Four Wheel Campers – My Favorite Truck Camper Design For DIY
So how do you make your own “Four Wheel” style homemade camper?
Let’s start with the framing. The skeleton of the 4WC is made of sturdy but lightweight aluminum framing. You can find videos and plenty of photos showing what the framing system looks like, in case you have the resources and skills to do the welding yourself. (In my feature article I include a video by a guy who built his own aluminum 4WC, with a few interesting twists. He estimates the project cost just under $5000, spending about $1200 on aluminum alone.)
Assuming you're interested in making your own DIY Truck Camper on the cheap as I am...
The most readily available and inexpensive framing materials are going to be wood. As I describe in my related articles on How To Build Your Own DIY Truck Camper, it's really not that complicated! You're essentially going to build a wood shed that sits atop your truck bed rails. The frame will be constructed from 2x4s and will be held together with plywood and decking screws. You can either bolt it to the bed rails or tie it down like a slide-on truck camper. If you make a slide-on style camper, you'll need to attach the stilt-jacks to the corners and hang a self-supporting floor as well.
Although your little shed will need to withstand "earthquakes" and "hurricane winds" -- in the form of off-road and freeway driving -- when you think about it, even a simple construction should be able to handle all that, because 1) it's not a skyscraper, but a rather a very short 2-3 foot tall reinforced box, and 2) it's mostly hiding behind the truck cab, so it won't bear the brunt of the highway wind, which can easily be directed over it.
Challenges Of The Cabover
The complex element in a 4WC-style pop-up that may require some skilled engineering is the cantilevered cabover. There's a particular issue that isn't such a big deal in a "hard top", but becomes a special challenge in the 4WC pop-up design. In order to extend the bed area out over the cab, you'll typically want to support it, either from the bottom (as with an angled shelf bracket) or from the top (as with a cable suspension, like your tailgate). But the 4WC design extends the upper bed area on an unsupported (but well-engineered) aluminum cantilever.
This may be less of a big deal if you have a "regular cab" truck, in which case you'd probably only extend the cantilever out about 1-2 feet anyway. But if you have an extended or double cab (which I have), or if you don't mind having the cabover extend over the windshield, then you're talking about a 3-4 foot cantilever -- which no deck inspector would ever allow! (At least using typical "two-by" lumber construction.)
Fortunately, it's doable with wood, and -- unless you were hoping to sleep a whole family up there -- you should be able to accomplish it using clever beam construction (as in "I-beams") without making it too top-heavy. But this is where I can't advise any more than to find an engineer to help you with your particular situation. Constructing cantilevers, especially for non-typical applications like truck campers, is beyond any online calculator or construction table. You need an engineer, even if that means being your own engineer by learning to calculate beam stresses and testing out dozens of beam configurations until you find one that will meet your safety criteria in your chosen worst case scenarios. (Update 9/1: I will say, however that the design I came up with is so strong, I can hang off the edge without any wiggle at all! Details are in my DIY Truck Camper Plans.)
How To Make The Roof
Once you've got the cantilevered cabover licked, the next challenge is the roof. Again, aluminum framing will win the strength-per-weight award, especially if you're thinking you want to be partying on the roof. With wood... maybe not so much. But there are lots of ways to make a lightweight and reasonably stiff frame that will be strong enough to hold -- if not a dance party -- at least some solar panels and maybe a few recumbent stargazers. The basic way is to frame out some 2x3s and 2x2s to support some stiff styrofoam panels topped by painted luan -- the combination is surprisingly sturdy. The top can simply be painted, or if you want to really weatherproof it, you can add a layer of elastomeric rubber coating on top, add your ducting cutouts and seal it all with caulking. (That's typically how camper roofs are made anyway.)
Raising The Roof
As long as you keep the roof light enough and stiff enough, raising it just a bit to get some sun and breeze should be a simple manual job. Even with my first "too heavy" roof, I would often prop up one side by lifting one side of the roof on my shoulders and setting a square of plywood under it. Lifting one side further than about a foot is where it begins to get more complicated, because it will want to slip off the side, so if you enjoy the triangular popup style, you could consider adding hinges to one side.
But in order to lift it further than that or even lift all four corners at once, then you'll really need to look into the popup mechanism. (I also posted a companion article on the Four Wheel Campers roof lifter.)
As far as I'm aware, Four Wheel Campers use two basic styles of roof lifters. The most common type is a patented system that uses hinged plywood levers at either end that push the ends up one at a time at the front and back. There's also a new system by Phoenix Campers, who are the original owners of the Four Wheel Camper name, which opens using a set of bars that push up on the sides rather than the front and back. Though the push mechanism differs in each case, one thing they have in common is that most of the lifting is actually done by a lift assist system, in the form of spring loaded hinges and/or gas springs (struts).
Canvas, vinyl, rip-stop, sil-nylon, mosquito netting... Your choice! Draw up some plans for where you'd like to put the window openings, grab some fabric and zippers (or snaps or velcro if you prefer) from Joann's, and have a crafty friend or your local tailor sew it all together, using a tent for a model for how to do it right. Waterproof it all, and attach to the top rail and the roof with a staple gun. Seal with caulking and test by hosing it all down a bit at a time until you're confident it's all working.
And off you go!
Assuming you've come up with your own preferred solution for the floor, all that's left is to outfit it with necessities. But before you go off and spend thousands on RV appliances, maybe you'd be interested to read about some simple DIY options that may exactly what you need (It links to my section on off grid hackery.)