Andrew/ engineers, what's going on here?

[teardrop_focus]

frank_a

If I understand self-supporting, to do this I would either need to build in outriggers on the existing frame to support the body, or build a self-supporting body right?

The easiest way to think of a teardrop body as self-supporting is to picture a suspension bridge. In my region, the most famous is the Golden Gate bridge...

The walls of the teardrop rest on the chassis' axle area and on the tongue. The Bridge rests on the two towers (an oversimplification, yes).
The floor of the teardrop is supported by the walls as the Bridge's roadway is supported by cables.

[frank_a]

That's a great analogy, thanks! I get it now.

Frank

[bobhenry]

Can I suggest that a self supporting body is any build that can be removed from the frame without loss of form or function.

My very 1st build was a 3x5 motorcycle tear. It was built on a sandwich floor , 2 layers of 7/16 osb glued and screwed into a 2x3 perimeter. Each sheet was set into a rabbeted edge top and bottom. The void was filled with blue foam. 7/16 sidewalls were cut and screwed to the 2x3 perimeter and 2x2 spars were installed. When I was down to this point and it was a completed shell sans roof membrane I easily picked it up and chucked it into the bed of my pickup. Had it been slightly larger I could have camped in just the shell without the trailer frame.

[kennyrayandersen]

BTW, I just wanted to note that you wouldn't need the reinforcement under the tongue if you size it correctly per the design library information. You'd only need that if you needed to beef up a trailer that was undersized or one where you got it from something else and it wasn't strong enough. If you follow the information Andrew has in the design library you shouldn't need it (does look kind of cool, but I'm a weight freak, so no chance on that one...

[angib]

(does look kind of cool, but I'm a weight freak, so no chance on that one...

Hey - does look kind of cool and is very weight-efficient. With a properly designed truss, a decent size teardop could probably use 1"x1" A-frame tubes. The tricky bit is that makes buckling the failure mode and then it all gets very hard to analyse. Except you have probably got access to decent elasto-plastic analysis tools.....

[kennyrayandersen]

(does look kind of cool, but I'm a weight freak, so no chance on that one...

Hey - does look kind of cool and is very weight-efficient. With a properly designed truss, a decent size teardop could probably use 1"x1" A-frame tubes. The tricky bit is that makes buckling the failure mode and then it all gets very hard to analyse. Except you have probably got access to decent elasto-plastic analysis tools.....

Why yes I do! You could get all Maserati birdcage on it, but it would seem a bit 'over-kill' LOL

Having run the numbers on a really lightweight tear, the biggest problem is finding the stock in thin enough gauges! Plus, I'm thinking I'd have trouble welding bike-tube-thick tubes -- I'm just not that good! So a 2 inch square 16 gage tube is plently without the cool looking lower tension truss (Doug H. really ought to consider that on his next work of art!)