More firsts

More "firsts" tonight.

Last night, I received a welcome influx of high quality aircraft building tools from Co-pilot Rick so tonight I was able to really dive in and clear out some of the backlog of work. Sounds odd to "be behind schedule" already, but I've had parts waiting for deburring for lack of good tools.  Before moving on to anything new, tonight's first task was to work through the backlog. The ScothBrite wheel, some small files (which I already had but for some reason never thought to use), and a neat edge deburrer got everything cleaned up and ready to go in just about an hour.

I had primed the rudder hinges last night so they were ready to be riveted together, but I wanted to squeeze a few practice rivets first. I see on other bulder's logs that they just grab a piece of the scrap metal that came with their kit to test and/or practice with, but I can't figure out where they're getting it. It must be the lower number RVs that include that. With the -12 kit, the only spare metal I have so far is shavings from drilling and deburring, and I vacuum those up every night. I made a quick run to the hangar to grab some leftovers I kept from metal projects I did while I was taking a few A&P classes and brought those back to the shop to play with.

I'd been warned that squeezing #4 (1/8" diameter) rivets was tough, but the first practice rivet went fine. As did all but one of the ten that I needed to do to finish up the rudder hinges. The fifth one I did started to bend as I was squeezing it.



So, my fifth squeezed rivet was rapidly followed by my first drilled out rivet. Ain't that grand? Fortunately the drilling out of the bent rivet went easily and well. I'm sure there will be plenty more. Here are the completed rudder hinges:



With step one finally completed, I moved on to finishing up step two, which is match drilling all of those holes in the big spar that forms the tail end of the vertical fin and supports the rudder. Many, many holes to be drilled. It was here that I realized that I still don't fully understand the strange dialect spoken by Van's manual writers. One step said to match drill the #40 holes near the bottom of the part. The drawing helpfully showed that area, along with a tag that said "MATCH DRILL #40 - THREE PLACES."

All well and good, that, except for one thing: there are six #40 holes there. But... the holes could be considered to be in three pairs of two, if one were desperate to understand just exactly what one was being told to do. It's interpretive, see?

And that would have been just fine. I would have drilled the six holes and spent a night sleeping the deep, restful sleep of a man with a clear conscience. Except for one thing: the next step was to "MATCH DRILL 3/16" HOLES - FOUR PLACES." There were four holes. Arranged in two pairs of two. For consistency, one would expect that to be described as "TWO PLACES."

I drilled all four without compunction, but now I'm wondering about those doggone #40 holes!

It was nice to be making good progress again, but there were some moments that threatened to ruin my mood. None of them were all that big in and of themselves, but a series of minor annoyances can have a profound impact on your reaction if you were to (hypothetically, of course) do something as dense as dropping your drill on the floor and breaking your #30 bit. Just saying that could be the case, mind you. It's not like I could ever be that clumsy, right?

From the mail bag:

Brent said...

Looks like your squeezer is the main squeeze. That thing is crazy good. AD4 rivets are tough with a Tatco or avery squeezer, but the cam in the main squeeze makes it easy.

I actually prefer my main squeeze over the pneumatic squeezer.

DaveG said...

Brent -

Exactly right - it's the Cleaveland Tools Main Squeeze. At $400 for the squeezer and dies, I doubt if I would have bought it myself given the relatively low number of solid rivets in the -12, but I was able to borrow it from Co-pilot Rick. Good tools and good buddies willing to loan them out make it all sooooo much easier!

Evangelism

On any topic where there is a meaningful amount of room for opinions, you will eventually run into evangelism. For example, most people agree that 2 + 2 = 4, and anyone having a different belief is simply ignored. There simply isn't a lot of wiggle room in whether you believe that simple equation to be true or not. Subjects of any importance whatsoever are seldom (rarely?) as binary as the true or false proposition of mathematics, though. On any more complex subject, the strength of personal opinions will fall roughly into one of these categories: uncertain and don't care, uncertain and open to suggestion, certain but willing to tolerate other opinions, and so certain that no other opinion can or will be entertained. That final stage is what I define as evangelism.

There are three demographics that are well known for the high degree of evangelism in their ranks: the religious folk, the political junkies, and pilots. Get any group of pilots together (and by 'group' I mean two or more) and get them talking about flying (which is easy since that's all they will want to talk about anyway) and you will soon see that at least one of them is evangelical on at least one topic. Some of the more common are high wing vs. low wing, straight-in pattern entry vs. 45 degree entry on downwind, whether or not pilots that check in with a new controller by saying "with you" should be thrown into a pit filled with 1000's of rabidly hungry Chihuahuas, nose wheel vs. taildragger, and Lycoming vs. Continental engines. When it comes to people building airplanes, one of those evangelical topics is the question of whether or not to use primer.

There are two questions, really. The first is how much (if any) to prime the interior parts of the airplane and if so, what primer to use. On the prime-every-surface side are people that live in a corrosive environment, typically those on the coastal regions where there's a lot of salt in the air. The why-bother crowd are folks that live in dry, arid regions. Me? Well, I live on the coast of a corn field. It's not dry, but it's not salty either. That puts me in the group that generally think it's enough to prime parts that have had their alclad coating removed. We've already seen a part like that here at Schmetterling:



The inside part of those assemblies have had the alclad layer sanded off on the sides to smooth them out. I'll want to prime it.

Having decided that, the second question came up: prime them with what? Naturally, there are a dozen answers to that. Two-part epoxy and hours of preparation is at one extreme of difficulty, a spray can of self-etching primer from Napa Auto Parts after a quick wipe-off with some soapy water is at the other. The Napa spray can being on the easy side, in case you didn't figure that out on your own.

Here's what I decided on:



Anything else is overkill. Most of the 40+ year old Cessnas and Pipers you see at any midwest airport are not heavily primed and they're still going strong. In forty years, I'll be 88. Even with an LSA, I doubt that I'm still going to be flying or in the least bit concerned about the state of this airplane.

In addition to buying a can of primer, I also made a trip to Harbor Freight to pick up another mover's blanket. I'm going to be working on a part with all of the blue protective vinyl removed and I don't want to set it on an unprotected surface, especially one with so many protruding screw heads that could put a deep scratch into the vulnerable aluminum. Cost of the blanket? $4.99. Final tally at the Harbor Freight cash register? $42.

Cashier: "Did you find everything you were looking for?"

Me: "Yes, plus another $37 worth, thank you very much."

That happens every single time I go there.

After my morning errands, I picked up Wingman Ted, who is mid-way through building an RV-10 and his Co-pilot Wayne at the airport. Wayne is also going to be building an RV-10. They were looking for somewhere to fly and decided to come visit the Schmetterling Aviation shop. After a nice visit and lunch at BW3 (where I got to see the only good part of the O$U - Purdue game), I dropped them back at Bolton and headed back to the shop.

Today's job was to start drilling the holes in the spar cap I worked on yesterday. And again, there was a little head scratching. Basically what it came down to is whether the instructions that said MATCH-DRILL #30 THESE HOLES meant just the holes I have circled in red or if it included the blue holes too:



It's as if I'm learning the nuances of a new dialect. I understand the words, but their true meaning sometimes still eludes me. In this case, it was a simple matter to look ahead in the plans a few pages and definitively determine that I was to drill both red and blue.

The directions say that you should drill and cleco every fourth hole. That went well enough after the first hole. What happened on the first hole? Well, the bit drilled through the metal and then kept on going, right through the new blanket. The bit pulled a bunch of blanket material back up through the hole. Oops! After that I started putting a small plank under the part as I drilled it so the bit would have someplace less irritating to come to rest. The every-fourth-hole method results in a nice zig-zag pattern:



The next step is do the same on the other side. I can't do that as I am out of clecos. I could shuffle around the handful that I have, but the shop floor will be closed tonight anyway for spouse date night. It'll wait until tomorrow, unless the weather is nice for flying. My RV-6 misses me.

I read ahead a little bit and found that once the other side is drilled, it all gets taken apart for deburring and general clean-up. After that the directions say to "Match-drill the rear spar flange holes."

To which I said, "Huh? Wouldn't I have just done that?" After an embarrassingly long time thinking about it, I realized that no, no I hadn't. I had drilled the web holes. It's another example of that new dialect I'm learning. The 'web' is the wide part of the spar, the 'flanges' (there are two, actually) are the thinner, bent over parts. The sides, if you will.

I'm on hold now until Co-pilot Rick brings over some tools. He will be a welcome addition to the shop; my current assistant Hogarth really isn't all that into it:

Friday!

Although it was an abbreviated work week after taking Monday and Tuesday off, it felt like a full week. The first day back after even just a couple of days off is stressful as pent up demand for my services hits full force as soon as co-workers start coming in, but even after burning all of Wednesday getting caught up I was able to get some good work accomplished. I'm in the middle of at least a half dozen long- and short-term projects, but with only two full working days left in the week I concentrated on small stuff.

Even with only two days to spend I got two new customer-facing reports done, and the technology I'm using for these (Microsoft C# and Crystal Reports to programmatically generate PDF files, if you must know) is somewhat brittle so any progress at all is gratifying. These particular reports turned out very well, if I do say so myself, and I'm particularly proud of the one I did today. The one I did yesterday was mostly to spec, although a clever two-line approach for each data row that I came up with answered a thorny issue having to do with horizontal page space. The one I did today was my own idea, and although it used the same data as the other report, it presented it in an entirely new way that garnered a few of the "oohs" and "ahs" that IT folks just live for.

Somewhere during the half hour commute home I went through my daily transition from SME (subject matter expert) to VI (village idiot). In this case, the transition to "airplane builder" was especially jarring. You see, I'm very much still in head scratching mode. I look at the plans and instructions with the same level of comprehension my dog Hogarth demonstrates when he sees me perform what to him are the minor miracles of turning darkness to light and summoning forth water on demand.

So, here's where we're working:



The red ellipse is around the rear spar of the vertical stabilizer. You might also call it the tail fin. The blue ellipse is around the part that I worked on tonight, the VS-1212A Lower Spar Cap. The VS-1212A and VS-1212B come in one big part called the VS-1212. The VS-1212 has to be separated into the A and B components. That's pretty easy; I just cut them apart with tin snips and filed the leftover tabs off. The part that had me perplexed was this:



"Remove Area Shown Hatched" is pretty easy to understand, but what I didn't know was where to draw the line, so to speak. There were no markings on the part to show where to stop removing metal:



Once metal is removed, it's darn hard to put back on, so I wanted to think about it awhile! After staring at it for awhile, I decided that I could just use a straight edge to continue the slanted edge all the way down to the end of the part like so:



Then I just traced a line with a Sharpie marker:



Once that was done, it was just a matter of clamping it to the table and filing it down to the line:



There are a still lot of rough edges to be deburred, but I clamped it into place on the spar just to see if it looked reasonably right:



I'll either deburr it tonight or wait until tomorrow morning. Once it's deburred, it has to be drilled to match the holes pre-drilled by Van's into the spar. That should be pretty straight forward. I hope to have it done before noon when I will sit down to watch THE Ohio $tate Buckeye$ play the Purdue Boilermakers.