My first build design: Uno. (Pic heavy!)

[Camp4Life]

Good point rusty... But, like I said, I have all winter to think about it and change my mind 100 times

I thought today about the canvas idea some more. I did a really bad MS paint drawing on my side profile to get an idea what it would look like:

In the image below, the purple line would be the new roof line cutoff. The white part on top is the popup roof, still with vent and fan installed. That black line would be a power cord for the vent fan, and maybe a light or two. The green part I thought would be canvas that wraps around all 4 sides.



But I didn't like the idea of canvas too much. Then I thought about subways and the double-length city busses that have that accordion thing in between, then I thought about an accordion...



I figured, why can't the canvas be replaced with something like this? It can be more rigid, more waterproof, less affected by winds...

So I got a piece of paper and started playing with it to see if I could make it fold up like that.



Success! So, this accordion could be what expands and contracts between the trailer and the popup roof... It would be fairly easy to seal up. And I'm hoping that using a large piece of material would be easier to work with than that tiny little piece of paper. Perhaps some heat applied for the folds, and then all folds reinforced with a layer of some flexible rubberised material...

Or, I wonder if there's such a place where I can order something like this, or get one made for me. It only needs to be less than 2 feet tall, so maybe 5 or 6 folds...

The plot thickens!

[rustytoolss]

very clever

[Dschroeder83]

Cool design! I'm thinking about something like this for a future build. Let us know if you build it

[rustytoolss]

Well I bought a pop up frame today... no turnin back now.

[Fishman Keith]

That's awesome

[Camp4Life]

Thanks guys!

So I'm now on 2 separate paths in the design because I can't make up my mind. For one, I ditched the accordion idea after trying to make a large one out of plastic and using heat to make the folds. It was a disaster.

So I'm continuing on with my previous taller design, but I also have another that's parallel to it. It's shorter, and a popup with a single hinge at the front to raise the roof.

It will be pretty much the opposite of the Cricket trailer seen here:


So mine will be flipped, with the hitch on the other end, and a shorter door at the back instead of the side. I want the whole thing to come down without having to stuff all the canvas back in manually, so I'm working on a few ideas where tabs with eyelets will be glued to the canvas half-way up on the inside. There will be a bracket that is hinged with a bungee cord that will pull in the canvas as the roof is lowered, and the hinge closes. This will let me close the roof while inside when going to sleep, and the canvas will be pulled in by itself.

Here's a really bad pic I did really quick:


So, ahem, to explain said horrible picture above... The blue on top is the roof, and the blue on the side is the wall. So the roof is partially raised. The orange is the canvas. The red lines are the brackets, one is straight, and one is in an L-shape to avoid pinching the canvas when it's pulled in. The brackets are on 3 hinges which are the purple circles. The middle hinge will be spring-loaded so it wants to bend. When you start lowering the roof, the hinge assemble starts folding closed. The attached bungee cord (green line) will then pull in the canvas as the roof lowers. There will be several of these all around so that it all gets tucked in.

That's my only update so far. And other than that, I've been strongly considering putting this on a tandem axle trailer. Not because I'm worried about weight, but because I'm worried about highway blowouts. 1 out of 4 tires blowing out won't be catastrophic.

[KCStudly]

I suspect that you are over engineering the canvas/hinge/bungee/spring design. What you are trying to do has been done before simply with just bungee and separate prop(s). Perhaps the best approach would be to get to the point where the roof and canvas are rough built, then experiment and see. I suspect, with a little care watching the weight of your roof build, that you will be able to lift it easily by hand. Two simple prop rods at the rear and a couple of well placed bungees in the rear corners would probably do the job and work more reliably. Just my $0.02.

I recall (vaguely... not well enough to cite a name) one particular build with a lifting lid that used a bungee loop all around the mid point of the canvas that acted like a cincher.

[Camp4Life]

I suspect that you are over engineering the canvas/hinge/bungee/spring design. What you are trying to do has been done before simply with just bungee and separate prop(s). Perhaps the best approach would be to get to the point where the roof and canvas are rough built, then experiment and see. I suspect, with a little care watching the weight of your roof build, that you will be able to lift it easily by hand. Two simple prop rods at the rear and a couple of well placed bungees in the rear corners would probably do the job and work more reliably. Just my $0.02.

I recall (vaguely... not well enough to cite a name) one particular build with a lifting lid that used a bungee loop all around the mid point of the canvas that acted like a cincher.

Yeah these are just ideas in my head and things can very well change several times during the actual build. There may be prop rods at the back end depending on the weight, as well as a hinged lifting handle (picture the last drawing I posted, but with a handle) to bring the roof up and down, and will lock into place when up.

I really like the idea of the bungee going all around and cinching it in! That's so much simpler and easier to do Might have to go that route. And this is why I post my crazy ideas, because sometimes there's a much easier way to go

[MadMango]

KC is correct. I used to have an '88 Ford Sportsmobile, and the pop-top looked just like this:



Bungee cord (not as thick in diameter as shown in this pic) ran through those rings with just enough tension to pull in the material when the top was lowered (manual via springs) to prevent pinching. 28 years after initial assembly and it still worked flawlessly.

[OP827]

I agree with KC and Madmango. See FYI, it is quite easy to lift a much bigger roof with a simple lever mechanism in front and back -
https://www.youtube.com/watch?v=GcIha16TnF0
Hope it helps with your design.

[MatthewWorks]

Planning to build a pop-top as well... I love that info comes together like this. Simplifying a design is difficult...

Camp4Life - love seeing the design progress, looking forward to seeing it evolve and be built! Thanks for putting it out there.

[Camp4Life]

Thanks guys. Progress on the design will be slow and I may not be on the forum as much. I broke the 2nd knuckle of my ring finger last night so typing is very slow...

The cricket roof isn't unique to that trailer so I don't feel I'm stealing that idea, but I am however going to borrow their idea on how to lift the roof. Have a look



If you look right behind the sink, you can see the two U-shaped bars that are attached together with hinges. When closed, those bars are almost horizontal. You just grab the bar and lift or lower. When it's up, I'll make it so it locks in place with a latch. This will be right above the door since the door is in the middle rear. When you open the door you can raise the roof as you step into the trailer.

[KCStudly]

It looks like the trick is to make the two halves go over center, kind of like a cam or toggle lock. Then the weight of the roof (and any tension in the taut canvas) will more or less hold them locked in the up position (although a quick pin used as a safety feature would definitely be a good idea).

Kind of the same idea as pneumatic hatch struts going over center when closed to help hold the hatch shut.

[Camp4Life]

Yep, just like a toggle lock. I will indeed have some kind of latch or pin to keep it from folding by itself for whatever reason.

[OP827]

This is quite a good video showing how the lifting roof works - https://youtu.be/vm7Q7k3flnk?t=116
It is a gas strut assisted lift and yes, it does a toggle like KC and you've mentioned.

IIRC similar sandwich structure panel of aluminum skinned pvc as skins and XPS foam was discussed on this forum sometime ago by one of the forum members.

And then this same guy designed an even lighter 900lbs smaller trailer with back door and a "porch"- https://youtu.be/sjGq3LqRKv4.
I like how these sandwich panels being made and utilized.