A few thought on lighter foamies.

[rbourne3]

I never finished a build thread, but my weekender is very lightweight. It was built with all torsion box panels, insulated with foam, so I guess it is a semi-foamie. The build pics are on my site, http://thebournes.us/weekender/weekender.html

I didn't get any pics of the trailer, but it is basically Andrews Ultralight chassis made with the harbor freight axle assembly and 1 1/2 box tubing instead of angle for strength. It is just under 500# empty and 750# fully loaded.

[linuxmanxxx]

Ok I've found that what we've called sandwich construction is actually what has been referred to as torsion box construction and is the basis for how aircraft are built and has evolved down to boating, trucking, and many industries for building light and strong.

[loaderman]

Torsion box is a correct term. http://en.wikipedia.org/wiki/Torsion_box
Sandwich construction is a correct term. http://en.wikipedia.org/wiki/Sandwich_theory
and even Stressed Skin Panel http://fmd.ksu.edu.tr/sayi/81/81.60-64.pdf
Monocoque is also a possibility http://en.wikipedia.org/wiki/Monocoque
When using foam you could even say they are SIP's http://en.wikipedia.org/wiki/Structural_insulated_panel

The earliest use of this that I have found is in 1911 in an airplane http://en.wikipedia.org/wiki/Deperdussin_Monocoque

Here is some good information regarding the design and use of them. http://books.google.ca/books?id=G1nSbSA ... el&f=false
http://bulk.resource.org/codes.gov/bsc.ca.gov/sibr/org.apawood.U813.pdf

[loaderman]

RB - love the tow vehichle and the adjustable table leg.

[rbourne3]

The trike weighs less than 1500# so the teardrop has to be light. I want to build a 5 wide, so I'm trying to sell it now. Come to think about it, I didn't list it here. The 5 wide will be a true foamie on a torsion box floor, possibly with torsion axles, to get it even lighter. I'm also 75% done with another trike, so it is for sale also.