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We asked Steven Roberts, the venerable “high-tech nomad,” best known for his net-connected, gadget-laden Winnebiko and BEHEMOTH bike projects from the 1980s, to write a series of articles on the amazing new mobile projects lab he’s building, dubbed Polaris. This tricked-out trailer will allow Steve to be ready-to-make wherever he parks, with all manner of maintenance, fabrication, and repair machines, tools, and supplies on-board. It’s a hackerspace on wheels. You can read the other installments of the series here: Part 1, Part 3, Part 4. — Gareth

Make it anywhere, part 2: Mobile lab substrate

By Steven K. Roberts

nomadHead_2.jpgIn the first article of this series, I introduced Polaris, my mobile lab, a distillation of the huge and inefficient shop building that I’ve been using for over a decade. This new system is allowing me to haul a fully functional workspace to a marina, where I’m immersed in a geek sailboat project that requires extensive fabrication and tinkering facilities. And it’s also accompanying me to Amateur Radio Field Day, and (hopefully), next year’s Maker Faire Bay Area.

There are so many applications for portable workspace that I’m writing a book on the subject, as well as guest-authoring a series here on MAKE.

Let’s start by taking a look at some of the specifics for creating your own mobile lab. The harshness of life on the road requires attention to issues that don’t arise in traditional structures except perhaps briefly, during earthquakes; vibration and lateral acceleration can destroy cheap furniture and make a gumbo of your parts inventory.

make overall Make it anywhere, part 2: Mobile lab substrate

The first decision involves sorting through trade-offs in robustness, hackability, and cost to choose the substrate itself: van, RV, trailer, container, bus, truck, or other vehicle. I’m not impressed by the construction quality of most RVs, for example, but they’re common enough to have a pretty good cost/performance ratio, and in a declining economy, can often be found at a tempting price. The trouble with them is that most interior space is devoted to human comfort, and you’ll thus end up with either a small lab tucked into remaining corners, or a major operation to gut your rig; neither very appealing.

Shipping containers, at the other extreme, are extremely rugged and secure (from intrusion as well as the elements). They are available cheaply in US port cities, piling up due to global trade imbalance, and 40-footers can be had for as little as $1-2K, if you shop around. They’re not very mobile, however, unless you own a large truck; moving them is a turnkey process, but you’ll pay. The good part of this is that you can ship one pretty much anywhere in the world and assume that it will arrive in one piece. Containers are also dimensionally standardized, and can be combined in a variety of ways to build a whole compound at a fraction of traditional construction costs. If you need to conjure a cheap shop building and don’t plan to move it very often, this is an excellent option.

Still, I prefer more convenient mobility (and more space than a van), so for my application, I chose a utility trailer. These are made by about a dozen vendors with various levels of quality and a wide range of costs. My choice was a 24-footer from Wells-Cargo (this is my third from them) but it’s by no means the only game in town.

make empty lookingaft Make it anywhere, part 2: Mobile lab substrate

Trailers of this class are basically big mobile boxes with plywood floors and skinned walls, with metal ribs and a lightweight roof structure. They range from 8-48 feet long and 6-8 feet wide. They’re easy to hack, and can be purchased with lots of useful options, including insulation, windows, E-track, and tie-downs for lashing, power, lighting, folding steps, ramp doors, roof vents, air conditioners, and more. Mine was off-the-shelf and fairly basic, so the first job was to take it apart and insulate walls and ceiling… not a fun job.

The structure is simple: exterior steel skin supported by “hat section” ribs that also carry the internal plywood sheathing. The space between is so thin that I had to peel away about half of the R-13 insulation batt thickness; the net effect is much better than the original uninsulated space, but I wouldn’t call it cozy.

make insulationwall Make it anywhere, part 2: Mobile lab substrate

The roof involved a different method — rigid R-Tech skinned foam, an added headliner, and wooden cross-members to clamp it all in place. Your mileage may vary considerably, depending on trailer construction. If you have the opportunity to order a unit to your specs, I highly recommend letting them do this nasty job. In my case, the insulation project dragged on for a few weeks.

The boundary between wall and ceiling created an interesting challenge — a combination of the non-square roof crown, curvy aluminum cap rail, and my own contributed imperfections. I ended up making a dozen fitted doors with cabinet hinges, stuffing insulation behind them, and using the newly created full-length channels (with gaps every four feet) for cabling:

make cornerdoors Make it anywhere, part 2: Mobile lab substrate

With the shell of the trailer now insulated and buttoned up, there was still a major issue to address before bolting down furniture. I was clearly going to need a place to install the systems — power management, security, radio communications, and networking tools. The obvious spot was at the bow, inside what Wells-Cargo calls the “nose cone,” which is visible in the opening photo of this article.

Oddly, they had installed this as a retrofit to the basic square trailer nose, leaving the metal skin but unaccountably removing all the screws (which explained the booming/rattling sound that had been annoying me). After painfully hacking out the sheet steel with tin snips and other implements of destruction, I had a beautiful open space behind the plywood interior skin, a perfect place to install a door that would carry breaker panels and other controls:

make nose door open Make it anywhere, part 2: Mobile lab substrate

The latch is a Southco multipoint unit that engages receivers at top and bottom, making it easy to open and close the door with a single twist-lock. I insulated the fiberglass nose with a couple of batts, and mounted the 30-amp marine shore power connector near the bottom (just above the trailer tongue shelf where the generator sits). In part 4 of this series, I’ll show you what was done with this space, which is now packed with wiring and control panels.

Finally, there was one remaining “substrate” issue that was annoying me: with side and rear doors closed, the lab-to-be was pitch black inside. Since the trailer had not come with optional windows (and my planned interior layout gobbled all the wall space anyway), the only airflow was through a couple of tiny flow-through vents designed to prevent mildew. Besides, when sequestered inside the rig, I want a way to peek out and see who’s pounding on the door before releasing the lock!

In the nautical spirit, I prowled eBay and picked up a discontinued Beckson opening port (a small window made for sailboats, with good drainage and seals). Given my 6′ 4″ height, I wanted this close to eye level, and that ended up removing a structural beam in the door that connects the upper hinge to the frame.

The solution is at least as strong as the original, and gives the rig a somewhat salty air: I carried the door structure around the port hole with a frame of marine plywood…

make door port inside Make it anywhere, part 2: Mobile lab substrate

With the outer rim of the port silicone-sealed to the door and flush with the surface, it presents a sleek appearance; a small curtain will keep the curious from peeking in. The window is attractive and useful, but will not replace the video cameras that provide an all-around view internally or over the web… but I’m getting ahead of myself!

In my next installment, I’ll describe the furniture choices, tie-down methods, and tricks for keeping almost 900 drawers from flying open and spilling their contents when I’m on a bouncy road.


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