Hi Boffingham,
Here's a link to a really ingenious French folding caravan, the Rapido, built
from the 1960s to late 1980s I believe. Some versions even have a kitchen
and porta-potty. This is not like most "folding caravans" that are more like
a popup tent trailer,but with hard walls.
This is a totally folding unit. For travel, the body is @ 34in high by just shy
of 5ft wide and just shy of 8ft long [all real dimensions are metric ya
know] It unfolds to @ 8ft by 11ft8in floor size [didn't notice an opened
interior height measurement].
From what I can see, it is made of what looks like @ 1/2 inch plywood panels
[or maybe something lighter] covered on both sides with some kind
of, possibly, frp sheets with perimeter aluminum extrusions holding them
all together and they also form the interlocking hinging and connecting
hardware.
Here's a Briitish web site on them as an introduction:
http://www.originalrapido.co.uk/
Here's a German individual's web site:
http://www.alfred-johannes.de/06-05-2_rapido_record.htm
Here's a great French web site with great amounts of good info. Look
at all the links within the text and the rest. You can also download a pdf
of an owners manual! - In French, but it's full of great pics.
http://pliante-rapido.com/start.htm
I use Google Chrome as a browser, and it automatically asks if you want
to translate non-English language web sites. Do that, and the info is there
although maybe in a bit of scrambled English - but still plenty usable.
I think looking at these, and really studying the French web site would
really help you in the design and then build.
Hope these are a help.
Cheers,
Norm/mezmo
If you have a house - you have a hobby.