overly excited about using it to remove a rivet since 1) I usually use a bit one size smaller than the hole to avoid enlarging the hole, and 2) it's hard to be precise with that much bit wobbling around. As it was the only choice, however, I resigned myself to it.

Once I tried to line it up on the hole with the Center Section lying flat on the table, I could see that it would be more accurate to put the Center Section up on edge and drill straight down. I couldn't do that, though, because the "feet" were keeping the baggage floors rigid and I couldn't push them back a little bit to give the drill some room. The crowding problem was exacerbated by the fact that the floors are at a less than 90 degree angle with the Center Section. I would have to remove the "feet" to allow the baggage floors to lean back out of the way.

Did a light bulb just illuminate over your head? Don't look up, I meant that figuratively.

"If I can lean these floors back to allow a drill to get in there," I asked myself (rhetorically - I might ask myself questions out loud, but it would be weird to answer them too, right? I avoid the temptation by only asking myself questions that I don't have to answer), "wouldn't that also have worked with the rivet squeezer? Even if it did suffer from an inconvenient bulge?"

Yes. Yes it would. And it also would have kept the clecos from scratching up the surface of the baggage floors, an event the instructions warned me about with the suggestion to put some tape on the rivet squeezer. I'm so smart that I decided that since I wasn't going to use no stinkin' rivet squeezer, I didn't need no stinkin' tape. But with the floor pushed past the 90 degree angle by the "feet," it came into contract with the edges of the clecos and got all scratched up.

That brings us up to "too clever by half."

I removed the baggage ribs, pushed the floors a little bit back to get them out of the way, and started drilling on the rivet.



Eventually, after slow and diligent drilling, the head of the rivet popped off.



Now on some rivets, that's all you need; the remainder of the rivet will pull right out from the other side. But an over-driven rivet is a different beast indeed. You see, what caused the gap in the first place was some of the rivet spilling out from the top of the hole between the two pieces of material, in effect forming another head. The new head was still trapped between the baggage floor flange and the Center Section. The other three rivets would have to come out too.

I hadn't counted on that. When I was leaving the house, I remembered that I hadn't brought a fresh battery for the drill. Wouldn't need it, I thought, since I was only drilling out one rivet.

It died halfway through drilling out the third rivet. I was 62.5% done with drilling out the rivets when I had to stop because I was too clever to go back and get the fresh battery. Finally! Too clever by 62.5%.

Rather than head back home to get the battery and run the risk of getting trapped, I thought I'd try squeezing a few rivets into the other baggage floor to see if it was going to go any smoother than the first has.



It did. Although... the rivets are still a little too short. I don't think I'm going to be able to squeeze a regulation size shop head onto them. Maybe with the rivet gun....

Nah, not a chance.

This his how the flange is supposed to look:



They all went in fairly easily, although I found that there was a trick to getting the first little squeeze started with the floor leaning forward to keep the flange flush, then pushing the floor back to allow a straighter squeeze after the rivet was set enough to hold the flange in place.



Note the scratching from the clecos. Bummer, that. I think mine is by far the ugliest center section in the brief history of RV-12 building. That's kinda like my golf trophy: Worst in the League. I won that one pulling away. Of course, I couldn't hide my shame by painting the trophy - the same is not true for the baggage floors.

You think that side is ugly? You ought to see the other guy!

One of the effects of over driving the rivet is that it creates a kind of reverse dimple in the flange where the rivet material pushes it out of the way. I took the floor back home to try to work it back to flatness. After escaping an hour later to get back to the hangar and cleco the floor back onto the Center Section, I found that it still needs work.



I'm not sure I'll ever get it as nice and tight as the other side, but I'm going to give it at least one more try. I think it's always going to be at least a little ugly, though.

Gaps in my knowledge

I wanted to get an early start on riveting the baggage floors to the Center Section this afternoon but one thing just kind of led to another. Getting up at 0515 every morning starts to take a toll right around mid-week, so a nap kinda just happened. Then I decided that I wanted to put the "feet" under the baggage floors to keep them from drooping and putting unwanted torque on the baggage floor flanges as I was trying to rivet them. (PARENTHETICAL NOTE FROM A TIME TRAVELER THAT HAS COME BACK FROM THE FUTURE: DON"T DO THIS!) That took far longer than expected and brought me hard up against dinner time. It wasn't until 7:00 that I was able to leave for the hangar.

I was back by 7:30.

The "feet" that I referred to above are the F-1221-L/R, F-1222-L/R, and F-1223-L/R Baggage Ribs that will support the baggage floor. The first trick with them is to get them correctly oriented. The drawing is not at all difficult to interpret, but I have to get the actual part aligned and placed in the same position as it is in the drawing. You know those shape puzzles they have on aptitude tests? If those were the only criteria for success in this world, I'd be filling a position at the very bottom of the Village Idiot, Inc. org chart. And my prospects for advancement? Poor. Very, very poor.

Getting the Center Section and flaccidly dangling baggage floors positioned only involved half a dozen turns, flips, and rotations before I was trying to figure out which direction the Baggage Ribs went. I'll cut to the chase: find the holes in the center of one of the edges of the rib and put it furthest away from the Center Section, and don't worry that the holes don't all line up with each other:



I don't want to talk about how long that took to figure out.

Part of the difficulty in getting the ribs correctly positioned was that they don't fit very well. It took a bit of cleco coercion to get them to snug into position up against both the Center Section and baggage floors. As with situations like this before, what worked best was to start out at the edges and work in towards the Center Section. The flanges that cleco to the baggage floors were relatively easy; it was the flanges that attach to the Center Section that were the toughest. Eventually, though, success!



It actually worked, too. The floors were nicely supported on the ribs were under them.



I loaded the whole thing into the trusty Subaru and drove over to the airport. It's rare that this happens, but the guy that hangars his Baron next door was there getting ready to push his plane back in. He doesn't seem to fly it much. Anyway, as is the usual case I gave him a wave and, as is also universally the case, I was completely snubbed. It's like I'm completely invisible from 20' feet away. Amazing. Probably one of those guys that, if he goes to Oshkosh at all, thinks the whole thing would be better without all of those pesky EAA types running around.

I dug out my Gucci-orange rivet gun and loaded up an offset rivet set to angle in towards the hard-to-reach rivets.



I missed a bit on the focus, but you can see how the bend in the rivet set will help me get the rivet gun itself up away from the surface of the baggage floors when I try to set a rivet. So, I was finally ready to rivet!

So how did I end up being right back home by 7:30?

Well, I can't figure out what is causing the flange to bend out and cause this gap:



Worse, I don't know what to do about it. I'm reasonably sure that step #1 is "drill out the rivet," but I'm kinda keen on knowing what step #2 is going to be. Just driving in a new rivet is only going to do the same thing. Perhaps the gap is acceptable (and that is the answer I would truly love to hear), but without knowing one way or the other I couldn't see the value in proceeding with more riveting.

Slow, steady progress

An ocean is a big thing to cross, and I'm always surprised when I remind myself that a ship traveling at no more than 20 measly knots can cross one in something like three days. At only 20 knots, you'd think it would take weeks. But the thing is, they don't stop; they plod along during 24 out of 24 hours. At a slow, steady pace they eventually get there, and with no stationary periods, they get there quicker than you might guess.

Which is all to say that while I did get to work on the airplane tonight, I didn't get much done. There is a reason that I wanted to be building this thing in the dead of winter, and that reason has a name: Yard Work. After a long day at the paying job, in the spring I often have to come home only to start on my second job: maintaining the yard and outside environs of the homestead. This afternoon the weather conditions were prime for putting down weed killer, "prime" being defined as "not raining, and not likely to for a few days." It's a big yard at slightly over an acre and a half, so it takes a goodly amount of time and effort to get it covered.

Once done with that, it's pizza night and I'm the cook. 'Tis fair: I cooked pizza professionally (minimum wage counts, right?) for years while I was in high school, so I'm the recognized expert at it. Nice to be recognized as being good at something, right?

So, after yard work and dinner it's time to consider making my way down to the shop. Which I did, only to be reminded that I had stopped my previous work at one of those head scratching moments. I do a lot of head scratching these days, most of it figuratively, fortunately. The question at hand pertained to dimpling some holes in the baggage floors. Five lucky holes were selected to be dimpled #19. Fine, as far as it goes, but none of my borrowed dimple dies are labeled as being size #19. At least that was the problem I thought I had when I quit working. Today it was pretty obvious that the holes that were to be dimpled were themselves a #19 size hole. Ah, that helped!

Still, why just those five? There were plenty of other #19 holes that would go wanting of a dimple, after all. My theory? These are the holes through which screws will be installed to hold the baggage floor down, and they look like they're in the area of the fuel tank. These screws will need to be flush to the baggage floor if they are to sit under the fuel tank while the rest of them can be permitted to stand proud above the floors. It'll be a long time before I find out if this theory is correct.

After those holes were dimpled, and it only took a minute or two, I had to determine which of the many remaining holes were #30 and #40 size because those too needed to be dimpled. Those sizes I more or less recognize on sight these days, so I grabbed the Sharpie and marked them to be dimpled. Those holes that were to remain unmolested got a X drawn over them lest I get carried away with the dimpling.



Again, it was short work to get them dimpled. It's really quite easy when the holes are right on the edge of the skin. The next step is to rivet the baggage floors to the Center Section. I found it easier to cleco them into place vertically rather than horizontally as shown in the drawings. As seems to be the norm with riveting in the Center Section, different size rivets are involved and it pays to mark the territory to avoid mistakes. They're #19s, in case you're wondering.



I could tell by how hard it was to get the clecos in that these were going to be tough rivets to squeeze because of their tight location up against the baggage floor. The plans suggest putting tape on the rivet squeezer to keep it from scratching up the floors, but with the squeezer I'm using that prophylactic won't be enough. I know Van's tried to design this thing to not require any rivet pounding, but sometimes the right tool for the job is the only choice. These rivets are going to have to be driven, and I'm going to have to haul the Center Section back to the hangar (its third trip!!) yet again.



Not tonight, though. I could feel that I was getting "stupid hands," a malady that I get late in the day when I'm tired and may have had one too many cups of coffee to get me through the work day. Stupid hands get sloppy and make mistakes, as I've learned to my detriment, and it's better to just call it a day.

This ocean will eventually get crossed, and while it will be a steady pace that gets it done, it's not going to be a non-stop ride.