moroza

How about a sign that says "Warning: proximity sensor for automatic toilet dump." And maybe have a little auxiliary holding tank for "warning shots"? There's also the classic, "Do not tailgate; vehicle sheds parts." Helps if the vehicle looks the part, of course. And my personal favorite:

Hey waitaminute, you've got a -78 cab in the first shot, and a 79-83 in the second... cab swap? Why? Staying tuned...

I don't own what came from a factory as a motorhome, but... 26.

Wouldn't that be weaker than the triangle structure I have now? Anyway, that upright member is for keeping the walls from flexing too much, and supporting a window. I don't see it supporting much other weight. Duly noted, anyway. More comments like this, please! 1. Good idea, and I will do something similar temporarily, but I plan on adding a second tank opposite the first, so other than little cubbies there won't be much room down there. I plan to keep at least some of my drinking water and all of my batteries inside the insulation layer, for function in extreme cold. I am considering making space for temporary mounts for the batteries as low and centered as possible, in case I ever really need to squeeze out an extra couple degrees of traverse angle. 2. There'll be exterior storage bins at least in front, if not also behind, the rear wheels. I did not include them in the drawings because they are outside the structural and insulation layer. The departure angle looks so good because I completely redesigned my project to maximize it. I can't get any better without getting real creative with the rear springs (not shown, but they are the drag point right after the full-sized spare). Right now, the spare sticks out a good bit, and I'm not sure if that's a very good thing (hang a steel plate under it and it's a very good bumper) or if I should relocate it to maximize the angle. I lived in my car for about a year, got hooked on that lifestyle, but decided that an old BMW wagon just wasn't appropriate for it. Carving corners at 200kph doesn't mean much when I get stuck on my way to a campsite, then spend all night freezing in the back of the car because there's no heat or insulation. I call this project a "tinyhouse", but it's not a house scaled down, it's a car scaled up.

I played with a few different configurations of skin material and thickness vs. stud material and thickness, and came to the conclusion that triangulation with studs is much lighter than with skin. At least, that's how it was with wood/plywood. I would think that triangulation is a lot more important in a structure that sees frequent side to side loading, rather than buildings.

Thermal bridging. See the first pic for how I'm getting around it. Well, I'm not using any fiberglass. The only heavy plywood is on the floor and a bit on the roof. The wood studs could probably be thinner; all they're for is supporting the windows, and keeping the thin wall skins from flexing too much. The alu studs might get thinner, too. Weight is the reason I redesigned the whole thing to use alu instead of steel. My previous scheme involved steel tubing of various shapes and sizes, plus the same skinning materials as this. I estimated 280kg before interior fixtures and whatnot. With this, I'm hoping for more like 230kg. I've yet to run weight calculations. For now, I'm looking for feedback on structural design. Like does it look adequately triangulated? Is part of it overbuilt? Underbuilt?

I've seen and studied the Super Camper. Nidacore is too expensive and underinsulated. I can take screenshots and upload them as JPEGS, of course, but you won't be able to fly around the model. I guess I'll try that. Here we go:

Any armchair (or actual) engineers around here? Or anyone else with $.02 to share about my plans to DIY a motorhome? I've got an '81 longbed 4x4. I want to build my own for several reasons, chiefly that I want it heavily insulated. Current plans are 3 inches of polyurethane or polyisocyanurate rigid boards all around, maybe more in the roof. Structural materials are mostly riveted aluminum, with some wood thrown in a few spots. For planning, I have it nominally as 2x1" beams, but actual pieces will depend on what I can find. It'd be great to come across a stash of broken aluminum ladders, and chop them up for beams. The "stove" refers to either the smallest Ammocan stove, or something very similar of my own construction. I plan to use propane only for cooking, and diesel only for moving the vehicle. Window shapes and positions are approximate; actual details will depend on what windows I salvage from something else. Really, that statement applies to everything in the design. Walls materials and their thicknesses, inside to out: 3.2mm plywood (1/8) inside, except around stove, where it's cementboard and alu skinning 50.8mm alu and wood studs, insulation between them 25.4mm more insulation 0.6mm (0.019") alu skin on outside floor: 15.9mm plywood (5/8) 50.8mm studs and insulation 25.4mm more insulation 0.6mm alu skin on outside (bottom) roof: 3.2mm plywood (1/8) inside, except maybe around the stove 38.1mm insulation 50.8mm studs and more insulation 12.7mm (1/2) plywood 0.6mm or thicker alu skin on outside (top) Here's my SketchUp model. I couldn't find a 1st gen cab, so I took a 3rd gen and fudged it to similar dimensions. The collection of stuff in front of the truck is a cutaway of the wall/floor joint, illustrating my positioning of the structural beams to avoid thermal bridging. Er...how do I upload a .skp?

I'm still in the planning stages of a DIY camper build on an '81 Toyota 4x4 frame. Right now I'm trying to decide between a side-door or rear-door layout, and hoping some folks can weigh in with their experience and thoughts on the relative merits of the two designs. The competing layouts I'm considering are 6.2 and 9: Bright red lines represent full-height floor-to-ceiling partitions (closets). Dark red are partial-height (bins). Dark purple is a sideways Murphy bed in half-out (couch) mode, light purple is in full-out (bed) mode. The gray X-ed box represents the floorspace taken up by the woodstove and everything it comes with. The cross-section view is looking forward. There, the blue is the shape of half the bed's mattress, the green is a fold-down table/counter, and the curved dark red is the shape of the cab cutout. The white boxes are the wheel wells. Constraints and externalities: * The space is 4' tall by 5' wide by 8' long. I will not make it longer, wider, or taller, for various reasons. * The back of the cab will be cut out and joined with the rear box. "Flow" between the cab and box is very important to me. I'll eventually have a captain's chair mount for the passenger seat. * The bed/couch design is pretty much fixed. It must be full-width and be able to fold away. What the pros-n-cons basically boil down to is this: a side door feels nicer to live with and has more cargo room. But much of its cargo room is at the back of the vehicle (real heavy stuff like water and batteries can still be in the center, though). Maybe I'm still stuck too much in performance-car-thinking, but that seems like bad design from a moving-vehicle perspective. Anyway... your $.02?

I've got a lot of steel tubing available here, as well as angle iron and some heavier C- and I- beams. The tubing is (I think) 2" x 2", 1/8" thick, the other pieces vary. There's also a lot of old leaf springs, some highway stakes, at least one big piece of diamond plate... and that's just what's here and otherwise trash, not counting whatever I buy. Should I make the whole thing out of steel, or just a rollbar-shaped core structure, or just the floor...?

That stove looks excellent. I've got a whole lot of old ammo cans laying around here, and I bet I could make something like it, but with an exterior air intake and maybe extra heat shielding. Work's been slow; I'm rebuilding the front axle, relocating the rear, and doing little this-n-that things to the rest of the truck. I've also been doing unrelated welding projects, which have made me realize that making a steel frame isn't out of my abilities like I initially thought. I know that steel is stronger than wood in some ways, not others. Who here can tell me what about making some of the structure out of steel, to gain strength or lose weight?

I like those ammo-can stoves; they're about the size I had in mind when first planning things. I'd want to add a lot more heat shielding to mine, though. Now that I've figured out a nominal value for how much heat output I need, I'm leaning towards a more complicated but compact heating system: a tiny stove, maybe the size of one of those ammo-can ones, with extensive heat shielding, that normally gets stored in some cubby, but that I can bring out and attach to two semi-flexible ducts: one for exhaust, one for outside-air intake. When I need heat, I bring it out, hook it up to the ducts, burn what I need, let it cool, then put it away and save some valueable floorspace.

Most commercially available LEDs are a balance between cost and output, with their "purer" light somewhat mitigating the lower actual output. You can get LEDs that are just as bright as incandescent or compact-fluorescent bulbs (Audi and some other cars are coming with LED headlights), and they'll last longer and draw less, but they'll cost you a lot more. I have two 5W LEDs in my yurt, and it's an acceptable amount of light for reading and cooking and whatnot. I'd say they're about equivalent to two 25W regular bulbs, while costing about twice as much and drawing five times less power.

Regarding insulation, here's the back of my envelope: Surface area of the camper box, including a hypothetical wall between the cab and rear, is 19.5 square meters. Rigid foam has a thermal conductivity of 0.035 W/(m*K), which for 89mm gives a thermal resistance of 0.089/0.035 = 2.54 K*m^2/W. Thermal transmittance is the reciprocal of thermal resistance, in this case 1/2.54 = 0.393 W/(K*m^2) With 19.5 m^2, I get 7.67 watts of heat lost through this insulation, for every degree Kelvin (same as Celsius) temperature difference. If I'm in a typical Norcal winter (5*C) and want it to be 25C inside, that's a gradient of 20K, so I need to be generating 7.67 * 20 = 153W to maintain that temperature. In a murderous arctic winter of -75C, that 100-degree gradient means I have to generate 767W, which is about 2618 btu per hour, which is about a sixth of the smallest woodstoves I've seen. A human body makes 80W of heat when sleeping, about 110W at rest, and over 1000W doing heavy work (the first two numbers are pretty consistent among sources; I'm not sure about the third, though). This isn't including the insulating value of plywood (very small), interior cabinets and whatnot (moderate), nor losses due to 2x4 framing (small to moderate) or windows (variable). But the back of my envelope suggests that me doing some pushups now and then will be enough of a heat source no matter how cold it is outside. So... I... don't... need a woodstove at all? Can someone check my math and reasoning?

Thanks, I'm glad to hear a space this size doesn't need much in the way of heat generation, more in retaining it. There'll be a smoke alarm, CO meter and alarm, at least two fire extinguishers, and variable vents in addition to the doors and windows. I do intend to seal it thoroughly, so outside intake air is a given. (Minimalist indeed)