Guppy trailer, part 5: 1000-mile test



On July 4, we drove to Ashland, OR and saw Misner & Smith in concert. It was 107 degrees in the Sacramento Valley during our drive, so we had the air conditioner on most of the way. We found that the AC slowed us down far more than the trailer. Aside from an occasional chunka-chunk shaking of the trailer-hitch, the trailer’s effect on the car was barely noticeable. A good sign! In the image above you can see now the Guppy is relatively large compared to our golf, but tiny compared to a standard American camper.


Ashland is quite beautiful; I recommend it. Dragonflies.130705_0642_TrailerAtApt

Our first night on the road, we camped behind an apartment building. Not so romantic, but realistic: the Guppy is designed so that we can camp wherever we park. Here you can see the unfinished back end; we won’t know the aerodynamics of the full trailer until the hatch-lid and haunches are built.  130707_1008_kids+trailer

On our second night we stayed at Tule Lake, after visiting the Japanese-American internment camp site. Apparently the TuleLake camp was famous for housing dissidents and (Japanese)Americans who would not sign an insulting “loyalty oath.”

On our third night, we stayed in a park in Trinidad, CA.


Trinidad is stunningly beautiful. In many ways it is the beginning of the Pacific Northwest coast. It also has a fleet of tiny, working fishing boats. I thought it would be great to meet some of the boatwrights to confer about the Guppy trailer, since it is built like a wooden boat.



…But first, we had breakfast at Trinidad’s Beachcomber Cafe. Fabulous place.



They have displays of where their ingredients come from.


Trinidad is very different from Arcata, the hippie college town just down the road. Still groovy-north-coastal, but much more low key.

Teardrop Trailer 001

After breakfast, we went outside and lo and behold: a boat guy had found us. Actually, when we parked in town to go to the cafe, we parked in front of Ken Bechdol’s house. He has built many wooden boats, but the partially-complete trailer intrigued him. Ken emailed me the photo above; note that he laid a yardstick in the image for scale. Also note how incomplete the Guppy is: we used cling-film to close the window-holes. You can see straight through the gap between the door and the jamb. There is even a bit of a shark-fin where I have not trimmed down the side-paneling above the door.130707_1130_Ken

Ken showed me six of his boats. [Hopefully when he reads this, he will remind me of the names of the four wooden boats. A leeboard skiff? A gig? Argh, I did not write them down immediately. But the two coracles are so distinct they are hard to forget!]

Here, Ken is showing me that on the rail of the boat he left the edge of the plywood exposed, so that he could show the thinness, and humbleness of the actual hull material. When the wood is finished this nicely, though, that sandwiched plywood edge looks like decorative inlay.130707_1133_BechdolBoat

One of Ken’s strip-plank boats, suspended from the rafters of the shop/garage. 130707_1625_beadingArcata

After conferring with Ken for one highly-informative hour, we headed down to Arcata and made beaded jewelry. Lizzie came up with a brilliant design for a pair of earrings! When I get the chance I will post images of them.130707_1932_PegHouse_KeylockScarfJoint

On our way back from Arcata, we stopped at the Peg House for coffee and snacks. The cashier pointed out the elaborate carpentry shown above. He did not know the name of the joint; I believe it is called a key-lock lapped scarf joint. And yes, that is a portrait of The Man In Black, affixed to the underside of the joined beam.

The drive back was uneventful; the Guppy continued to handle smoothly. In Petaluma, our trip-meter marked 1,000 miles traveled.

Guppy trailer, part 4: assembled

At last, after a month of fabrication, I was able to assemble the parts on the morning of June 23, 2013. Strangely, it began to rain that day and drizzled off and on for the next two days–something I have never seen in California in June! But I had varnished so many of the components that it did not matter, and I was thankful for the cool weather. Sophia took the photographs, and Gabriel helped with the assembly:





Above, I am bolting down the left-side wall to the deck. The deck is a simple 4X8 sheet of 1/2″ plywood. I didn’t use the flatbed of the trailer itself as the deck because it is a mix of steel at the edges and rough pine planks across the middle–in fact the manufacturer would not give me shop drawings of it, and I had to design the cabin while I was waiting for the flatbed to be built and delivered to the dealer. So while I was assembling the walls and ribcage, I had the 1/2″ cabin-deck sitting on wooden crates. You can see one of the crates in this image, marked “computer.” By holding the deck up, I was able to install bolts from below into the L-brackets at the base of each wall-stud.


I attached the rear bulkhead and the left wall to the deck; then I could attach the ribcage. Here you see the “Pony” 90-degree vises in action. A few other things to note in this image: 1) Two weeks earlier I had scabbed the curved pieces together into five ‘flying’ ribs as well as top-rails attached to the sidewalls. To make sure they matched, I clamped them all together and belt-sanded them to a smooth match. Before unclamping the ribs, I marked across them every 4″. This greatly simplified the process of assembling the ribcage (see Part 3). You can see a few of the marks in the foreground. 2) You can also see the roughness of the rib-assembly. To use wood efficiently, the nose-curve had to be compiled out of short arcs of wood, glued together. On the left side of the picture you can see where the upper “back” segment overlaps with the upper “nose” segment and the lower “nose” segment of each rib. 3) Just beyond the ribcage is our neighbor’s car. Yes, I did indeed build this trailer in a parking-space.


With the ribcage and one side-wall installed, I then glued and screwed the first layer of 1/8″ plywood on the inside of the ribcage. This image clearly shows how the cabin-structure is ‘up on blocks’ for the moment, while I counter-sink and tighten the bolts that hold the ribs and wall studs to the deck. I have also cut and framed in the left side window openings, and the upper vent-openings. I could not wait any longer, because the next step was to install the rigid foam insulation into the wall-voids.


This view from the right-front shows how the structure is coming together. I installed the ceiling/nose layers of plywood before bolting on the right sidewall. That sequence was driven by the need to get big sheets inside before the openings were too small to admit them.

This turned out to be a problem because the stressed-skin ribcage flexed open a bit, and it was very difficult to get the right-side wall to align as I installed it. In retrospect, I would prefer to bend the interior sheets of plywood to the ribcage *after* both walls are installed. But how? The trapdoor in the rear bulkhead (see the image above) points toward a different solution. Rather than a partial-width trapdoor, you could make a full-width door–meaning that the bulkhead would not come down to the deck. Then you could slip full-length sheets of plywood into the interior space from the back, and bend them into place on a completed wall-and-rib frame.


I got the right-side wall installed. Then Lizzie helped me roll out sheets of thin foam underlayment before removing the wood blocks and dropping the cabin onto the flatbed. The thin foam underlayment comes from IKEA; it is what you lay down on a floor before installing their masonite faux hardwood floors. We had a roll of the foam left over after we installed such a floor in our living room.

Here you can also see the insulation I am cutting and jamming into the wall-cavities. Again, unexpectedly cool look! Crinkly yet shiny, like a 1960s space-capsule. I cut the foam with a kitchen knife. A word of advice: if you can’t stand the sound of squeaking styrofoam, this is a difficult step. Lizzie and the kids literally had to stay out of earshot during this entire process.


Next step: laminating the outer skin onto the ribcage. My neighbor Keith loaned me a set of cargo-straps, which I used to apply even pressure across the ply skin as I glued/screwed it down to the ribs. Other people, with more time, more clamps, and a garage, might be able to do this without screws. But one of the defining features of this project was that I had to get it built as quickly as possible.


View with the left side skin installed. Since I was using stainless-steel screws, I decided to just glue-screw the sidewalls and leave the screw heads exposed. The white vinyl tape on the flatbed marks the position of each wall-stud so I could align my screws.


I began the major assembly on June 23. By July 3, I had the structure insulated, had the outer skin installed, had it bolted to the flatbed using long, squared-off U-bolts. No windows, and the back end remained completely unfinished. The last thing I did before we towed the Guppy for 1,000 miles was install the door.

Guppy Trailer, Part 3: fabricating the components

I have been cranking away on the trailer as fast as I can, so I am inserting this blog post after-the fact. This page describes the fabrication of the components.


Here is the left sidewall, under construction in our living-room. A few things visible in this image:
1) On my dad’s advice I sanded the first layer of varnish with 400# sandpaper, cleaned off the dust, and applied a second coat. My goodness! what a glassy sheen!
2) The unvarnished white stripe in the foreground is where the rear bulkhead will be attached. I left it bare for better glue-adhesion.
3) Wall studs have been glued and screwed to the outside of the wall-panel. Two un-trimmed studs are visible at right, and a regular grid of screws across the face of the wall panel are faintly visible.
4) The inside-rib along the top of the wall-panel will be a guide-rail for the thin ply that I will bend in to make the ceiling.


Here is the same left-side wall panel, with the varnished inside face laid down on the new flatbed trailer. Rick Storrs made a great suggestion for windows which saved me time: rather than figure out operable windows, I would build simple, fixed windows and install vents to provide for ventilation. I placed five vents in the left wall: three low, and two high. I needed a rigid, cylindrical spacer to run the vent through the wall-insulation. What you see in the picture above is 3″ internal-diameter pipe, cut into 1.5″ segments, to provide a rigid passage between the outer and inner layers of the wall.


Here I am correcting a major mistake. I thought I had bought 1/2″ ply, in which case 3 layers would add up to 1.5″, the same thickness as the wall-stud depth and insulation thickness. However it was 3/8″ ply, so 3 layers added up to 1.15″ (with glue), not 1.5.” To make it work, I had to peel back the topmost layer of ply lamination, then add one more 3/8″ to flush it up to 1.5″.


And here is my biggest mistake: I used aluminium L-brackets at the base of the wall, to be fastened with stainless-steel screws. When exposed to moisture, the electrolytic reaction between these two metals would disintegrate the aluminium.

My solution was to coat the bolt-ends with Lexel, which is like silicone sealer but even stickier. My hope is that by entombing the connection, I will minimize the chances that water will be able to trigger the electrolytic reaction.


After many days of cutting, laminating, and grinding the ribs until I had full-length composites that matched, I began joining them together using cross-blocking. The easiest way to attach the blocking was to hold it against the rib using a “Pony” 90-degree vise. A dab of glue, a pre-drill and an end-screw, and the connection was done and strong. End-screw construction meant that the blocking could not line up across the rib-cage, but I did not worry about this because the ribcage would be covered, inside and out, with layers of thin bent plywood.


What I had not anticipated was that the overall pattern would be so beautiful! I’m glad I photographed it; I’m sorry now that it will disappear under a smooth layer of plywood.


Now, the key components are fabricated. Foreground: you can see the L-brackets, epoxied onto the blocking of the rib-cage. Background: on the far left is an old futon frame [not part of this project]; the plain rectangle of plywood next to that is the rear bulkhead; on the right are the two side-walls. I still haven’t cut the window-holes in that lovely glossy surface, but time-pressures will compel me to do that soon enough.


Love and Justice

[Written on the day that the Supreme Court overturned DOMA and dismissed the Prop 8 appeal, enabling the expansion of marriage-rights in California.]

Today I can wear my wedding-ring with pride.
Today our wedding-vows are affirmed.

Today, Love triumphed. The black-robed ministers of justice acknowledged the higher power of Love and the recognition of commitment, pushing aside all other reservations.

Justice reveals herself to us. Her radiance is Love; not prejudice, not fear of something different. Though Love may be constant, Love also provokes inevitable change; it opens our souls to face the unexpected.

Today I can say to my children that marriage is about that commitment to Love. No exceptions. Today, the shadow of cruel discrimination begins to lift. Justice smiles upon marriage, blind to the gender of those who commit so completely to each other.

When we stand together as a community to bear witness to a new marriage, we are often called to renew our own wedding vows. For men and women who have long enjoyed the right of marriage, today stands as a tremendous affirmation–a strengthening–a renewal of our own commitment to marriage.

Today I wear my wedding-ring with PRIDE.

Guppy Trailer, part 2: cutting the ribs

The next task was to design the Guppy cabin itself. A rib-and-skin scheme, infilled with rigid insulation and overlaid with thin sheet aluminum (0.24 ga, if I can manage it) seems like the lightest overall design. I started with 1/2″ marine ply sheets, to be cut into 1.5″ wide curved ribs. Below is my first cut-sheet pattern:


What I have tried to do is use as much of the sheet as possible. I then scaled up the original drawing to 1:1 scale;
printed it on multiple sheets of paper;
pieced them together on a sliding-glass door and taped them together;
laid the paper-mosaic onto the plywood sheet;
slipped carbon transfer paper under the mosaic; and
traced the design onto the plywood using a ballpoint pen.


The second cut-sheet leaves a lot of unused material between the irregular “chevron” shapes of the galley-hatch ribs. That wood will be cut up into blocking to go between the ribs.

Here are the two cut-sheets used for the structural ribs, at 1:1 scale:


Guppy Trailer, part 1: the basic concept

This summer Lizzie wants to go on a grand-loop road-trip around the U.S. with the kids. We have thought about various ways to do this, and we have decided upon building a teardrop-type trailer which we will tow behind our VW Golf (a.k.a. Glove). Why? 1. We need something convenient to camp in. At first I was not sure that I was going to go on the trip (I tried to get back to Kabul for August), and Lizzie wanted a secure place to sleep. 2. Buying another vehicle would have cost far more, even if it were an ancient VW Microbus.

I researched teardrop trailers online, and found out two important things. First: teardrop trailers emerged during the Depression, as families could not afford to stay in hotels. So our choice to build a teardrop is historically consistent. Second: it is very difficult to get plans of a teardrop trailer (for free). However, these trailers emerged at about the time that plywood became available, and for many D.I.Y. families, the 4′ x 8′ module of the plywood sheet was the standard-unit basis for the design. Here is my version:


Initially my design had a simple sloped back like other teardrops, the shape that gives them their name. Then I decided to add a swallow-tail to the galley hatch to separate laminar airflow over the trailer from backdraft turbulence behind it. Most recent cars have some version of this lip, so my hunch is that this will work better. Sophia looked at the new design-shape and said it looked like a guppy. And so this design was named!

But what would the Guppy sit on? I was not familiar with trailers, but our neighbors are. We took a look at a flatbed trailer parked nearby, made by Carson. From the manufacturer’s labeling on the trailer I realized that the flatbed has a VIN, and is engineered to comply with DOT standards. Essentially, the steel flatbed trailer is the vehicle, and the Guppy is merely the cargo, or payload that sits on the trailer. So I ordered a ‘flatbed mini’ from Carson, with a 4′ x 8′ frame, and an axle assembly rated at 2000 lbs. For this trip to work, the Guppy must weigh far less that 2000 lbs; maybe 300 lbs max. Part of the reason to design and build my own is to make it as light as possible.

And how would we tow this trailer with a Golf? We had to order a trailer hitch. Fortunately JC Whitney sells Curt trailer-hitch frames that fit a 1998 Golf, at $225. Installation was a pain, because the Golf is a unibody construction so there is no chassis nor any pre-made attachment points. I had to bore out 3/8″ bold-holes on some very irregular, compound-curve surfaces to mount the hitch frame.

Custom frabrication and the 90% rule

I am a prototyper. I finally came up with this self-description when trolling the aisles of a plumbing-supply store, browsing the fittings to see what might be useful. [Consider the hose-clamp and its many uses: better than duct tape]. The owner asked what I was looking for. At that moment I was getting parts to fix our kitchen sink; but to explain my wider survey of the hardware in the store, I had to explain that I make peculiar things or customize everyday objects in peculiar ways. It is a method of meditative relaxation for me; something like knitting or crossword-puzzles for others.

Time permitting, I will post some of my peculiar “mods:” the plywood bike trailer; the carabiners-as-bike-trailer-hitch; the bike shack built into a parking space; the futon covers that strap to the frame; the clip-on climbing treads for randonee skiing; the plywood carry-boxes. My current project, which I will certainly write about in the coming weeks, is a “Guppy Trailer” for our car, to enable us to take some serious road trips.

Increasingly, as I get older, I try to avoid rediscovering the wheel whenever possible; editing existing designs and materials is so much more efficient! Which is where I came up with the 90% rule. The delightful thing about living in a mass-production society is that many necessary things are really inexpensive. Cloth, stainless-steel kitchenware, plywood, screws. Each of these four items is fantastically useful, and I appreciate them especially from an historical perspective. For example: metal fasteners used to be so difficult to produce that Europeans would burn ruined houses and sift through the ashes to recover the nails and hinges! Then came wire-cut nails in the 1830s, and a revolution in construction. As for stainless-steel knives and forks? Medieval smiths would have regarded them as near-miraculous products.

Factory-made cloth is the better-known modern material. During the Industrial Revolution, spinning-jennys and power-looms reduced the cost of cloth by about two orders of magnitude. I believe it was Dolores Hayden who noted that this led to a rise in literacy among women, because they did not have to spend so much of their time carding, spinning, and weaving. They still had to hand-sew clothes; but toward the end of the 19th century, sewing machines sped that up that process as well.

So I enjoy the marvels of the industrial world, even as I draw attention to inequalities and exploitations in the production process. We can have the efficiencies and marvels of modernity without screwing over the workers. Furthermore, we can fine-tune much of what we buy because it is made in a generic way; for instance, off-the-rack clothing can be adjusted for far less cost than clothing custom-sewn from a pattern. What mass-production provides is stuff that we can consider at least 90% satisfactory. Tweaking it that last 10% is satisfying in itself, but it also takes far less time.

Kora Paddy Cultivation

May 29 edit: Oops! In the PDF posted on April 30, I accidentally skipped pages 2-3 (Sorry Dommo!). This scan has all the pages, and was scanned at 200 dpi, so it is only 10 MB.
KoraPaddyCultivation_1953. [with all the pages included]
I have left the incomplete file below because it was scanned at 300 dpi, and if anyone wants to extract the photos, the scan-resolution is as high as the original halftone resolution of the publication (meaning you can’t get better images out of this document).

April 30: This post is a placeholder for downloading Kora paddy cultivation: Japanese method as experimented improved and developed at Kora centre [PAGES 2 AND 3 MISSING]. (Bombay: Gandhi Smarak Hidhi, Krishni Vistar Vibhag, January 1953). It is a fascinating document of international cooperation in the early post-war years of ‘modernizing development.

Rough diagram of Luna South Pole development

Recent American and Japanese missions have begun to map and sample the south pole of the moon, since it is currently considered the best candidate for a permanent Lunar base. Here I present a sketch of the south pole, with steps in Lunar base development:

Luna south pole, development concept

On the diagram I describe five steps in base development. The first step is to settle on Malapert Mountain, since this mountain seems to be permanently in sunlight. It is the best place to set up transmitters and solar panels brought from Earth.

The second step is to develop a landing site some distance from Malapert peak. Since the moon as (almost) no atmosphere, landings will be powered, and will kick up dust. So an early test of crude refining will be to create pavers for a landing-area to minimize dust-blow. The next problem is to figure out a regular transport system that optimizes a) simplicity of construction, b) minimal energy consumption, and c) speed of movement. Perhaps a monorail would actually be a good idea for once?

The third step is to develop a major electric generation, storage, and distribution system. Solar power, thermoelectric, and charged-particle harvesting are all potential significant sources of electricity. Storage? Angular momentum in massive flywheels spinning on superconductor maglev bearings. The mass of the flywheels could be lunar rocks held in metal nets. Most of the basic activities of the base will require large amounts of continuous, on-demand electricity, so this system needs to be developed early.

The fourth step, in concurrence with steps 2 and 3, is to research the area intensively, before disrupting it through industrial development. I think a lot of research scientists would cringe at the prospect of disrupting the South Pole with industrialization. But for long-term development of a human presence in space (and other major research projects), I think the pristine condition of Luna’s south pole needs to be sacrificed. We need the site for mining, refining, manufacturing, and launching products into Earth-Lunar space. I would much prefer to have toxic industrial processes carried out on Luna than on Earth. I would prefer that we obtain rare-earth metals from a Lunar strip-mine than poison aquifers in poorer regions of the Earth (such as New Guinea). I hope that we can agree on areas and rules of Lunar exploitation through the United Nations.

Speaking of treaties, the fifth step will need to be carefully monitored. A high-capacity mass-driver on the moon could be used as a major weapon. So terrestrial governments will have a persistent interest in restraining it from ever being used thus. The peaceful, intended purpose of the mass-driver is to use electricity to launch products off the moon: water separated into hydrogen and oxygen, refined silica wafers and electronics components, etc. For delivery to Earth, products could be packed into a simple drop-glider with an ablative heat-shield made of silica.

Colonizing Luna: from engineering to planning

Here is an example of an item that we need to develop and test extensively: spinning habitats. Herman Potocnik suggested this system of creating false gravity through spin in 1929, and the ‘wheel-in-the-sky’ space station became a popular motif of pulp sci-fi book and magazine covers in the 1950s. But so far as I know, no space agency has ever actually implemented this idea. We know that living in microgravity conditions is seriously harmful to humans; we now have decades of research on that. We suppose that a spinning habitat will solve that problem. But a spinning habitat is also a practical problem: What is the minimum radius? Can we get most of the benefits from, say, 0.8g centripetal acceleration? How do we dock with a spinning habitat? What is the lowest-mass configuration we can design? For example, a ‘spinning bolo’ of two pods–perhaps one is the occupied capsule and the other is a service module–might be less-massive than the Apollo-era configuration for going to the moon.

My overall point, with this spin-gravity example, is that we still need to develop practical experience with a variety of systems to keep humans healthy offworld. We imagined them long ago, but all the variables of a real-world system cannot be anticipated in hypothetical designs.

Here, I am arguing that we step out from the engineering approach to the urban planner approach. Engineers (rightly) try to pre-anticipate every contingency. Therefore engineers need to work with relatively simple, bounded systems compared to the open and indeterminate complexity of a city. Urban planners think very differently about problem-solving because the complexity of cities cannot be ‘accounted for’ in any totalizing model. Emergent conditions are typical within open, complex systems such as cities–in other words, they generate their own indeterminacy. Thus, risks cannot be fully modeled and forecasted ahead of time. Riskiness and other aspects of a complex system have to be actively managed in-process, as new conditions emerge from the system itself.

If we develop larger, long-term extraterrestrial habitats where crews perform many tasks over extended periods of time, these habitats will move from the manageable complexity of singular missions to the open complexity of human communities. Therefore, the mode of thinking needed to manage the process of human expansion into space will need to move away from an engineering-paradigm and towards an urban-policy paradigm. Perhaps the most nerve-wracking aspect of this shift will be the management of risk. We will need organizational structures, expectations, and ethical understandings to cope with non-military environments that are totally artificial, and in which there will be accidents with major fatalities. Consider a remote outpost where something goes wrong with the power or life-support system and the entire crew is lost before they can be rescued. When that happens (it will), the institution must be designed so that human error is acknowledged, but the primary consequence is learning. The dying crew’s primary responsibility will be to study the failure as it is occurring, so that as David Brin argued, they can pass on the lesson about what killed them.

If Americans are to participate in this new phase of human expansion into space, we need to get over our cultural phobia about mortality. It may be that astronauts should all be grandparents who can say goodbye to their families with some comfort. In ships with lighter radiation-shielding we may contract lethal forms of cancer, but until we can get enough fuel and shielding-material available outside of Earth’s gravity-well, we should consider relying on people willing to face known hazards in order to blaze the trail.

Throughout most of human history, humans have faced these sorts of risks. I have watched Afghan families take far greater risks on a regular basis. What we need is a ethic that allows an organization to strengthen and learn under conditions of lethal risk. Since about 1950, Americans have only tolerated such risk in military service, as a part of patriotic sacrifice. Industrializing the Moon does not fit the military-heroic ethical framework. We will need to develop an ethic of risk-tolerance for human spaceflight that allows for experimentation, innovation, and deaths in the somewhat prosaic process of offworld industrial development.