Teardrops n Tiny Travel Trailers

Hi to All,
I am looking for advice and assistance with a foam trailer build. Newly registered member but definitely not new to the site. I’ve been browsing and admiring the builds, innovations and insights from everyone here.

I built a small teardrop several years ago and want to improve on what I did. The new build is in the planning stage. It will use foam and the poor man’s fiberglass. I also want to make it a fold-up trailer similar to the Gobur, Esterel, Rapido and Apache that I have seen here and in videos. I have reviewed the vintage Folding Trailer (2mb) plans but I still have some concerns about the build. Done quite a bit of research and have also roamed my limited mind to no avail which brings me to this forum in search of help.

The plan is to build a foamie with 4 folding walls like those mentioned above. The idea is to make this aerodynamic, lightweight and simplistic. It is to be pulled by my motorcycle and will be set-up as a solo occupant build. The trailer dimensions will be 40”W x 80”L x 40”H (+roof) using 1” XPS. The lower walls are to be 22”H and the upper walls 18”H so that the only overlap will be the upper end walls over the upper side walls which will be parallel when closed. The roof will be about 4”H to allow for a deep lip. I understand the lower end walls will need to be offset (taller) than the side walls to allow for closing/folding over the side walls.

My questions are: How do I design the roof and walls to fit when folded in traveling mode and when set-up for sleeping/camping mode? How much offset do I need to plan for in the lower and upper walls builds (wall depth + hinge offset)? Special accommodations for the roof build to allow for proper closed and raised positions to provide a weatherproof seal? Do I need a flap/overlap for the corners and upper walls over lower walls for weatherproofing? Honestly, what I am seeking is a design, drawing or plan that I can preview. I am a visual person and seeing a layout with notes would be very appreciative.

Here is an outline of what I am trying to accomplish.

gallery/image.php?album_id=4962&image_id=157580

FootLoose

A Gobur-style folding foaming is my dream as well. But I want a full size camper. Unfortunately I don't have any plans except in my head.

I'll need to teach myself to use a CAD program. Then make a prototype.

But first I'll have to convince my husband that I'm not crazy. After 35 years together, that might be a hard sell.

I am interested in the possibility of doing something along these lines, only larger, also.

I have no specific advice but I have been collecting youtube videos about designs. Here is the link in case you were interested: https://www.youtube.com/playlist?list=PLJGEPDWX9LjpsdsF-AZqzQlUS2F_Q3cdi. Hopefully it might give you some ideas.

Bill

Maybe make some small ( 1” = 1’ ) models out of scrap cardboard boxes and duct tape …. “see how they Fold “ ???

Thanks everyone,

Appreciate the videos and encouragement. I think I will use some actual material to do a small mock-up as well as using cardboard so I can see the build in 3D and address any concerns with the design and clearances. I look forward to seeing what you come up with on your own projects. I have seen what GPW is capable of ... nice, very nice.

FootLoose

I'm not sure how helpful this is but...

The first side folds in to the floor. The opposite side folds over the the first. To lay flat on top the hinge must be raised up to the thickness of the first side. I wish I were more eloquent. :-(

The top, or roof, of your structure can have an over hanging edge, like a hat box lid, around which the walls fit inside.

I pull my camper with a low powered vehicle like many here so a camper that tows with a low profile and then expands to a useful size is a dream. Curious to see what comes about.

Tt

Tomterrific wrote:I'm not sure how helpful this is but...

The first side folds in to the floor. The opposite side folds over the the first. To lay flat on top the hinge must be raised up to the thickness of the first side. I wish I were more eloquent. :-(

The top, or roof, of your structure can have an over hanging edge, like a hat box lid, around which the walls fit inside.

I pull my camper with a low powered vehicle like many here so a camper that tows with a low profile and then expands to a useful size is a dream. Curious to see what comes about.

Tt

Thanks Tom. Clear enough.

I just need time to tinker with CAD and models. I think I can make it work. All it takes is time (and convincing Z to work on it with me).

The corners will be key. I'm thinking maybe shower door magnets.

Just an idea … wth a folding foamie , maybe you could have Canvas hinges for the big parts … Maybe even coating the hinge area with something like Flex seal or some other "rubberizer” ..

GPW wrote:Just an idea … wth a folding foamie , maybe you could have Canvas hinges for the big parts … Maybe even coating the hinge area with something like Flex seal or some other "rubberizer” ..

Considered that (based on your prior posts). Certainly would be thrifty. But a little concerned that we might get enough moisture into the canvas at the hinge and get rot. Then the whole thing fails. Also considered a living hinge but someone (tony, maybe?) report a failure with that. So now I'm wavering between a continuous hinge (looks) or 3-5 normal door hinges (cheap). Getting either solution to work with a 12' wall section is going to be a challenge.

just a thought … we have the possibility of completely waterproofing a piece of canvas through and through , but not with something like T2 that dries hard , but more with something Acrylic “medium” like I use on painting canvas , which we roll up all the time ( flexible)

I’m just thinking two pieces of fabric sewn together down the middle like the old control surface hinges we used on model planes ...

GPW wrote:just a thought … we have the possibility of completely waterproofing a piece of canvas through and through , but not with something like T2 that dries hard , but more with something Acrylic “medium” like I use on painting canvas , which we roll up all the time ( flexible)

I’m just thinking two pieces of fabric sewn together down the middle like the old control surface hinges we used on model planes ...

GPW: tell me more about the acrylic medium. Like a brand name or something so I can find it. Interesting idea. Do you think it would scale up to a 12' long wall? I'm pretty sure you wouldn't want the seam to be in the middle with the triangular air gaps as shown in the sketch. Maybe move the seam to the inside edge. And give the top and bottom edges just a bit of an angle to encourage water to go down and not in.

Something other than just foam might be required for the wall panel edges so they don't get dinged up. ghcoe's flashing ideas might work. Even have thought of a step profile on the corner edges to prevent water from getting in.

FootLoose: we seem to have highjacked your thread. But hopefully you're getting good ideas from the discussion.

https://www.dickblick.com/products/liqu ... gLVOvD_BwE

We’ve always used it as a varnish , but what it does is seals the canvas fibers to keep water and rot out … Yet the canvas remains flexible …unlike glue which drys hard …. I think the Gripper might work the same way , and is just heavily pigmented … More testing eh? …

And you’re correct about those seams , I was just showing how we joined/hinged two surfaces for planes … but you’re right , just put the sewn middle on the edge of the panel…

For edge reinforcing , we found Common chipboard ( a wood product) really sticks to Foam , and makes it Much stronger, and can be completely waterproofed with "the mix" , making it perform like plywood , without delamination …and lighter weight , and cost too … But plywood would work or even wood strips glued to stressed edges …
George knows all about the edging , he’s done great things with that .. However we used it as a drip edge , and it works Great for that too …

Anybody know what the old timers used ??? We’ll have to look up some older projects , see what they used …

Appreciate the responses & hijacking. It's all about learning for me.

I went back to the cardboard box as suggested and it hit me, , i was trying too hard to understand how the upper walls would work when all I had to do was reverse my own process. Just fold the upper short-length end walls in first then fold the upper long-length side walls which will be side by side just like a cardboard box does, DUH!

I like your idea GPW of the canvas hinges and plan to incorporate it into my build with the sewn hinge offset to the interior side of the wall. It will go nicely with my desire for lightweight and simplicity. The water-sealing does concern me a bit but you gave me some good advice on how to treat it. I have also followed GHCoe's 1st foam build. Have gleaned several good ideas from it, especially with the edging and the hotwire use.

About to begin work on the trailer frame first. Am collecting the material and have a design I am satisfied with. Built the first trailer frame with good success. I plan to post my progress along with pics as I move forward and as time permits for building. This will keep everyone in the loop and allow me to grab free advice as more questions arise.

FootLoose wrote:Just fold the upper short-length end walls in first then fold the upper long-length side walls which will be side by side just like a cardboard box does, DUH!

So just to be clear about what you are thinking - the roof would go straight up, in some way like a pop up trailer roof and then these walls described above would fold up under that?

If so, that seems totally doable and would be awesome really.

Thanks for keeping us posted. I can't wait to see your progress.

Bill

Here is one of the better clips of setting up an esterel camper. Too bad they aren't made any more. Lot to like about NOT dragging a box full of air down the highway.

https://youtu.be/FCNSqn_NUa0

I think they're speaking Dutch and am reasonably certain she says that the set up took 3 minutes.