5x10 Rigid Pop-Up with Foam

[kipa]

Finished skinning the side walls of the popup. I have not included window supports or cutouts in them at this time. I need to see it be functional before I commit to making my glass fit.

Also got the tonneau lift supports installed and apparently figured the measurements correct in doing so. 50lb struts at all 4 points lifts it well without being overly difficult to pull down. Keeping the tonneau stable without the walls while up is another headache. It fell on me once, but I was able to catch and control it enough to not break or bend anything. Having a second set of hands would help a lot!

Still, I haven't quite got the folding hammered out for hinge attachments. I replaced the low profile strut rail with full height to aid in clearances and beef up the strength a little, but putting it together is definitely a process and a puzzle to get right. At least the straps and temporary support beam keeps it fairly stable.

 

[kipa]

Worked on it all day again. I think the mounting frame for the popup needsa redesign. The structure is good, and I can shake the whole trailer from the roof with it up like this, but without the lower wall hinges installed, it's just strapped on, and not foldable at all yet.

I was hoping to at least get it working for deploying and stowing to take a camping trip for the weekend, but I'll be resorting to a pickup bed tent in my 4x8 utility trailer instead.

 

[louisblanc]

I'm quite interested in this design, with similar considerations for creating less turbulence when towing.

One thing I am still not sure about is how to manage rain in both positions. Do you have particular ideas in mind for handling water?

 

[kipa]

I've given that a fair amount of thought and feel like there is little that EPDM and latex sealant can't address, BUT, in the stowed position, I intend to make sure the tonneau skirting extends to the upper deck of the lower portion. So as long as the seal at the metal rails to the fiberglass is good, that should be easy enough to button up with caulk. I could of course try to build a fiberglass dam against them, but a good caulk is a **** of a lot easier and should last a decade or more before needing replacement.

in the up position, I think a lot can be done by simply covering hinges and exposed areas with vinyl or similar material to shed water away. I have seen other origami builds with that, and it makes sense for being easy and effective.

That leaves the rear access as my biggest concern for sealing. I'll need to have that be 100% reliable stowed since this trailer will sit outside 100% of the time. I haven't rubber stamped my game plan for that yet, but shedding is the first priority, and I will likely end up with some sort of drain channeling to keep it from pooling on the rear deck.

 

[kipa]

Also worth a mention here is that I think the aerodynamic theory on this is working out. I got similar efficiency towing my 4x8 trailer, utility sided and loaded with all sorts of turbulence inducing camping items loaded up to the utility rails, as I did with my last test of this trailer empty.

So obviously it's not going to be MORE efficient, but it seems to validate that the larger shell is not going to hurt if the final design works out.

For my EV6 GT, both drop efficiency to 2.7 mi/kWh from 3.2. So that's well under my 20% range loss goal and just over 15% right now - with more that I can do to clean that up.

 

[kipa]

I have changed approaches on linking the popup with the tonneau for lifting and stability as I wasn't able to get a rigid flat bar to connect from the top to the mid line of the front panel without minor misalignments putting excessive force on the mountings and hinges. So I decided that cables would do the trick just as well since the link only works in tension.

I've only got the one corner done, but I can use this same technique at the rear ends of the sidewalls as well with a single vertical tie, which should solve the issue with the tonneau and sidewalls moving unequally at the rear going up or down and relying on the front connection to carry the entire load.

The extra bit of slack in the cables should ultimately be consumed by filling the gaps with weather stripping at the top mating surfaces.

Fingers are crossed I don't have my physics figured wrong!

 

[kipa]

I am also thinking I may switch the hinges on the 45s to be flat on the outside instead of interior to the joint. Some irregularities in those panels are flexing the hinges in ways that changing the mount position will eliminate.

 

[kipa]

Cables are DEFINITELY the way to go on this. I need to adjust lengths, but nothing is falling apart or down as I work out my clearances.

Shaking it while half way up.

 

[kipa]

I have officially given up on this origami mechanism for now. While it works reliably enough for putting up and down, the fit and security of it stowed just isn't what I want, sitting 6 inches higher than I want it. I can't figure an easy way to fix that without starting from the ground up, so possibly over the next winter that will be something to refine.

For now however, I just want to do some camping!

In that vein, I should be able to knock out the original wedge design in fairly short order. With a fixed pivot at one end, it just doesn't have the same support and stability challenges involved, and I can stick with the cover height while stowed that matches my original road test configuration. Of course I will lose headroom, but it's still very spacious, if barely more headroom than a typical tear/box drop.

The good news is that it's not really much in the way of wasted or unused materials. About 15 square feet of wall (being able to section the sides into wedges for the changed design), two extra lift cylinders, a couple of extra piano hinges, and the support cable hardware are all that will be idled. I have everything else I need to make the wedge work already, so there's that.

 

[kipa]

So much easier to engineer and install!

I was able to use a similar mount system to the original hinge tabs on the tonneau, but I ended up fashioning my own from unistrut 90s facing toward the front on the front strut rail, and angle iron that I slotted to mount on the lower surface of the cover. So if you listen, you can hear some minor clunks as that mechanism shifts going up and down, but it's super stable up or down. (I'm not concerned about the shifting when opening and closing, as that is all 3/16" steel. And combined with the force from the struts and rear anchoring with either a strap or buckle, it's not going to be able to simply fly off while driving.)

Peak height is about 64 inches with the 44" struts, but all setup it will be closer to 56", so no standing up, but plenty of sitting up room for at least me and maybe a friend.

New video · Sunday, Jun 28 ð¬

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[kipa]

New video · Tuesday, Jun 30 ð¬

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[kipa]

Weather sealing progress for the front and sides. I probably overdid the layers of protection on this, but the last thing I want is for water to be forced into the trailer while driving in the rain.

Using 1" EDPM pipe insulation turns out to be a bit of a cheat code for me. A lot of loose tolerances can be filled easily with this stuff and it's nicely compressible. The adhesive that comes on it is actually very good, so no need to use VHB tape.

I used Eternabond Roof Tape, and a bicycle inner tube to seal the front. The lower edge of the rubber is not attached to the shell, so the tonneau remains removable without messing that up. I still need to caulk here and there around the front, but the shedding system is more or less set.

The front and sidewalls of the popup work and seal well open or closed now. I have started construction of the rear wall section and finally ordered a door yesterday, so it won't be much longer before I can actually use this and can focus more on details and finishes.

I have more angle aluminum to install on the exterior tub edges to finish that out. I'm not sure if I will beef up front end protection from road debris, as my car isn't likely to produce any worth worrying about. I will also add a 1/2" plywood panel to the front lower section to protect that from loose objects, though I plan to enclose the first foot with a storage cupboard.

Support sticks on the rear of the sidewalls are temporary and prevent the panels from dropping below 90 degrees folded, which would otherwise stress and damage the hinge attachments.

 

[kipa]

Feeling like I am making good progress now that I gave up on that origami design.

Today, I finished out the diamond plate trim on the upper edge and rear wings. I used Nashua butyl aluminum duct tape to cover seems and gaps in the trim.

I also used leftover foam to add insulation to the tonneau. Great Stuff made it relatively fast to hold and set, though I did have to pick a few of them up and put them back before the latter. Obviously a very imperfect fit, but I intend to cover the whole thing with Reflectix and probably felt. It gets way too hot in the sun not to insulate.

 

[kipa]

I don't think I could engineer a better panel fit with only about 2' of wasted surface area using these Callsun 100W panels.

They are not attached yet, and I will be mounting them on top of 1/2" aluminum tubes running linear to promote airflow on the road and to avoid heat soaking them. (Which is part of the reason my insulation underneath the tonneau is not the most thorough.) Flexible panels have a significant longevity concern regardless, but the Callsuns have a 5 year warranty, so only time will tell if that effort is worth it. Worst case, rigid 100W panels would fit in about the same layout and be less of an aerodynamic concern since they can add power to the system that the additional drag will otherwise waste.

If this works out well, I may add a second rack for panels that extends out the rear to double as an awning when deployed. Total solar would be about 1.2kW peak. We'll have to see how this works out first though.

As expected, the 50 lb. struts I installed are now inadequate to self-raise the cover with the extra 36 lbs. until it's closer to the top of their extension.

I wouldn't worry about adding so much power, but again, this is intended to trail my EV, and being able to travel up to a hundred miles at a time after camping for a week without plugging in is the ultimate goal. (The electric kettle for coffee will always get priority access regardless.) This layout should provide up to 10 miles of recharging per day for me during the summer with good sun, and I don't intend to push 3 season camping very long, nor intend to do any during winter.

 

[kipa]

My rear door idea has changed a bit, opting for a completely removable set of panels.

The door I ordered is specifically narrow enough to be able to fit turned 90 degrees with the cover closed, with my panel sized to fit both vertically for use and horizontal for travel and storage. The side panel(s) will simply be removed and stowed inside.

The width of the door panel is obviously undersized by about 2" in this mockup and will fill and seal the vertical space when turned horizontal.

I am also thinking it would be more ergonomic to raise the threshold of the 23"x44" door to at least 8" high order to minimize ducking and an awkwardly low window when sitting inside. I have not decide if center mounting makes more sense or left mounting. I believe I can have more accessible storage with the center mounting, also providing two cabinet benches on both sides of it instead of one larger bench on the right. A pullout to the rear for kitchen stuff will be on the right side either way.

 

[kipa]

Just for funzies, because I can already feel the difference directly, these are thermal scans after leaving it sitting in direct sunlight until almost noon with the cover closed. (Sorry for lacking thermal color overlay. It was too bright outside to see the screen at all so I was shooting a bit blind.)

It was about 75F at the time, and stepping inside of it wasn't immediately intolerable after opening it. Maybe that will get worse with the top raised though, as the folded in wall panels during stowage likely absorbed and reflected a lot of the heat back into it, and that heat can radiate more into the trailer with it fully open. The finish layers of Reflectix and felt should improve that even more obviously.

An interesting side effect is that I now notice that the cover warps upward about 1/2" with the heat. I'm now wondering if insulating has made that worse by keeping the inside cooler overall, but it also seems to me that heat saturation of the plastic remains the same. Either way, I will need to adjust my upper wall seals to fully mate in the middle now. Worst case, I may end up cutting a very slight convex profile into the top of the sidewalls.

 

[kipa]

Latest thoughts on flexible solar panel mounting:

I have plenty of spare coroplast and 1" XPS, and I am thinking that either one would provide the standoff spacing I want at zero added cost. Pricing out aluminum that's tall enough was just absurdly expensive at up to $250 with 8' long support runners I would need x7. Foam or coroplast is screw down only vs. VHB for aluminum, and getting perfectly straight edges will require a bit more effort. (I have only a handheld hot knife and a good razor knife to work with for the cuts.) Moreover, either material will be less added weight. The coroplast would add less than 5 lbs. stacked to 1", and the foam even less.

Benefits of the coroplast: Less compressible, and more impact resistance and paintable. More difficult to cut by hand.

Benefits of XPS: Lighter and easier to hand cut, less durable and can permanently compress, more limited paint options.

I am leaning toward XPS. Compression concerns can be mostly eliminated by using small pieces of vertical pipe as bushings where the fasteners are. I should be able to crank them down reasonably hard with that.

Perhaps this alone will reduce heat warping of the cover as well.

 

[kipa]

Wow, finally feeling 'right' again after my second shingles shot on Monday. Headache and chills that kept me awake for hours Monday night, followed by significant fatigue all day Tuesday and a 2nd day hangover feeling for much of Wednesday . . so I did NOTHING.

I did however discover that because my trailer is officially just over 80 inches wide that I am required to have a high center brake and marker light. Not a big deal, as I was planning to add one anyway, but that is the first I had heard of it. I doubt I'd ever get stopped for not having it, but ordered one today nonetheless.

Also, my door finally arrived today, so I can get more serious about finishing out the rear. I got it off of Ebay for a fraction of the price others are charging for a similar door. I can't comment on quality comparisons, but it's every bit as good as any RV door I have ever had experience with. I'd buy from that seller again. Pics to follow in the next day or two.

 

[kipa]

New door:

I got my 70lb struts in today, so replaced the 50s with those. With all 6 solar panels just stacked on the rear it is just about perfect for lifting and closing effort.

I also added water skirts to the lower edge of the folding panels. It shouldn't leak after everything else is sealed without them, but the extra insurance never hurts.

 

[kipa]

Not fastened down yet, but I think the rigid foam is the right amount of spacing to keep thermal soak down. Probably going to just series all of them as my inverter can handle up to 150V per input and these panels open circuit are just under 22V. The wire entry gland will be between the two gapped panels.

On another note, don't be tempted to use Liquid Nails, even if you have a tube of it already opened on the shelf to use up. It says "not for plastic" but says it is for wood, yet there I was, 48 hours later scraping it off of the fiberglass plastic panel as it virtually fell off of the luan under it's own weight. I honestly don't understand what that stuff works for . .

I've reglued this panel with non-foaming polyurethane. (The door will be fit into it after curing, which is why no adhesive in the middle.)