Categories: all aviation Building a Biplane bicycle gadgets misc motorcycle theater

Sat, 19 Sep 2020

Building a Biplane: Paint Jobs

Although I'm still a decade away from having anything to paint, I occasionally think about what I'd like this eventual biplane to look like. To that end, I've been slowly collecting coffee-table books on golden age aircraft, and the COVID lockdown has given me enough time to go through all of them, learning about historical planes, but also keeping an eye out for paint schemes I liked.

When people ask me what I'm building, I have a photo downloaded on my phone, which I show. It's from the article, Glenn's Charger Flies Again, and I like how it shows the sweep of the wings:

As I have looked at this plane over and over when showing it to people, the red color has grown on me. I wasn't averse to it before, but between repeatedly looking at this photo and a flying experience I had a few years ago, I'm pretty sold on red.

What happened a few years ago was that I was in Norbert, my little Champ, flying out to Hoquiam on the Washington coast, for a FATPNW event. The weather was on the low side, with a solid overcast at maybe 4000 feet, so it was perfectly safe to fly, but there wasn't a lot of "up" available. The clouds lowered as we got close to Hoquiam, and were at more like 2500 -- still safe, but again, not much "up" available. I landed late for the event, and most people were ready to leave, so I only ended up being there for a few minutes. This was fine, as I was really in it for the flying, and have always had a hard time socializing with people I don't know.

One of the planes there was a Cessna 152 which had been painted bright red. I thought it was kind of garish when I saw i on the ground, but that changed completely when we flew out as a little group.

It was me (black and green), this 152 (bright red), and a couple other planes painted in the sort of generic white-plus-colored-stripes themes that are so common in the general aviation fleet. We had all departed in the same wave, and flew in something like a very very loose formation as we departed the Hoquiam area, over low rolling hills.

Being in a very loose sort of formation, I was pretty keen on keeping visual track of all my fellow aviators, to make sure we didn't get too close to each other. We were still half a mile apart in all cases, but that's pretty close, in airplane terms.

As I was tracking these various planes, every time I looked for the 152, I could find it immediately. It popped against the dark green scenery, with its bright red paint. The white planes were harder to spot. It got me to thinking: white is the same color as clouds and a lot of things on the ground. Almost nothing on the ground is bright red (certainly there are cars, but visually they're almost invisible because they're so far away). That bright red paint job made that 152 so much more visible than anything else.

With that thought in my head, plus repeatedly seeing the picture of Glenn's Charger, I've found myself inclining to a red paint scheme for my Charger.

I'm also a fan of black, though I think it's not a very good airplane color, just because it can disappear into the background with such ease. What about a majority-red paint job, with black accents? Sounds pretty good. I had put together a functional but not pretty model of the Charger in X-Plane, so I spent a few hours figuring out how to wrap my ugly grey model in a slightly prettier color, and came up with this, which is useful mostly as concept art:

This was pretty good, though obviously very basic. Not sure about the N-numbers, they'll probably end up being the 2" numbers that I'm allowed to use rather than these 12" numbers. But the basic idea is there.

Then, when I was flipping through my various coffee-table books, I came across this Waco CTO on page 36 of Wings of Yesteryear: The Golden Age of Private Aircraft by Geza Szuravy, and I thought, yes, this is the look:

The exact shade of red may or may not be correct, but I love the tapered black stripe with the little harpoon-head at the front, and the gold pinstriping.

I certainly can't promise my final paint will look anything like this, but at this stage in the process, I like it a lot.

Posted at 12:21 permanent link category: /charger


Sat, 12 Sep 2020

Building a Biplane: Cutting Spars

The most expensive single part in the wing of a Marquart Charger is a wing spar. This is the long piece of wood which runs from the root of the wing out to the tip, and is the backbone of the wing, if any creature had two backbones at once. There are two spars, see, so the analogy only sort of fits.

In any case, the spar is a piece of aircraft-grade Sitka spruce (and as soon as you describe anything as "aircraft-grade" you can just see the dollar-signs rolling up in vendors' eyes), either 11 or 12 feet long depending on whether you're talking lower or upper wings. It's an inch thick by about four and a half inches tall for the front spar, or about two and a half inches tall for the rear spar.

One of these glorified two-by-fours costs between $110 and $150 apiece, depending on length and size. Because of their length, shipping a single spar and shipping all eight spars costs about the same: around $200 when I ordered mine, more now. However, even more than their monetary cost is the cost in time. When I ordered my spars a few years ago, it took Wicks Aircraft 6 months to finally realize they couldn't get good enough spruce any more, and cancel my order as they got out of the spruce business. It took Aircraft Spruce, the only company left in the country (as far as I'm aware) who was capable of filling the order, another 6 months or so to finally ship my spars out to me. (No negative reflection on either company, this is a really tough market to deal with.)

The problem is that aircraft-grade lumber is rare. The loggers have to carefully lower an old-growth Sitka spruce tree to the ground, either with a crane or a helicopter, to avoid compression fractures as it falls. It has to be treated carefully, and it needs to be nearly perfect: no knots, no sap pockets, perfectly straight grain of an adequate density, etc. All of which is to say that you can't just call up the lumber yard and order a replacement spar if you mess one up. Wicks said they got a new shipment in every week and in 6 months didn't find enough wood of a high enough quality to fulfill my order. Talk about overhead.

As a result, I've been half-terrified of actually cutting my spars ever since I got them. If I mess one up, not only am I out $300+, I'm down for around 6 months while I wait for a replacement. "Fortunately," I've been learning all about the expense of aircraft parts, so $300 barely causes an eyebrow-twitch any more as I ponder $1,500 radios, $3,000 ADS-B transponders, and $27,000 engines. (I knew it was going to be this expensive before I ever started, but it still amazes me sometimes how much this stuff costs.)

So, how am I going to approach the actual cutting of my spars? Very very carefully, that's how.

I need to do a number of operations to the spars, but the first and most frightening to me is cutting the top and bottom angles. Because wing spars are part of an excitingly curvy airfoil-shaped wing, and to simplify the construction of the ribs, they're cut at an angle on the top and bottom surfaces, rather than being square.


The front spar's profile


The spar fits into the rib in the red section, which shows why it needs to be angled

The main reason it's the most frightening is that it involves the use of the table saw, which is nothing more than a raw saw blade poking up out the top of a table, without all the sensible guards and precautions of a nice bandsaw. It's so easy to accidentally shift a little bit and carve a big divot out of whatever you're cutting. Not a huge deal when you're cutting a piece of crappy plywood for a theatrical set that's going to be up for 6 weeks, but fairly daunting when it's aircraft-grade spruce on the line.

The way to prevent this from being a problem is to lock that fancy 2x4 down as much as possible. Make it so there's literally no dependence on the steadiness of my hand as I guide a twelve-foot piece of lumber through the saw. This is the idea I got from another Charger builder, who sent me some photos of the following idea:

  1. Acquire a long piece of steel, at least ten feet long, preferably longer, to act as a fence
  2. Set up the fence on the table saw at the appropriate distance for the cut to be made
  3. Add multiple "platforms" along the bottom of the fence, to support the lumber being cut
  4. Add feather boards to the platforms to hold the lumber in its exactly correct position
  5. Add feather boards above the blade to keep the lumber pressed down to the table
  6. Practice on a small piece of spar material (or other 1" thick wood) until the cuts perfectly fit in rib openings
  7. Cross fingers, kiss blarney stone, rub lucky rabbit's foot, etc.
  8. Cut the real thing

Tonight, I gathered together all the pieces needed for steps 1 through 5, or at least those I already had on hand. A few months ago, I acquired a twenty-foot-long section of rectangular steel tubing, which was pretty ridiculous to bring home on my little truck, but it works great now that it's here. The platforms were made out of the very useful piece of MDF I've been slowly nibbling on over the last few months. My clamp-related oniomania has paid off, and I had plenty of clamps on hand to get everything set up. I only have three feather boards and I'd like to have five, so I'll have to find two more, and the Kreg feather boards are pretty awesome, so I'll be getting more of those. Finally, the rolling stands I got a while ago made excellent end-supports to keep the fence from rotating due to the unbalanced weight of the little MDF platforms.

This is the final result of the first attempt to set most of it up:


The Very Long Fence set up on my little construction table saw


Close-up of the business portion; no cut distance set, this was just the first shot at the idea of the thing

It probably won't work in this position, as the steel is only 20 feet long, so there needs to be about two and a half feet of space off either end of the fence for this to work with a 12 foot spar. Fortunately, this isn't the final setup, just the first attempt, and it'll be shifted around and reorganized so it will work -- moving the saw so it's sitting diagonal to the space will provide plenty of room. Another time I'm glad the whole shop is on wheels.

I picked up a couple of 2x6s to trim down into faux spars, so I'll get a couple good shots at doing "the real thing" without actually doing the real thing. Fortunately, I have the shiny new bandsaw to resaw the 2x6s with, so I can get closer than my previous attempts using the table saw for resawing, which never turned out quite right.

I suspect that this is going to result in a video as well, but no promises. I find that I'm usually interested in taping the big scary stuff (or at least the stuff I find big and scary), just so I can get through it, have proof I did it, and can show everyone else that it's not as big and scary as I thought it would be, which is invariably the case.

Posted at 23:23 permanent link category: /charger


Thu, 03 Sep 2020

Building a Biplane: Painting: The Next Frontier

For the last few months since our collective COVID lockdown started, I've been working away at the brackets and wedges and other pieces that make up the wings of a some-day Charger biplane. I called Seattle Powdercoat in March asking them about their sandblasting services, and told them it would be "a few weeks" before I'd have things ready to bring in. Oh, it is to laugh.


Completed brackets

Here we are in early September, and I finally have all the brackets done that need to be done (almost: the wing root brackets that will attach the lower wings to the fuselage are waiting for later due to the specific fitment issues they will have, which depend on having both wings and fuselage ready for everything to be hooked together). I am, at long last, looking down the barrel of my longstanding nemesis:

Painting.

I've never much liked painting. It's messy and you have to wear disposable clothing and it's so easy to get wrong, and so chemical, and it just never clicked with my brain the way other parts of building things did. Yet, if I were to hire out the painting for this whole biplane project, it would add tens of thousands of dollars in labor. And lots of other people are able to paint their own planes, so why shouldn't I?

The basic idea I've got is as follows: use Stewart Systems paint (which is all waterborne, and substantially less toxic than other systems), and when it comes time to paint the big pieces, put together a paint booth inside the shop by using plastic sheeting to enclose a volume that will fit all the pieces necessary. I'll start with their EkoPrime and EkoCrylic paints for these little brackets. This all presupposes a bunch of stuff, though.

Equipment. To get set up for a job like this, I need to invest in equipment. Specifically, a nice spraygun, which is a several-hundred-dollar item. That's ok, it's not too bad, but on the back end, it demands a capable air compressor. My current compressor is a $100-special pancake compressor I got down at the big box store 10+ years ago, and is emphatically not up to the job. Stewart recommends a compressor capable of 13 cubic feet per minute (CFM) at 90 PSI, and my little compressor is probably capable of around 2 CFM. Maybe 2.5. The cheapest option that will be close to the mark is a 60 gallon, 3.7 HP compressor for $560, at 11.5 CFM (though I have it from another builder that this compressor is definitely up to the job, which is reassuring). To actually make the mark and meet or exceed 13 CFM, the cheapest option I've located is about $1200.

More important than the money, though, is the installation and space. If I were to do it strictly right, it should be bolted to the floor, and plumbed into a system of copper or iron pipes that are installed into the building, doubtless a week or more of work for me. The compressor itself is supposed to be placed 18" from the wall, meaning it would take up about three feet of space in the tightest corner I could pack it into, which is a huge amount as I ponder where I'm going to put four wings and a 20 foot long fuselage and still have any working space left over.

Fortunately, another builder opined that he set up his giant compressor on a wheeled platform, and that makes the whole thing much more palatable. It's not as ultimately safe as being bolted to the floor, but at least on wheels I have the ability to place it where it's going to be least in the way. Everything else in the shop is also on wheels for specifically this reason, so it's a pretty compelling idea.

On top of the compressor itself, there's a noticeable investment in filters and water separators and hoses and connectors to make it all work. My current compressor setup is extremely basic, though it's enough to power a small spraygun with the addition of an appropriate filter to get rid of condensed water.

Leaving aside the question of the compressor (for I will most likely live with my tiny compressor for now, since the volume of painting I need to do at this point is very small, and doesn't require the massive air capacity of the big boy), I have essentially zero experience spraypainting anything. To be sure I've shot my fair share of rattlecan paint, but I never cared if there were runs or surface imperfections. Only on one project, perhaps 15 years ago, have I attempted to make a real professional appearance using rattlecan paint. It turned out alright, but I barely remember what I did, so it's not much help in guiding my hand now.

Because my quantity of painting is so small, I'm not excited about building a proper paint booth in the shop. Thus, I decided I'd try building a micro paint booth, which is mostly a stand to hang parts from, with some plastic inexpertly draped about it.

We'll see how it works. On Biplane Forum advice, I'm going to remove the back plastic so it doesn't all just blow back in my face, and do the whole thing outdoors so I don't accidentally paint everything in the shop with a light dusting of primer.

So, I have a compressor, a tiny spraygun, with a smaller one on the way (one of those little pencil-shaped guns that modellers use, recommended for its frugal paint use and lack of overspray), hose, connectors and a painting rack. I have a good filter on the way. It's not the right setup for doing Real Painting™, but I think it'll work for what I'm doing.

The final step is to do some test spraying with my setup, and make sure I have some idea what I'm doing, and that everything I've got is goign to work like I want it to. Most of these brackets will be hidden away inside the wing, so they don't need to be beautiful, but they do need to be adequately protected from rust, so I want to have some confidence that my technique won't simply have the paint flaking off immediately.

Then, at long last, I will be able to take all these parts into the sandblaster and have them cleaned up for painting. You know, "a few weeks" later.

Posted at 15:51 permanent link category: /charger


Sun, 19 Jul 2020

Building a Biplane: Getting Unstuck

For the last four days, I've been trying to figure out how to make this part:

[Image showing
plans to make the tie-down ring, part number -282, for a Marquart
Charger]
The -282 tie-down ring

It looks simple enough on the plans, all innocent and perfectly drawn. Yet it's taken me four days so far, 17.5 hours of work, with more to come. Most of these brackets I've been making take maybe 4-8 hours to sort out. But this one's special.

The journey starts with: How to bend that hoop? Quarter-inch 4130 steel is no slouch in the strength department, though with a long enough lever it's easily bent. My first try was just to clamp the thing in a vise, perpendicular to a length of stout 1" tubing I had lying around (for the 1/2" radius bend), then bend it over the tubing by grabbing the long end and giving it a shove. This worked, but the resulting bends had a disagreeable curve to the "straight" parts that I didn't love. My math was also poorly understood, so it took a few tries before I got the right size, and I only had 17" of the stuff to work with. Finally I gave up and decided I could live with the poorly-bent hoops, just so I could make progress.

So, hoops done, check. I had the plates already, thanks to my various Ken Brock bracket kit purchases. I held the hoop up to the plate and tried to imagine how I'd actually hold any of this together. It's pretty fiddly, and clearly a quality jig was in order.

The first problem with the jig is that the space between the plates needs to be 2 1/8". I had 2" square tubing, which I'd used to make jigs for other brackets, but I had to find that extra 1/8" of thickness somewhere. I have some 1/16" thick sheet lying around from a previous project (making the drag strips, which I ultimately scrapped in favor of wires), so I decided to weld two layers of that onto my jig, which should work out to exactly 2 1/8" thick.

Of course, it did not. It was a little bit thin for some reason, and since these brackets tend to shrink a little after they're welded, I really didn't want to start off too small, or I'd never get the bracket onto the wing when the time came. So I did the only reasonable thing I could think of, and ran a weld bead down each of the 1/16" strips to make them a bit thicker.

[Image showing the welding jig with weld beads built up]
The welded-up jig

Then it was a whole lot of filing to get them back down to the right size, after I managed to crash the head of my milling machine when the jig leapt up into the cutter and stopped the works very quickly indeed -- I still need to open that thing up and replace the busted gears. But I got it to the right size, and I'm going to have very odd musculature in my arms when this is all over.

However, my skill with a file is not expert-level, so the strips are only about right, they're not perfectly flat. I decided this was an acceptable compromise because it's all getting welded anyway, and striving for perfection there is an exercise in frustration thanks to the expansion and contraction of the steel as it's heated and cooled.

In any case, I took my imperfect jig to the drill press, and carefully drilled out the hole that would locate the side plates. Not carefully enough, though: the entry hole was perfect, but the exit hole was at least 1/16" off, probably because I'd been resting the jig on those imperfectly welded and filed strips. So I tried a trick I've never done before, and welded up the hole, having to weld from both sides. It worked, to my amazement.

None of this addresses the original problem, though: how to deal with that floppy hoop that has practically no mechanical connection to the plates until it's welded. Finally, I decided that I'd make a crossbar with slots in it that would hold the hoop, and the milling machine came out again (I'm telling this out of order; I made the crossbar before the head crashed). That piece at least was pretty easy to make.

The final problem to solve (so I naively thought) was how to make sure the side plates, which are held down by a single bolt, couldn't rotate. When installed on the plane, they interlock with a big round piece, but I didn't want to have to make that up for my jig. Instead, I ended up making a little shelf out of metal for the legs of the plate to rest on.

[Image showing the finished welding jig]
The finished jig, in the ready-to-weld setup

Finally, late in the evening, having fussed with the spacing on the imperfect hoop for several hours off and on, I turned on the torch, and applied heat to metal, tacking the hoop in place. As soon as I did, I realized that my design was lacking, and there was no way to get the tacked bracket off the jig. The crossbar was locking it in place, and I ended up (the next morning) having to saw the ends off the crossbar, and file rounded ends in it so it could get past the plates while still holding on to the arms of the hoop.

This was ok, because a discussion on the Biplane Forum had convinced me that I needed to try making stainless steel hoops. The idea was that there was no way to chip the paint off them, and they wouldn't rust. There followed a feverish study of stainless steel properties and welding techniques, and a quick order to the metal shop. I was glad to be able to get it on Friday afternoon, so I could have the project to work on over the weekend.

I had called my dad to discuss the stainless steel (he knows more about stainless than I do), and he reminded me that I had a better way to bend the rods than just clamping them next to a tube and pushing hard: I have a press. And, I realized, I built a really moosey tailspring rebending tool which might just work as an improvised press brake. The idea is that you use the press to push on the center of the thing you want to bend, while it's resting between two bars, or a V-block, or something like that. The idea struck me, so I spent most of Friday trying it out. Fortunately, I got three feet of the stainless steel rod, because I made bad bend after bad bend (not the press brake's fault, I just kept getting the math wrong). Eventually, though, I ended up with two perfect hoops, exactly the right size, and with lovely square corners. Shown here before the ends were trimmed, so their perfection isn't quite as obvious:

[Image showing two nicely bent-up tie-down hoops]
Hoops!

I decided, wisely, that before I would commit my hard-to-reproduce side plates to this project, I would try welding some of my incorrectly bent stainless rod to some mild steel, just to see if I could do this dissimilar-metals welding well enough to put on an airplane.

I welded the first hunk of rod to a failed experiment that was a sort of box of square tubing, which was certainly a decent stand-in for the side plate. Once it cooled down I hit it with a hammer a few different ways, finally sticking a piece of MDF (not the strongest material, but the right size, so why not?) through the center of the box and tried pressing the rod away from its plate. With one moderate hit of the hammer, it ripped right off.

Well, that's not good.

I tried again, on a different spot. Same thing. I made a smaller test piece, thinking maybe the big box was sucking up too much heat. Nope, same thing. For some reason, the welding rod I was using to build up the weld was porous and quite weak.

Just to make sure it wasn't my technique for welding a rod to a plate that was at fault, I tried the same thing with a piece of the 4130 that didn't get bent well. Making the same test, the MDF was destroyed, and it barely moved the rod. But it did move it enough that I could flip the piece and whale on it with the big hammer. It bent, then bent further, then bent almost double. The weld held, finally just starting to tear as the rod took its last few hits. That was much more like it. That's a weld I'd trust to hold down an airplane, or jack up an airplane.

[Image showing an amusingly bent piece of 4130 rod welded to a
mild steel structure]
At least the weld didn't break

So, the stainless steel experiment was a bit of a bust, but at least I found out before making a bit expensive mistake, or even worse, putting it on the plane and thinking it was doing well until the one thing that would doubtless be a catastrophic failure.

Now I just have to find more 4130 rod. But once I have it, I have the perfect bending technique all lined up and ready to use. Five days to produce two tie-down rings? Why not.

Posted at 00:43 permanent link category: /charger


Sat, 04 Jul 2020

Building a Biplane - A Quickie

In my video on making aileron pivots, I said I'd spent 16-some hours so far, and expected to spend 20 more before the pivots were all done. I've finished them (or at least gotten to the condition I was thinking of when I made the 20 hour estimate, which means they're ready to be sandblasted, painted, and finish-reamed, so still several hours from being done) as of last night.

I've spent some time revamping the build log (coming soon), and while I was dinking around in the database this morning, I decided to see how many hours I'd actually spent building aileron pivots.

sqlite> select sum(hours) from events where date >= "2020-06-05 19:27:02";
57.7

My original estimate? Less than 40 hours. Actually? Almost 60, over the course of almost exactly a month. It's silly, but I find this very amusing.

Posted at 10:15 permanent link category: /charger


Sat, 20 Jun 2020

Building a Biplane: Some Updates

I've been making good progress on the Charger build lately, and wanted to share some news.

The first thing is that I've made a dashboard showing my build progress. It was amusing to put together, and it's interesting to see in charts and graphs how I've been working on the plane. Having to take 2019 off due to lack of shop space made a pretty healthy dent in my progress.

The other thing is that I made a video about a tiny part of the build process, which may or may not interest you.

This shows one of the many many little steps that go into making the aileron pivots, which are deceptively simple-looking on the plans. It's just these three arms, how bad could it be? As I mention in the video, it's going to take something like 40 hours to go from looking at the plans to having 12 functional pivots in my hand, and that's not even counting getting them sandblasted and painting them, which is a completely separate adventure.

As someone commented about the build when I was describing it to them, "Oh man, even the details have details." Yep, the top-level step of "make 12 aileron pivots" touches on all sorts of questions: how to buy steel that hasn't been made for decades; what's the best compromise among the available sizes of steel; where to find that size; justifying paying $18 a foot (not including shipping or tax) for a weirdo size of steel that is also going to make the plane unnecessarily heavy; where is the steel after the seller put the wrong zip code on the box; how to cut steel; how to cut steel so it's square; how to cut steel so it's got the correct angle to the cut; how to figure out the correct angle to the cut (CAD to the rescue); how to locate two holes in a part so that they have the exact same placement on every piece; how to assemble the pieces once they're cut; how to build a welding jig for assembling the pieces once they're cut; how to make a welding jig that will lock everything into place, and then let it go once it's welded together; how to weld these two pins so they actually match the piece they're supposed to locate... It never ends.

To be clear, this is a big part of the fun: taking a job and breaking it down into its component parts, and then doing all those little jobs as efficiently and well as possible. In the end, you have a finished product that reflects all the hours and effort. It's slow going, but it is rewarding, eventually.

Posted at 23:44 permanent link category: /charger


Tue, 26 May 2020

Building a Biplane: Welding Brackets

I have reached a significant milestone, but it's not exactly about building an airplane. No, what I've done is finally finished the shop.

Of course, the shop will never be finished-finished, but it's now good enough that I can stop thinking about it, and get on with building an airplane. The door is replaced, the drywall is done, the electrical is inspected and passed. Finally.

Which leads me to the next phase of building a biplane: welding brackets. A typical bracket assembly looks like this:


Lower rear interplane strut bracket

The bracket starts life as three separate pieces: two -202 plates, and one -220 filler piece. The challenge is to assemble it and weld it so that all the holes are still lined up and the bracket is straight. Welding tends to make pieces move all over the place, because the welded metal heats up and expands, then contracts when it cools down, just a bit smaller than before it was welded.

This means that the pieces to be welded need to be held in a solid fixture or jig, that keeps them from wandering too far. They'll never be perfect, but perfection is always the goal.

So, my job is to come up with some way to keep these plates in line with each other while heating them to white hot. My first thought, which I'm glad I was talked out of, was to make some MDF pieces (a type of engineered wood that's basically sawdust and glue pressed together), which would basically take the place of the spar and wedge blocks shown above.

MDF is probably rigid enough, but the heat would have set it to smoking badly, and might have caused the structure to weaken enough that the welded pieces wouldn't have been held tight. So that was out.

I was resistant to making them out of metal because I didn't have any metal to speak of. As we live through a global pandemic, I'm trying my best not to venture out, but I decided this was probably worth it. I ordered some square tube stock from Online Metals and picked it up the next day.

So, the jig for this piece needs to do a number of things. It needs to:

I surveyed the jigs that needed to be made, and identified two main spacings I would need: 1.5 inches, and 2 inches. Thus I ordered lengths of those two sizes of square tube, so I wouldn't have to try to build up the right thickness. It turns out I missed the 1.25" brackets that go at the root end of the wings, but I'll work on those later.

The jigs would also need a flat piece across one end, for the spacer to rest against. Somewhere in this process I found the small collection of welding steel I had packed up so carefully when I moved, and decided I'd use the 4130 sheet left over from making the drag strips for this, since it just needed to provide a reference surface, not bear any weight.

What I came up with was this:


Partially completed -202 bracket jig

That's only partially completed, it would eventually have a second hole drilled, so that it would hold the brackets like so:


-202 jig holding all the pieces of the bracket

This plan worked out pretty well, but it took me a couple different jigs before I figured out the best technique for making them, specifically for drilling the holes so they were straight, and would align with the bracket plates. I'm making heavy use of the mill now, simply because it allows me to be so precise. It's almost certainly overkill, since these pieces are getting welded and will necessarily distort themselves all over the place, but you might as well start from a place of precision if possible.

The end result has turned out well, and the brackets look pretty good:


Finished brackets

The biggest problem I actually ran into is that the first set of wing brackets I bought a few years ago turns out to be coated in cadmium as a rust preventative. It worked really well, those pieces are all rust-free. Unfortunately, welding cadmium-coated metal is a good way to severely damage your health, and getting rid of the cad plating involves either muriatic acid, which is quite dangerous, or burning it off, which pollutes and is quite dangerous.

I figured out they were plated when I welded up my first piece, and noticed the horrible black smoke coming off the metal, and the yellow fume that seemed to stain near where I had welded. I clued in enough to put on a respirator after making the tack-welds, but that was not an ideal situation to be in.

Fortunately, one of the Biplane Forum members recently sold me a second set of brackets, duplicating and expanding the first set. This new set turns out to be not plated with cadmium. So, they're a trifle rusty, but clean up nicely, and don't rapidly poison me as I weld them. Win-win, honestly.

I'm on my way to getting my brackets done, another small step accomplished in the impossibly large project of building a biplane from scratch.


Slowly chewing that elephant, one bite at a time

Posted at 00:02 permanent link category: /charger


Tue, 21 Apr 2020

Building a Biplane: Improbably, a Sort of Milestone

When I describe the process of building a biplane, I invariably describe it as one that's going to take "ten to twenty years," because that's just how life is. Most credible estimates suggest that doing something like building a Marquart Charger from scratch is a 3000-5000 hour job. I'm probably going to end up on the 5000 hour end of things (particularly if I try for a round engine, but that's a discussion for a different time).

However, taking the middle of that estimate, at 4000 hours, may be a reasonable best-guess.

I mentioned a couple entries ago (and more than a year ago) that I was maintaining a log of all the work I've been doing. I promised to make it more than it started as, and I've taken the first step along that path: I added a "total hours" row at the bottom of the table. It was a lark, but it reveals a sobering truth: despite my jests about being at the very start of the process (which it truly feels like I am), I'm actually making significant progress.

As I write this, the total hours number stands at 388.8 hours. That is to say, nearly 400 hours, which would be about 10% of the build.

I'm 9.72% of the way done with building a Marquart Charger.

It's not a huge number, sure, but it belies the sense I've had for a long time that I was just farting around, making no real progress. No, in fact, I have a complete set of wing ribs finished, an appreciable portion (I'd say around 90%) of the wing parts built, on hand, or poised on the edge of ordering (the cross-brace wires are waiting on me properly inventorying my need for more spruce bits so I can combine the surprisingly expensive shipping), and am in the final stages of shaping the last little bits and pieces that need to be fabricated.

Once I have the cross-brace wires and fork-ends ordered, all that's left is painting a bunch of steel brackets and profiling the spars before I can start assembling the wings in earnest, at which point I suspect things will seem to move very quickly, compared to the visually unimpressive stack of wing ribs.

There's always more work to do (at least 90% to go), but it's nice to take a step back and appreciate that I really have made some good progress.

Posted at 14:21 permanent link category: /charger


Wed, 15 Apr 2020

Building a Biplane: Back In the Build

My last entry was pretty brief, with the simple aim of showing you my build log. Looking at the log, and at this journal, you would be correct in guessing that there was some kind of an interruption.

In late 2018, it was becoming obvious that I'd have to move soon, which would mean giving up the shop I'd put together for my Charger build. It would mean an unknown delay until I could find another house, ideally with a shop, and resume thinking about this insane plan of building my own full-size biplane.

And yet, here we are. I've found my new house, and I managed to find one with a 2-car garage that was ripe to be converted into a workshop. That process has taken far longer than I wanted it to, but is nearly coming to an end as I wait for the new garage door to be installed -- the whole COVID-19 situation means I'll probably be waiting for a while, though.

When I left off on the project, I felt that my next logical step was to profile the spars, and start assembling a wing. I had the ribs built, and all the compression tubes. I hadn't yet ordered the cross-brace wires, but I've still got that shopping cart loaded up at Aircraft Spruce and ready to go. I had found all the internal wing brackets in a Ken Brock kit on Ebay.

However, there was a significant piece missing. The wedge blocks.

Long story short, the Marquart Charger has a very classy-looking 10° sweep to the wings, but all the ribs and bits that go inside are arranged parallel to the fuselage. This means that you have to make up that 10° difference somehow. This is where the wedge blocks come in.

The use of the wedge blocks is pretty obvious. For instance, in the diagram below, you can see how the wedges, in green, are used to make a 90° surface against the wing spar, shown in blue:

So, that made a lot of sense to me. Wedges, cool.

Then my eye would always trace back to this cyclopean horror:

I had no idea what this thing was trying to tell me. For years, I would see it, and immediately get confused. It looked for all the world like a single piece of wood, that I was somehow supposed to cut up to form all those wedges, and it just boggled me to no end. How do you cut that -238 piece from the corner of the -239 piece? Wouldn't it leave a huge gap? How are you supposed to cut all those angles without the saw taking out its kerf and leaving you with undersized pieces? It just absolutely confused me.

Finally, shop nearly done, but not quite done enough to go around cutting thousands of dollars worth of spar material and assembling wobbly half-completed wing structures which might need to be moved (inviting any number of broken wing ribs), I decided to bite the bullet and ask for help with this wedge horror. Not that I have been shy about asking for help before, but it's always a bit of a struggle to admit that I don't understand something that everyone else seems to get.

So I fired up a graphic editor and cut out the section of plans I'd be posting about, but something about it made me pause. Suddenly, out of the blue, the picture that had for all time looked like a white vase on a black background snapped around, and became two human faces, facing each other with a white space between them.

It wasn't showing a single piece of wood. It was showing all the wedges overlaid on top of each other. My brain felt like it was going to explode.

Instead of drawing out six side profiles and six face profiles, with the attendant measurements for each, Ed Marquart had done the sensible thing and drawn them together to save space and drawing effort. This sudden understanding was, I must say, a huge relief.

Here is an annotated diagram with improved dimension lines, which shows in red how to interpret the dimensions for making a -239 wedge:

Looking over the plans and dimensions, it looks like I've probably got enough off-cut spruce to make most of the larger wedges, though I'm going to order some 1/4" thick stock to make the -238 wedges, since there are so many of them.

Now, I just have to figure out how I'm going to cut all these extremely sharp angles. I've started on a sled for the table saw, similar to this design. I don't have any MDF lying around at the moment, so I'm starting with some not terribly good plywood as a base. I'm pretty sure a sheet of MDF is in my near future, but it's good to experiment with the technique for the moment.

Honestly, I'm just excited to have something I can do during COVID times that doesn't require a helper, like the spars, and can be accomplished with the shop in a relative state of disarray while I wait for a new door. Progress is finally being made again, and it's a gratifying feeling after such a long delay.

Posted at 13:37 permanent link category: /charger


Sun, 16 Feb 2020

Thoughts on the Reality of Fantasy

Starting last year, I suddenly got back into role-playing games after a nearly 25 year hiatus. In college, I played all sorts of RPGs (all this is the tabletop variety, not videogames), and dropped the habit once I got into the "real world," on the presumption that no one would have the time for it.

In any case, I now find myself DMing a campaign of Dungeons and Dragons, and playing in another, both of which came together more or less because I waved the "I want to play RPGs" flag on Facebook, and got a huge response.

One of the things that's come to my attention is that we apparently experience events from the games as being in some way real. I have operated on this assumption as I run my game and play in the other, but it had remained an abstract thought until this last weekend.

In the game where I'm a player, my character, Cass, is a 17 year old half-elf who has lived her last ~4 years as a street urchin, after escaping from an abusive home siutation. Half-elves are generally outcasts, being neither fully human nor fully elven. A couple years ago, she realized that she was developing magical powers, the source of which is completely unknown to her. In game-mechanics terms, she's a wild-magic sorcerer, which means that her spellcasting comes from within, and may occasionally spark chaotic, unexpected magical effects.

Critically, she's quite small: under 5' tall, about 90 lbs (with a healthy weight of about 110, which she'll probably reach with sufficient food), and not terribly strong, with a strength score of 8 on a scale of 3-18, where 10 is average.

As I play her in the game, I've been doing what I felt was a reasonaby good job of getting into the mindset of someone who is not at all like me, in temperament, physical presence, or outlook. What would an Ave Rat do? (For readers not from Seattle, Ave Rats are the homeless teens who hang out on the street near the University of Washington campus, colloquially known as "The Ave.")

In yesterday's session, we found ourselves at liberty in a new city in our fantasy world (a homebrew world that my co-DM Jordan and I are creating together). We spotted an urchin who looked like they were being chased, who disappeared into an alley, but no one was chasing them. Curiositiy piqued, Cass followed, but found the dead-end alley empty. Nyx, Cass's friend and fellow street urchin, found a tunnel that they may have disappeared into, and we followed it, popping out into a storeroom. We didn't find anything, but made a mental note that we might want to check it out further.

Later in the day, with fresh mysteries to solve, Nyx and Cass decided to go check out the storeroom again, to try to find any clues our previous urchin may have left behind. At Cass's insistence, we kept the remainder of the party away, so as to be more sneaky and quiet.

Sneaking in was trivial, and once inside, we rolled terrible Stealth rolls, and pretty much immediately someone came to check out the noise. A man unlocked the door and walked in, spotting us as soon as he was in.

With the heart-racing feeling of a cornered animal, Cass darted forward and attempted to hit the man with a shocking grasp attack, which, if it hits, delivers a surprising amount of force -- this is the only spell she's confident she can cast every time. Her plan was to surprise him then dart away down the tunnel, hoping to forestall any attempt to follow them.

The attack missed. The man grabbed her and she squirmed and tried (and failed) to shocking grasp him over and over until he completely immobilized her. He didn't realize what she was trying to do, taking it to be normal attempts to kick or punch rather than a magical attack.

During this time, Nyx fortunately kept her head, and persuasively argued that we weren't trying to steal anything, and had in fact been trying to help the urchin we'd seen before, who seemed to be in distress. Cass was enveloped in a fully-developed fight-or-flight response, and utterly unable to move. The man, and moments later, his boss, were willing to listen to Nyx, and after Nyx tried to calm Cass a bit, set down the struggling girl. Cass and Nyx demonstrated the previously-unsuspected tunnel into the storeroom, and the shop owner took us to her office.

The discussion was brief, and essentially consisted of "Don't break into people's shops, please." She let us go thanks to Nyx's silver tongue, and we were escorted to the store's front door, passing the varied goods present in any general store.

This sequence of events, at the slightest remove, was patently stupid. I, a 40-some year old man, would never, ever act in this way. But in the moment, with my mind placed as firmly as possible into the brain of an imaginary 17 year old street urchin, the choices were clear as day: the man was a threat, she knew she was caught where she wasn't supposed to be, and her only thought was how to escape right now. She was overconfident about her ability to use shocking grasp, sure that it would fire off every time she tried to use it, forgetting that you also have to hit your target for it to work.

After we were released from the shop, Cass was shaking with reaction, the immobilization by the shop hand the absolute worst response he could have made, from her point of view -- it recalled her pre-urchin past, and dropped her into the horrible mental space that called into being. She had to sit down in the street and let it all wash over her for a few minutes, before she could really continue on.

We stopped the session shortly after those events, out of time for the day. I went off to my next event, a friend's birthday party. As I sat waiting for others to arrive, having gotten to the bar early, I realized: I was shaking. Not a lot, but I was not my normal steady-feeling self.

I thought back on the past hour, and realized that I'd also had tensed shoulders as my character was being restrained against her will, and was feeling that shaking even then. I had described the character's physical reactions because I actually felt them in myself. Only an echo of the character's reactions, to be sure, but I felt them. Somehow, I had experienced a trauma trigger reaction even though I, the player, never had the trauma in the first place, and didn't experience the triggering event "for real."

As I self-consciously examine my memories of the event, the mental image of Cass, caught up in the arms of a comparatively burly shop hand is much clearer than the sight of my DM or the other players, at that moment. I don't see through her eyes; it's a disembodied memory, as if I were watching a movie, but the slightly dusty storeroom, his leather apron, Nyx's pleading voice, the sense of mindless, wild-animal panic: these are all more "real" than the reality that was in front of my eyes.

This is hardly a revelation, of course. I linked a study above that suggests empirically that this is all fairly common among RPG players. Even so, it hints at the awesome power latent within role-playing situations. We have the opportunity to become heroes in a way the real world does not offer, except on rare occasions (magical abilties aside, of course). We can experience crushing defeats and bounce back. We can be the people reality doesn't allow us to be.

Dungeons and Dragons is experiencing a resurgence at the moment, and I suspect that an element of that newfound popularity is this very ability to do heroic things that reality denies us. There are many factors, of course, but the chance to experience things that are otherwise unaccessible is surely one of them.

Posted at 18:59 permanent link category: /misc


Thu, 16 Jan 2020

Ohm's Law, You Trickster

I'm nearing the final phase of my garage refurbishment, which means that I now need to mud the drywall. Nothing fancy, just plugging up the cracks to complete its ability to resist fires. However, this means that I need it to be at least 55° F inside the garage, and to maintain that for roughly 24 hours while the mudding compound dries/cures.

Of course, the weather in Seattle just took an Arctic turn, and the first half of this week was entirely below freezing, with many (largely unfulfilled) threats of snow. However, it's still been in the 20s.

Clearly some supplemental heat was called for.

I have a 1500 watt milkhouse heater, though I know from past experience that it doesn't do a whole lot for even a one-car garage sized space in the winter. Imagining that it would help with a two-car space with an uninsulated roof (that's a project for a different day) was ludicrous.

So, I loaded up the website of my favorite big box store, and started trolling through reviews of 4000-5000 watt 240v heaters.

I noticed an odd trend: every heater would have a surprisingly large proportion of reviews that read roughly like this:

This heater is worthless. Turned it on, and it barely blows any warm air at all. Save your money.

After reading enough of these, along with some other reviews that suggested maybe the complainers were plugging into 120v instead of 240, I found my curiosity piqued. Surely, thought I, if you plug a 240v heater into 120v, you'd get half the performance, right?

Then I remebered: Ohm's Law is a tricky bugger. What if it was a quarter?

Ohm's law explains the basic behavior of electrical circuits with resistive loads, such as our heater. It says that the voltage (in volts) is equal to the current (amps) times the resistance (ohms):

V = I * R

You can rearrange this to figure out any of the terms. So I wanted to know what the resistance of my chosen unit was. I knew it was a 4000 watt heater, that it ran on 240v, and that the spec sheet said it consumed 16.7 amps of current at 240v. Plugging those numbers in to Ohm's law to figure out the resistance, we get:

R = 240 / 16.7

R = 14.37 ohms

Cool. So now, what happens if we know the voltage and resistance, but want to find out the current? This is important because power (watts) is determined by the voltage times the current. This will determine if the power in watts is halved at 120v, or does something else.

So, calculator out, and we figure:

I = 120 / 14.37

I = 8.35 amps

Oooh, lookie there! It no longer draws 16.7 amps, instead drawing just half that amount. The resistance of the heater hasn't changed, but half the voltage actually pulls half the current. That means that indeed:

120 volts * 8.35 amps = 1002 watts

Compared to its full-voltage spec, the massive 4000 watt heater will only put out a thousand watts when plugged into a normal 120v circuit. Less than a hair dryer, and there are probably real-world inefficiencies that make the 240v heating element even less effective at 120v than the pure math would suggest.

And this is why you always check the specs of the thing you're buying, and don't just wire up a new outlet to fit the weird plug of this big appliance you just got (I can virtually guarantee you every reviewer who complained of lackluster performance made two trips to the store: one to pick up the new heater, and another grumbling and cursing to buy the funny-shaped outlet the new heater demanded, stupid heaters).

Posted at 15:22 permanent link category: /misc


Wed, 16 Oct 2019

A Snippet of Worldbuilding

I'm building up a new campaign world for a D&D game I'll be running soon, and I have finally produced some work from that effort which I can share without spoiling anything.

The initial adventure location is in a Slavic-inspired region of this world, and I needed a folktale for one of the situations I was setting up. As is usual in these cases, I just started writing to see what would come out -- all I knew was the title, and one of the pivotal moments in the story. It's always fun to see what my feverish little brain comes up with in these cases.

Thus, I present you the quickie first-draft story of the Witch in the Woods, written roughly in the style of traditional folktales:


Once, long ago, there was a young girl named Maria Antipova, who had an infant brother, Leonid. Their parents had died, and they were living as best they could in their parents' cottage in the woods. Maria would gather firewood during the day, and sell or trade it to local villagers in exchange for food. It was a hard life, but they were surviving, and the local villagers gave them a good rate for the firewood, for they felt sorry for the pair.

One day, a withered old woman dressed in fine traveller's clothes came to their door, and begged for some food as a weary traveller. Maria invited her in, and gave the old woman what she could. It was meager, just porridge and a very small mug of warm milk, and she apologized for the poor fare. The old woman demanded more, having become very imperious once she had stepped over the threshold. Maria gave her more milk, but the old woman was not satisfied. Leonid started crying, for Maria had taken food away from him to give to the old woman. She became angry at the baby's cries, and said, "Silence that whelp, or I will sell him to the fairies!" Maria tried, but Leonid was so hungry, and he would not stop crying.

The old woman could not be pleased. Finally she demanded, "Give me a bed to sleep in, for I am tired, and give me wax to plug my ears against that child's screeching!" Maria gave her her own bed, and a piece of wax she was used to chewing when the hunger was great. The old woman went to sleep in Maria's bed, and Maria stayed with Leonid, consoling him to no avail. Eventually she fell asleep holding the baby, perched atop the little milking stool. The fire died down to embers, and the night passed.

In the morning, Maria awoke to find that the old woman was gone, and so was Leonid. Frantic, she searched through the cottage but to no avail: Leonid was nowhere to be found. She ran out of the cottage to the path, and called out for Leonid, but there was no answer from the woods. Just then, a woodcutter was passing with his axe, and he heard Maria's calls. "Who do you call for, girl?" he asked. She recognized him as one of the villagers would would trade milk or butter for wood. "My brother is gone! An old woman was here, and when I woke up this morning, Leonid was gone, and so was she!"

The woodcutter said, "I saw an old woman riding a butter churn through the air this morning! She was holding something in her hands." Maria thought this must be the old woman who had spent the night, and asked, "Was she wearing fine clothing?" The woodcutter said she was, then said, "She is Taraga, the Witch in the Woods. I'm afraid your brother is gone, never to be seen again." Maria asked him where the Witch lived, and he said she lived over the mountains in a wood far away. "You had best not go to her, for the way is dangerous and she will eat your brother before you can reach her."

Maria was undeterred, and gathered her few things into a cloth and cast it across her shoulder. She tucked her father's meat cleaver into the waistband of her dress. Before she could set out, there was a knock on the door, and a kindly villager woman stood without. She said, "Maria Antipova, my husband tells me you are going to Taraga, the Witch in the Woods. Take this shawl, and it will keep you warm. And take this apple, so that you do not hunger. My husband sends you his stoutest boots, so that your feet can travel without tiring." Maria accepted the gifts gratefully, and set out.

The way was hard, the path rocky. Soon she was climbing up a mountain, and clouds gathered into a storm. "Maria Antipova!" said a voice from the clouds, "Go no further, or I will sweep you from this mountain!" The storm rained down on her, and Maria put up her new shawl, and stayed completely dry, for it was a magic shawl. The mountain grew ever steeper, but Maria continued on, baring her teeth into the storm. "I am not afraid of you, Taraga!" she called into the sky. The clouds thundered in response.

Soon the mountain was past, and Maria was slogging through a swamp. She tucked up her skirts and pressed on over the boggy ground, the boots keeping her feet dry, for they were magic boots. Soon the swamp had passed, and she was climbing over great boulders, but she felt she was getting closer. As night closed in, she made a small fire between two boulders and ate her apple until she was no longer hungry, but the apple was still whole, for it was a magic apple. The fire died down to embers, and Maria tried to sleep, but the ground was hard.

She heard a snarl near to hand, and rose again, crying out, "Who is there?" A wolf's face appeared out of the gloom, and said in the old woman's voice, "Maria Antipova! Go no further or I will eat you up, as surely as I will eat up your tiny brother!" Maria stood and held out her father's meat cleaver. She said, "I am not afraid of you, Taraga, and I will rescue my brother whether you like it or not!" She swiped at the wolf's face, and it ran away.

The next morning, she made her way past the boulders, and came upon Taraga's hut. It was surrounded by a fence surmounted with children's skulls. "So, you have found me, Maria Antipova," said Taraga. "Soon I will add your brother's skull, and maybe even your own, to my fence." Struck with an idea, Maria said, "Let me in, for I am weary with travelling!" The old woman let her in to the hut, where Maria saw Leonid lying in a baking pan in front of the oven, which was heating up. "Give me food, for I am hungry!" said Maria Antipova. Taraga grimaced and hissed, but gave Maria what food she could find: a cabbage and an onion. Leonid woke up and started crying at the loud voices in the hut. "Silence that child, or I shall steal him and sell him to the fairies myself," said Maria Antipova, and the old woman was forced to comfort Leonid. "Give me a bed, for I am weary with travelling," said Maria Antipova, and the old woman was forced to give up her bed to Maria. "Now leave me to sleep," said Maria Antipova, and when the old woman turned around to leave Maria to sleep, she cut her in two with the cleaver.

Gathering up her brother, Maria gave him the apple to eat and fixed the shawl about him so that he would stay dry. Together, they left Taraga's hut, and walked back to their own cottage in the woods, where they lived to a ripe old age and were happy with each other.

Posted at 21:31 permanent link category: /rpg


Sun, 26 May 2019

The New-House Contractor Shuffle

As previously related, I found a new house to live in after a few months of searching. I can no longer complain about that being too long, having run into someone who was looking for 2 years before she and her boyfriend found their new house.

Anyway, my new house (provisionally named Brinkley Manor, so I don't have to constantly refer to it as "the new house I just moved into") was not without faults. Particularly, much of the interior paint was patched with the odd bit of spackle and generally looking well-used; the main floor bedroom (which I was planning to occupy as bedroom and office in one) had some quite dingy beige carpet in it; and the main floor bathroom's floor was acceptable but uninspiring vinyl.

Now, I know what happens when I approach this kind of project: I plan things out for way too long, when when I finally overcome the mental inertia to get started, discover that I completely failed to plan for 20% of the stuff I should have known about, and then I can only work on it evenings and weekends. It's probably better now than it has been in the past, but either way, I decided that as long as I was splashing around money like a drunk with his Maddog 20/20, I'd hire contractors to do the work for me. This way it would get done quickly, and well, and wouldn't involve 20x more trips to the store than I had previously considered feasible. And, I could actually move into my new house in a reasonable amount of time.

I knew all this more or less as soon as I saw the house the first time, and I discussed the possibility of getting my contractors in to prepare bids ASAP, ideally before we closed, which was still a month or more in the future. Normally, you can ask the seller's agent if you may have permission to let contractors in to do this kind of scoping-out of work once you're under contract -- after all, they're not touching the house, just figuring out what needs to be done. Since this was a vacant house, there was no complication of asking the residents permission. Easy peasy.

Alas, no. The seller's agent was remarkably hard-nosed about the whole thing, and refused to even consider letting my contractors in before closing.

We had one opportunity where it could happen whether the seller wanted it to or not, which was the walk-through. This is where the buyer gets to check out the house to make sure it's still in the condition promised, and that no one kicked in all the doors out of spite (I assume this kind of thing is a possibility when a rental house is sold, since the renters are getting kicked out and may be unhappy about the situation). So, we scheduled the walk-through date, and I invited my two contractors. I was fortunate with floors and paint, as I had contractors I'd worked with before, and liked: Reliable Floor Coverings in Edmonds, and Juan Hernandez.

The walk-through date came, and a third agent (my agents were out of town, I think it may have been Spring Break for their kids) and I walked through the house. The staging stuff was all over the place. Somehow, the wires had gotten crossed. I couldn't inspect the house when there were tables and rugs and stacks of framed art piled against the walls, and I wanted to see the house after the stagers had gotten everything out. Still, the contractors were called, so we waited until they both had their chance to walk through and we could talk through the work to be done.

The process ground forward, and with interior floors and paint covered, I tried to figure out the garage floor situation. There seem to be a zillion nearly-identically-named garage floor companies in Seattle with a variety of nearly-identical floor coverings they specialize in. I ended up settling on a company that would put down a polyurea base coat, grey vinyl chips, and a polyaspartic top coat for a mere $6 per square foot.

Anyway, on April 24th, I took possession of the house, and I had a mini party with a few friends where we sat on the floor in the dining room with paper towels and ate delivery pizza. It was glorious, of course, but only marked the beginning of the next phase.

Enter, the Contractors

Juan was able to swoop in and get started on the paint right away. He started on Monday the 29th, and was done before the end of the week, having done a great job. I had imagined paint might take a while, so that was very gratifying.

Flooring was a different question, and the bathroom tile didn't start until the following week, though it wrapped up quickly once started.

The initial carpet removal for the bedroom was actually done very quickly, only a few days after possession, but we ran into a snag. My hope was that we'd be able to save the 1921 era vertical-grain fir flooring under the carpet (I'd dramatically slashed a big gash in the carpet with my friends over, so we could see what the fir looked like -- ah, the liberties you can take when you own the place). It looked to me like it might be possible, though my contact at Reliable was pretty sure it was a lost cause. It was covered in paint from what I could see, but looked good other than that.

Sure enough, once the Reliable guy came out to remove all the carpet, it wasn't really salvageable: the room had clearly once been two rooms, and a wall had been removed to make it one big room. Where the wall had been, some previous owner had had to fill in the missing flooring, so they jammed some plywood in to make it all level when they installed carpet. Patching that seemed pretty unlikely, so I reluctantly made the call to replace it with new oak. Of course the price more than doubled compared to the initial refinish-the-fir estimate. Sigh.

The other thing that happened with the new oak plan is that oak had to be acquired, and allowed to acclimatize to the house for most of a week. By the time all was said and done, the oak installation was scheduled for May 15, and the person scheduling it with me said it would last from that Wednesday through the following Monday to get all three coats of the finish down. That would put it out to about Wednesday the 22nd before I could be in the house again -- Swedish finish is awesome in a lot of ways, but it's viciously toxic-smelling while it's curing, so I wanted to give it a day or two to air out.

Then came the question of movers. A friend had turned me on to what sounded like an awesome deal: union stagehands doing work on the side as movers. I was in for that action, for sure. Scheduling with them took longer than I expected when my first email went to the wrong gmail address (and of course whoever got it didn't reply to tell me they had no idea what I was talking about), and I didn't follow up until a week later to see why I hadn't heard anything yet. Then was the interminable and increasingly anxiety-producing wait to schedule the exact date -- mostly because by the time the moving date was scheduled, it was less than a week away, and I was having visions of having to wait another month or more to schedule with a different company, in June, the very height of the everyone's-moving-now season.

I popped my head into the house on the Tuesday after what I had supposed would be the final day of floor finishing (wearing a respirator, because I enjoy having brain cells). It was with some consternation that I spotted a couple of dead flies on the floor that had been there on Saturday as well, indicating that the putative third coat had not happened. I tried a tentative breath without the respirator, and sure enough, no evil smell (or at least not enough to fuss about). I called the flooring place to figure out what was going on -- it turns out that either I misunderstood or the scheduler misunderstood, and we had reserved time for one more coat of finish than I'd been quoted. Most frustrating about that was it left me thinking I couldn't really be in the house until Wednesday, when in fact the previous Sunday was fine. I could have been moving then, dammit!

My agents had offered to bring in a cleaner as a closing gift, and that was the final thing to schedule before I could start moving in fa realz. I'm glad I waited, they did an amazing job, even cleaning inside kitchen cabinets and drawers, and cleaning up all the masses of cobwebs in the basement.

Then, finally, on Thursday last, I was free to actually move into the house I'd bought so very long ago. I know I brought on the delays myself, and they were totally worth it (the paint and floors look great!) but I was very ready to be moving in already!

Fortunately, the move date was Saturday on the long Memorial Day weekend (this year I will be remembering our nation's fallen soldiers by unpacking boxes and arbitrarily deciding this cabinet will be the snacks cabinet and that one will hold the plates), and went well. We got most of the stuff out of storage, and most importantly got all the things which absolutely require two people to move. Naturally it started pouring rain for our second trip from the storage unit. I greatly enjoyed working with my stagehand movers. We are cut from the same cloth, which made working together very natural.

I am even now sitting in my new bedroom, surrounded by boxes and arbitrarily-placed furniture while listening to music from an Android tablet, but at least I'm here. As of 10:15 tonight the final curtain rail is hung in the bedroom, so I can actually maybe sleep in tomorrow a tiny bit. The important stuff is available: a bed for sleeping, a shower so I don't feel completely grimy, and a somewhat assembled kitchen to prepare bachelor-chow (Now With 10% Fewer Rat Parts!™).

The contractor shuffle is done, and now it's up to me to get it all done. I've only been to the store five or six times in the last two days. Not bad.

Posted at 23:54 permanent link category: /misc


Tue, 14 May 2019

The Need for Speed

Norbert the Champ has been ailing a bit in the last few months. I've been flying every few weeks, as the weather allows, occasionally letting a whole month pass between flying dates. The problem is, when the engine sits like that for long periods, it gives condensed water a chance to attack the innards and start creating rust.

The accepted remedy for this problem is to fly more often (how convenient!). The idea is that by flying, you warm up the oil, and encourage the water to evaporate out, as well as getting a fresh coat of oil in all the places it's supposed to be. Ideally, you want the oil to be 180-200°F for at least half an hour to get the water out.

Fortunately, I haven't noticed Norbert's ailment in the sense of feeling like anything's wrong as we fly. Rather, I've been noticing that the crankcase breather tube is drooling a bit of oil/water mixture after flights. I'll come back a week or so later, and there's a 2" pool of mocha-colored oil-water emulsion sitting under the engine, almost exactly like it had a little potty training accident.

The plane is equipped with an air-oil separator, which is a little thing the size of a beer can which is supposed to condense the oil out of the crankcase breather tube, and let it drain back to the oil tank, rather than sending it out over the belly of the plane in flight. It seems to work pretty well, but this new pool of oil was worrying.

Did it mean the separator needs to be cleaned? Did it indicate some other problem inside the engine? The oil on the dipstick came out looking like oil (good) and not like mocha foam (which would be bad), so I wasn't sure.

Finally this last weekend, I got a chance to chat with the local mechanic about it, and his recommendation was to go fly the plane a bit to warm up the engine, then do a compression test. This would confirm whether any of the cylinders were leaking more than they should. Previous compression tests (we do one at least every year) have been good, but this one showed that the #4 cylinder was down a little bit. Apparently the ideal number is 79 out of 80, with a full 80/80 indicating a problem, and anything down to about 40/80 being in the acceptable range (this is hard for my perfection-oriented brain to comprehend, but apparently is true).

After the compression test, the A&P mechanic said, "Frankly, what I'd recommend is that you go out and fly for a while at higher power, like a high-power cruise. That'll probably improve this, though even 72/80 is pretty good." This actually aligned well with my thoughts on boiling the water out of the oil, so I set out to see what I could do.

Norbert and I launched into the warm May day (it was over 80°F that day), and I set out to fly it like I basically never do.

The first order of business was not to climb too high. Normally I'm in the "altitude is insurance" game: the higher you are, the more gliding distance you have if anything goes wrong with the engine. However, the air is thicker and hotter down low, so I mentally plotted a course over a set of flat fields through the Snoqualmie Valley.

The next thing was to push the engine faster than normal. I've settled on a fuel-sipping 2200 RPM cruise (2500 is the maximum, or nominally 100% power), which probably represents around 60-65% power. I've been burning about 5.5 gallons per hour at this setting, which seems like a nice level. I have no idea how much fuel we'd actually burn at higher power, but presumably around 8-10 GPH, which is a lot for a 90 HP engine on a plane like this.

So I launched from Harvey and aimed myself southeastwards. It was interesting to see what happened.

I set myself up for about 1700 feet of altitude, which puts me safely over the legal limit, but not so high that I was losing much heat from the ground-level air. I pushed the power until it was just shy of the 2500 RPM redline limit. The plane made a constant shimmy and judder feeling, very light, but enough to communicate to me that it wasn't happy. The louder engine noise combined with increased wind noise to give a sonic edge to the plane's discomfort. We ended up cruising around 105-110 MPH, vs. my normal 85 MPH at 2200 RPM. Gratifyingly, the oil temperature kept rising, finally stabilizing just below the 200°F mark -- I haven't seen over 150° since last summer. Maybe I have been under-working the engine.

I flew most of the way to North Bend, then turned around over Carnation and flew back, circling once over a friend's house, and then looped back around to Harvey Field. I briefly lowered the engine back down to 2200 RPM and let it settle into its happier cruise speed. It was remarkable how much more comfortable the plane felt. Then it was back up to nearly 2500 for the return to Harvey, and an uneventful landing.

In all, just shy of an hour's flight time, almost all of it spent at just shy of full power. Out of curiosity, I checked the fuel left in the tanks -- I'd taken off with around 21 gallons -- and found there were about 14 left. 7 GPH for nearly full throttle. I had expected more, and would probably plan on at least 8 if for any reason I had to fly for any distance at full throttle; part of my hour's flying time included taxiing on the ground. My fuel dipstick measurement technique is fairly crude, and will never be more accurate than within about a gallon or two (gas cans always seem come in frustrating "gallon plus 3 ounces" sizes to accomodate people mixing 2-stroke fuel, making accurate measurement very difficult).

I was able to visit the plane Tuesday night after the flight on Saturday, and found a small puddle of discarded oil, fortunately not as mocha-colored. There is a distinct trace of oil running down the belly, but it's coming from somewhere in the engine compartment rather than from the breather tube.

A very interesting experiment in Going Fast with my pal Norbert. My key takeaway is that I should probably be running the engine harder for its own good health. The slightly increased fuel burn is a fair trade-off for not having to overhaul the engine (a $25,000 proposition) early.

Posted at 22:21 permanent link category: /aviation


Thu, 09 May 2019

The Great House Kerfuffle

As 2018 descended from summer into fall, it became apparent that the living arrangement my partner and I had wasn't working any more. As winter started up, it became clear that it was working poorly enough that I should probably start packing my stuff. It was unfortunate, but these things happen, and better to part on good terms, which we did.

I had built myself a neat little shop at Hogsmeade Hollow (our shared house), though it was a bit on the small side due to lack of real-estate. It had many electrical outlets (one every 3 feet or so), it had lots of light, with skylights and more LED shop lights than you might have thought reasonable. It had a very cool set of swing-out doors, so there was no overhead track, and there was a smaller wicket door in one of the bigger doors. That's where I was building my biplane.

Of course, when it came time to pack up and move out so we could sell the house, the biplane project had to get packed up as well. Even if the new owner could be persuaded to let me keep working there, I wouldn't want to, since it would invariably be a trek to get there from wherever I ended up living -- no way could I afford to live as close in as Hogsmeade Hollow on my own.

So, it all went into storage, and I moved in with some friends who were willing to let me rent their spare room for a few months while I looked for a new house. Not quite living out of a suitcase, but not that far from it, either.

Then commenced the house hunt. For weeks and weeks and weeks I looked at houses. Starting in January, before I'd even moved out yet (which wouldn't be until the end of February), I was looking at houses. There were some... interesting ones, but nothing that really grabbed me.

I saw houses that were in a great location, but too expensive and with no way to have a shop (a full-stop requirement so I could continue building the biplane). I saw houses that had a perfect shop, but the house itself was so dreary that I could never imagine actually wanting to live there. I saw one house near Aurora that had an amazing dream shop that was also plainly illegal and unpermitted, in the zone of rapacious condo developers who would turn in the owner of such a house in roughly 1.3 heartbeats. I saw houses that were a fine combination of house and shop, but far away from where I wanted to be. I saw one house that had clearly been slowly expanded over the decades by an enterprising owner who really didn't know how to design living spaces, so it was a warren of little four foot tall rooms and improbable doors. I would have had anxiety dreams of finding new, weird little rooms for the rest of my life if I'd lived there.

Finally, as spring started to spring, I started to see more promising houses. I had moved out of Hogsmeade Hollow, and was living with my friends, with a 10x25' storage unit packed in a towering cliff to the edge of the door, and I found a house that was genuinely interesting.

It was built in the 90s, and was grey, situated on an odd little square lot deep in the middle of a block, three houses from the road on a private driveway near but not too near Lake City Way. It was the home of some famous session musician, who'd played with the Beatles, and had framed LP covers all over the walls. It had a pretty large 2-car attached garage, and a kind of funky four-bedroom-and-living-room situation upstairs. It was, attractively, about a 5 minute walk from Fred Meyer and some unexpectedly fast buses to downtown.

But. When I thought about it, my approach to this house was, "Well, it checks many of the important boxes on my checklist of Things I Gotta Have in my Next House." It was, simply, acceptable. The price was decent. It had enough rooms for what I wanted to do. It had an acceptable but not great shop space, with potential to be pretty good (but not great). It was, in my mind, a kind of acceptable grey, much like the color of the siding. I totally could have made it work.

That, however, is not a great way to approach a ¾ million dollar investment that should keep me happy for the next 20+ years.

I dithered. I talked to friends and parents and my real estate agents for hours and hours trying to work out if this was a good idea or not. I simply couldn't decide, since my emotional reaction was absent, and my logical reaction was 95% in favor of the place. A noticeable part of me knew it was the wrong choice, but the months of searching had worn me down, and it was ever so tempting to just get it over with, even if it wasn't the perfect house.

Still dithering, and still poring over real-estate listing websites like my life depended on it, I marked out a few more houses that looked like they might be promising, but almost certainly would let me down somehow in person. Agent in tow, we went to look at them, stopping first at the grey house again to see what I thought of it on second inspection. No different, as it happened.

The second house on the list for that Saturday trip was in North Seattle, about 10 blocks north of my previous house on Dayton -- that had been my starter-house, and I'd planned to be there for around 5 years, but ended up staying for 15. This North Seattle house was listed as being a bit over 3000 square feet, and over my maximum price, so I figured it would be a fun lark then we'd move on. 3000 square feet is far too big for just me, though the photos looked pretty good.

I'd taken to bringing along a GoPro style camera that I wore on a forehead harness, so I could record what I was seeing as I walked through all these different houses. They started to blend together something fierce; having a recording of what I'd seen was great for keeping them apart in my head, and occasionally helped me understand some factor I hadn't been paying attention to the first time through. I only made it the length of this North Seattle house before you can clearly hear me say on the video, "You know, I think this is The One."

This house (which I am provisionally calling Brinkley Manor in my head, after the country house of Tom and Dahlia Travers, Bertie's sole good aunt in the P.G. Wodehouse stories of Bertie and Jeeves, which country house is called Brinkley Court -- I think my grandfather would find this funny, if he were around to hear my Wodehouse reference) has a wide front porch with a swinging bench on one side. The front windows contain cut-glass tulips in lead framing, an elegant touch you don't find on modern houses. It has a large living room with a fireplace insert, an unexpectedly open dining room, and a spacious though outdated kitchen with a generous eating nook off the back end. It has four bedrooms, the first of which is on the main floor, and is an odd oversized, elongated shape. Upstairs are three bedrooms and a full second bathroom. And in the back yard, sitting unpretentiously and awaiting my attention, is an oversize 2-car detached garage which is (just barely) wide enough to accept a fully-rigged Marquart Charger biplane, and long enough to (comfortably) accept a fully-rigged Marquart Charger biplane. This house, this provisional Brinkley Manor, has a full basement in which I can stand comfortably upright nearly everywhere. It smells of wooden floors and old-house, an aroma which I find nearly irresistable.

It is, in short, The One.

Of course, it has downsides. The price is the big one -- the listing price was nearly twenty thousand over my maximum price, and had been dropped repeatedly since it was first listed, a discouraging sign. It is possessed of a surprisingly large lot, most of which is covered by lawn, which requires far more care and maintenance than I want to put in. Every single appliance in the place is at least 25 years old, and all appear to be near the end of their lives. It needs a surprising amount of maintenance on the brickwork, which has been let go for too long. It is, frankly, several bedrooms too big for one guy and his biplane project.

However, it only took me about 20 minutes of thinking to realize that I wanted to put an offer in. We called the seller's agent and got the story that there was a previous buyer, but they were first-time buyers and had been utterly freaked out by some heavily-charred floor joists in the basement (properly reinforced and stronger than when the house had been built), presumably in addition to the looming dollar-signs over every appliance and some of the less well-maintained aspects of the house. The price had dropped more than fifty thousand dollars since it first listed, and it had gone pending, then come back on the market. Both of these things are enormous black eyes in the current Seattle housing market. It went on the market in Feburary, in the middle of a giant snowstorm which kept pretty much every potential buyer off the streets and out of open houses, and had been on the market for over a month (another black eye).

All of this added up to the idea that I could offer less than asking price, and be reasonably certain it would be accepted. We actually got Hogsmeade Hollow under similar conditions, with a previous buyer who backed out on the inspection, doing the house a noticeable injury in the market.

We had the previous buyers' inspection report for this Brinkley Manor, and I pored over it carefully: it's a 100 year old house, and had a modest set of 100 year old house problems. Plus it's got a bunch of old appliances that will need to be replaced soon. That's what's wrong with it. All acceptable to me, so we prepared a no-inspection-required offer and submitted it on a Thursday evening. It was countered the next day, within 12 hours: the price was accepted, but the seller (we suspect actually the seller's agent, not the seller himself) required a zero-day inspection period for the title documents.

This still seems a little petty to me, but they stuck to it tenaciously. It seemed to be a reaction to the previous buyers backing out -- they wanted to give me as few outs as possible. The practical effect was that I needed to carefully review the title documents (which should have all been present and available) before saying yes. Presuming I didn't find anything objectionable, we could proceed.

There followed the most stressful weekend I've spent in quite a while. Of course I tried to look over the title documents on Friday evening, and of course one of them was missing. It appeared in the title report as a link, and when I clicked on the link, the resulting page said, "This document has not yet been received from the county." The title report was dated August, 2018, about 6 months beforehand. That document was not going to be arriving from the county. The missing document was the Conditions, Covenants and Restrictions document, arguably the most likely place for Unacceptable Hijinks to appear, so I was very reluctant to just wave my hands and say, "Yeah man, no worries."

But, naturally, the title company was closed for the weekend. My agent pulled some strings, and suddenly in the middle of Saturday, a title report appeared in my inbox for a neighboring lot. Weirdly, the recording number for the document I wanted to see was identical to the one that was missing from the other report. I read it over, and found nothing objectionable (but definitely hilarious: 1. no house worth less than $2000 may be erected on the lot, 2. no barn or other nuisance will be permitted on the lot -- apparently people were moving far from downtown to make little farms in 1921). But it wasn't for my lot, so it didn't really help. There was some back-and-forth about the identical recording number, but that was inconclusive.

I put together some moderately legalistic language for a counter-offer, which basically said, "I'm 100% into this house, but I need 6 hours after receiving the missing title document to make sure it doesn't require me to host a boarding house for evil clowns or something," and we floated it past the seller's agent. No dice.

Then, equally suddenly, on Sunday morning, I received a new title report, dated February 2019, and, hallelujah, it had a working link for the correct CC&R document. Same restrictions. No problem. No clowns. A quick docu-sign session, and suddenly we're under contract. The open house that Sunday was still held, but we presume that anyone who tried to make an offer was told the house was already under contract.

Everything from then on flowed in a pleasantly clockwork-like manner. The loan came through in record time (only about a week), and a few weeks later, I was signing a giant stack of papers asserting that I'd be paying a lot more in rent every month, but I'd have a pretty sweet place to lay my head each night.

On April 24th, 2019, I ditched work early and went to the real-estate office to pick up an improbably bulky envelope full of keys, and take possession of my new house. If I'm very diligent and pay my bills every month, it'll finally be all mine in 2049.


The putative Brinkley Manor; click for gallery

Posted at 00:21 permanent link category: /misc


Sun, 21 Apr 2019

Flying for Passport Stamps

The Washington State Department of Transportation and a bunch of aviation organizations just released the Fly Washington passport program. Basically, it's a program where you get a free "passport" booklet which contains a bunch of blank spots organized by region of the state, and your job is to fly to different airports and fill out the passport. Apparently there's some kind of prize at the end if you fulfill a set of requirements.

The goal of the program is to encourage aviation, and particularly to drive traffic to smaller airports that have been suffering from lack of use in the last decade or two.

I'm here to tell you, I love this kind of thing. I always envied people who had passports full of visa stamps; there's just something so satisfying about all those stamps from all those places. It's not even the places that appeal to me, just the sheer collector-impulse OCD satisfaction of pages covered in stamps. So I fell for the Washington aviation version hook, line and sinker.

Despite what it says on the official page, it appears that most airport offices have at least a handful of passport booklets available. You don't have to go exclusively to the four official places to pick one up. I was able to get one at the Harvey Field FBO office, and they had a stack of at least ten more ready to give away. At least here at the start of the program, it's worth asking at your local airport.


Norbert at the Darrington Airport (1S2)

This weekend was my official entre into the passport stamp game. I managed to hit five different airports over two days -- yesterday I flew up to Lynden to visit a friend, and today I took the afternoon to specifically go out and collect some stamps, eventually stopping at Arlington, Darrington, Paine Field, and Harvey Field. I expect to have more days like this over the summer, where I just go flying for the day and hit new airports I haven't visited recently, simply to collect the stamp.

The thing is, from what I can tell, pilots will grab at nearly any excuse to go flying. It acts nearly like an addiction. "Gotta go collect some stamps" is a ready-made excuse, and seems to me like an excellent way to get a bunch of pilots into the air and visiting airports far and wide across the state.

On today's flight, I started out at Harvey as usual, and grabbed the stamp from the office, where it's temporarily being kept until they set up an external station for it. Then it was off to Arlington for my next stamp -- Lynden was collected yesterday. Arlington was interesting, because the wind changed direction as I was fuelling up, then Norbert's carb heat seemed to malfunction at the run-up check. I pulled back around to a taxiway, shut down, and did a quick visual check -- everything looked right, and on the next run-up it worked like it should. These little Continentals apparently ice up at the slightest provocation, so a malfunctioning carb heat system is a big deal.

From Arlington, I had to ponder where I wanted to go next. Norbert is still limited by a lack of blinkenlights, which keeps it from being legal for night flight, so I had to be back to Harvey before the sun set. That ruled out any longer flights, but as I was looking at the chart, I realized that Darrington was only about 25 nm away, and I'd never been there before. That seemed like an ideal destination, so I launched and turned northeast from Arlington.

The Darrington airport is a very small strip set near downtown Darrington -- Darrington is a town of about 1400 people, so "downtown" is a relative description. Nevertheless, the airstrip is right in the middle of town. I was interested to see runway lights and a beacon: I had flown (in a different plane) out to the Concrete airport a few years ago hoping to watch a meteor shower from a very dark place, but Concrete didn't have runway lights. Darrington isn't quite as dark, but the ability to actually land at night overcomes that downside to some extent.

The wind was blowing pretty strongly from the west, so I set up for runway 28. I actually overestimated the amount of wind the first time around, and wound up too high to land, so I went around and tried again rather than try to salvage an obviously flawed landing approach. Once I got down, I parked the plane next to a helicopter with a massive boom strapped to the skids, which looked like it hooked up to some kind of geological sensor box. The stamp at Darrington is located in a "small box on the beige hangar" -- with the aid of the photo on the passport website, I realized it was what looked like a discarded electrical junction box. I gathered my stamp and took a few photos. I found Darrington to be a surprisingly delightful little airstrip.

The flight back was not as daunting as I'd feared (I was expecting the headwind coming up the valley to really slow me down, but it wasn't bad), and I realized that it was only 7:20, and I had ages until sunset (8:03 pm), so why not pack Paine Field into the flight? I entered my best powered-descent mode, hitting 115 MPH (normal cruise is about 85, so this is screaming for Norbert) as I made tracks for Paine's traffic pattern.

Once on the ground, the Paine ground controller didn't know about the passport stamp, so I stealthlily looked it up while doing a very slow taxi. I called the ground controller back, and after a few minutes of mutual confusion, they got me directed to the right spot, right next to Regal Air. I leapt out of the plane, ran into the flight planning space, stamped my passport, and dashed out again. Norbert was swung 180° and shuddered to life again -- that sun seemed to be accelerating toward the horizon as a cloud bank suddenly hid it from view, and the moment of sunset is my official cutoff.

Fortunately, there was no waiting to get to the runway, and I was off the ground having only spent about 10 minutes between landing and takeoff -- that's definitely a record for me. I managed to touch down at Harvey with nearly 5 minutes to spare, and relaxed with a celebratory snack as I watched the sky fade from blue to pink to purple over Norbert's nose. I had spent a mere 14 minutes between starting the engine at Paine and shutting it down at Harvey.

Flying continues to be a surprisingly potent source of happiness for me. It finally took finding my own airplane to really get into the groove of things, but I'm glad I did. Now I just have to plan out the next few batches of passport stamps I need to go for...

Posted at 22:48 permanent link category: /aviation


Sat, 23 Mar 2019

Crosswinds and Turning Stalls


Image by Chris Kennedy, used under CC BY-NA 2.0 license

I found myself with some free time a couple days ago, and decided to take Norbert the Champ up. There was an occluded front due in the afternoon, so I had to abandon my original plan to fly over to Port Townsend (0S9) for a late lunch. Instead, I decided to do some pattern work and possibly some turning-stall work in the practice area. I wanted to stay close to the field so any nasty weather that turned up wouldn't catch me away from home.

According to the new weather robot at Harvey Field (S43), the wind was blowing about 180-190°, and between 10 and 15 knots in gusts. The closest runway is 15L, so there was a bit of crosswind, but nothing terrible. The gusts made things more interesting, but fine practice for me -- I rarely get to take off and land with crosswinds and need all the practice I can get.

One of the members of my EAA chapter has been developing a pretty cool program aimed at experimental (homebuilt) aircraft, to determine and then correct low-speed stall characteristics. Specifically, he's worried about the base-to-final turn, which is the closest to the ground most pilots will ever turn, and thus the one most fraught with danger should anything go wrong. He recently lost a friend to a likely stall-spin accident on a base-to-final turn, so his idea has received fresh momentum.

Something he mentioned recently was that most pilots haven't explored their aircrafts' stall characteristics except the most basic straight-ahead power-on and power-off stalls. Stalls while turning can be very exciting, easily leading to a spin -- a condition which may be unrecoverable at low altitude, and a prolific killer of pilots in the beginning years of aviation. I realized that not only did I not know my plane's behavior in this condition, I'd never done a single turning stall in my entire flying career.

The setup for these stalls is exactly the same as normal stall practice, except the plane is turning. Add at least another thousand feed of altitude compared to normal stall practice, just in case. A spin can develop very quickly, and the extra space gives you a bit more breathing room to recover if it surprises you. It would be best to have experience recovering from spins and recognizing incipient spins before trying this yourself, but read this handy article on spin recovery at a bare minimum. I spent several hours doing spin recovery training with a CFI a few years ago, which makes me barely competent, but I felt safe enough to give turning stalls a try.

The first thing I tried was power-off turning stalls. I figured, correctly, that with less energy involved, things would be a bit calmer. So I set up for my normal descent to landing -- carb heat on, power to idle, and enter a 20-30° bank to turn from downwind to base. Since I didn't know exactly when the stall might happen, I put myself into a constant rate turn, kept the ball centered with the rudder, and pulled back on the stick. With the hand grip buried in my belly (I really need to get rid of that thing; the belly, not the handgrip) and maintaining a nearly 45° bank angle, the plane simply refused to stall. Just to eliminate the possibility that the 7EC Champ is more resistant to turning stalls to the left than to the right, I climbed back up to 4000 feet and tried again, this time circling to the right. Nope, no stall.

Surprised, I climbed back up to 4000 (the Champ didn't seem to be stalled, but it was definitely going down quickly, losing 700 feet in what felt like maybe 45 seconds) to try power-on turning stalls.

This time, I set up for a fairly unrealistic 45° bank coordinated turn at full power, and held the stick full back until I got a definite stall break. To my complete surprise, with the stall, the plane rolled sharply away from the direction of the turn, trying to roll into an opposite-direction turn and possibly stall/spin (I stopped it before it could develop). I tried in the other direction: same thing. Weird.

I haven't yet figured out the aerodynamics of what might be happening with the power-on turning stall, but I was interested to see that it also seems to happen with the 7AC Champ model in X-Plane. My understanding was that X-Plane treats stalls in a somewhat unrealistic manner, since the aerodynamics get pretty tricky around stalls, and it's hard to simulate them properly. It's cool that the simulator mimics real life in this situation.

My EAA member's idea (I'm not naming him because the program isn't official, and I'm not following it, just inspired by the discussion) with his base-to-final stall/spin reduction, as I mentioned earlier, is that pilots of homebuilt aircraft should explore their planes' stall characteristics, including in a turn, like I did. Once it's determined whether the plane wants to drop a wing in a stall (leading to a spin), apply appropriate anti-stall modifications to the wing, such as vortex generators, stall strips, etc. to correct the behavior. This should lead to a safer and more predictable plane. It's a great idea, and I'm glad he's working on it.

I'm equally glad that I tried out a couple of turning stalls to see what would happen in my plane. The results were very surprising to me, both the fact that the plane didn't want to stall in a turn with the power at idle, and the manner in which it stalled with power on. I may spend some time exploring the power-on stall a bit more, to see if I can figure out what's going on with the airflow that causes the plane to flip around like it does. I'll continue flying well away from the potential danger zones of the stall. I'm glad to learn another bit of knowledge about how my plane behaves.

Posted at 23:00 permanent link category: /aviation


Wed, 26 Dec 2018

Building a Biplane: The Data Edition

Just a short take for this one: I've finally put together a page to display my live buildlog. One of my first tasks for myself before I started building my airplane was to code up a simple system to record my activities in a database. One of the big reasons I wanted to do that was so that I could display that log of activity on a web page. I finally found some free time, and put together that web page last week:

My Marquart Charger Buildlog

It's got data (with more to come, I just haven't had time to code it up yet), and it's got photos. Enjoy!

Posted at 10:58 permanent link category: /charger


Fri, 07 Dec 2018

Building a Biplane: In Which Mistakes are Made

I've been warned repeatedly that I was going to make a bunch of parts, then realize I'd have to completely re-make them due to some small error or flaw I built in without realizing it. So, in a way, I'm better off than I could have been.

Having now completed all 36 drag strips (why 36 when I needed 32? Let's charitably say I was building in my 10% extra and not just mis-remembering), I finally sat down to figure out what was the deal with these drag wires everyone else uses. Good timing, right?

So, I worked out the math. The drag strips are .063" thick and 1/2" wide. The total length of drag strip material is 916", if you add all the plans-specified lengths together. Add another 32" for the 1" doublers that go on the flat end of each strip, another 16" for the 1/2" of length after the flat-end hole, and another 51.2" for the 1.6" length each strip is folded over. This amounts to 1015.2" of strip length. With a cross-section of .0315 square inches, this adds up to about 31.98 cubic inches of 4130. It takes about 3.6 cubic inches of 4130 to make a pound, so the final weight of all this metal is:

8.88 pounds

4130 steel has an annealed yield strength (the strength at which deformations like stretch or bend become a permanent part of the metal) of 52,200 PSI. So one square inch of 4130 will lift 52,200 lbs before it will yield. .0315 square inches of 4130 will lift 1644 lbs if the metal is in the annealed heat-treat condition. This annealed condition is important because it's the weakest state of the metal, and after welding, you can't count on the heat treatment state of the metal around the weld. For normalized 4130, the yield strength is 63,100 PSI.

The turnbuckles, at .06 lbs each, add another 1.92 lbs of weight. We will ignore the weight of the pins, since the alternative wire construction will also use pins (though they'll be shorter, and so will contribute to any weight savings). The turnbuckles are rated for 1600 lbs as their "strength" (I'm not sure if that's working load or yield load or breaking load, but I'll guess it's either yield or working load), so they match nicely with the 1644 lb strength of the drag strips.

Total weight is now: 10.8 pounds for the drag strips. Not bad.

But what about wires?

This is where things got real for me. I checked, and realized that although a 3/16" wire has a smaller cross-section than a drag strip (.0276 in2 instead of .0315 in2), the wires are guaranteed to be normalized. You don't have to weld them, so you don't mess up the heat treatment. This means you get to use the higher 63,100 PSI number, and a 3/16" 4130 wire has a yield strength of 1741 lbs. So... it's stronger and weighs less? What's the downside?


AN665-21R clevis fork rod ends (like you didn't know that already)

There really isn't one. The wires by themselves weigh 8.12 lbs (916" length plus 144" to account for the now-missing turnbuckles, for a total length of 1060"; making 29.26 in3 of steel). You have to add AN665-21 clevis fork rod ends and locknuts, which add up to 1.16 lbs for a total weight of:

9.28 lbs for drag wires.

Hmm. Compared to 10.8, 9.28 sounds pretty good. Saving a pound and a half is nothing to sneeze at -- I've heard tales of people substituting titanium fasteners on a plane for a total savings of less than a pound, at the expense of several thousand dollars. Here, I can do it by returning a thousand dollars worth of turnbuckles and buying $800 worth of rod ends and $200 worth of steel rod. So, I spend the exact same amount of money and save 1.5 lbs? Sign me up!

Now, it would have been really awesome if I'd figured all this out before spending a bunch of hours making drag strips. So, if you're building a Charger, this is my gift to you. Go figure out drag wires rather than wasting a bunch of time on heavier strips. Fortunately, I had a good time with making the strips, and I don't consider it time wasted. I got to meet a local Charger owner to have the strips cut, and learned about fabricating an interesting part. And now I get to play with threading a bunch of 4130 rod and RMA-ing a small army of turnbuckles.

Posted at 21:44 permanent link category: /charger


Mon, 03 Dec 2018

Building a Biplane: The Many Steps to Actually Make a Part

I've been impressed by the seemingly countless steps necessary to actually make a part for this biplane build. I'm currently in the middle of making the drag and anti-drag strips, which will go inside the wings as crossing "wires" to keep the wing structure from racking forward and aft.

At first glance, the drag strip idea makes a lot of sense -- no special tooling required, sheet metal is widely available (and probably more available or cheaper in the late 1960s than 4130 wire of the appropriate size), it's easy to cut on a sufficiently beefy shear, etc. However, on reflection and having accomplished 90% of the construction of the strips, I think I would have been happier buying wires.

Here's what it takes to make a batch of 36 drag strips:

  1. Acquire sheet metal. $80 at Online Metals for a 2x3' sheet of .063" normalized 4130. This was by far the simplest part of the process.

  2. Find someone with a big enough shear to tackle 1/16" 4130. I managed to find someone through the Biplane Forum who offered to do it for free at his shop. We cut my sheet into about 40 1/2" by 36" strips.

  3. Polish the edges of the cut strips. I finally figured out that I could hit multiple strips if I was careful by using the belt sander that has served me so well making ribs. This process alone took over 2 hours between finding the right procedure and actually doing it. I started out with draw filing individual strips clamped in the vise, which doesn't count the 2+ hours I spent making perfectly smooth vise jaw covers. Such a simple operation that took so much time and head-scratching.

  4. Bend the teardrop end of the drag strip (see the above picture). 4130 is no slouch when it comes to the strength department, and I wanted to get these bends perfect the first time. The solution I eventually came up with was to build a bending jig out of beefy 1/4" thick angle iron and 1/4" plate (7.3 hours, not counting driving around hardware stores for a couple hours, looking for 1/4" angle iron). This can be used in the 12-ton el-cheapo hydraulic press I got back in my engine rebuilding days to get the strip most of the way bent, then it's off to the vise with a hunk of 1/4" round to close the end of the loop, but keep the teardrop open.

  5. Weld the edges of the loop's tail. For all my initial fears of welding, this was among the simplest operations in this process. It still took 3 hours to weld all 36 of them.

  6. Cut the slot into the teardrop. This process was the subject of much heartache for me. My first idea was to use my milling machine with a very tiny endmill to cut the slot before the strip was bent. This worked, but was very slow, and ran a substantial risk of breaking the cutter, for it was ever so wee. Then I had the idea to use a slitting saw in the mill once the loop had been bent. Much better, but I discovered that after welding, the slot would expand a bit, and the plans are very particular that the slot should be a particular size. So I thought it better to weld first, then cut the slot to eliminate welding as a possible source of error. I welded up the first 17 strips, and tried to cut the slot in one of them, only to be horrified to find that welding modified the strength of the metal such that the saw (which had worked perfectly before welding) suddenly sounded like it was about to explode. Finally someone on the forum suggested using an abrasive cutoff wheel, which worked well, and was the method I finally used to cut the rest of the strips. I spent nearly 5 hours just figuring out how to cut slots and then slotting all the strips. I'm glad I didn't have to use a hacksaw and file to do the job, as someone suggested when I asked how Ed might have expected the average homebuilder to do it.

  7. Clean up the welding scale. I started out by hitting the strips with sandpaper to clean up the scale, but it didn't do a very good job. I finally switched to a wire brush and had much better success. I also destroyed two partially-used wire brushes in the process. If I have to do any more of that, I'm getting the wire wheel set up on my bench grinder again. I need to do that anyway, as long as I'm welding parts.

That's the process so far. I'm not done yet, but that's as far as I'm taking it until the wings are built, and I can see exactly how long each strip needs to be.

By contrast, the steps necessary to deal with wires would be:

  1. Buy wire. This requires an order from Aircraft Spruce, and costs more than the sheet metal ($128 + shipping vs. $80 for sheet metal).

  2. Cut wire to length. Hacksaw and file to clean up the cut.

  3. Thread ends. Time-consuming, and requires a left-hand threading die for one end, but a well-denfined problem with a well-defined solution.

That's it. If I had it to do over again, the extra $50 would be 100% worth it. I think the turnbuckle situation would be a bit cheaper too, by at least half. If you find yourself building a Marquart Charger, may I humbly suggest that you don't follow the masochistic "Do it exactly per plans" path that I have, at least for this particular situation.

For your edification and edumacation, I also filmed much of the process and turned it into this moderately interesting video:

Posted at 23:06 permanent link category: /charger


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