Very cool, but I don't know how one could use the data to calculate a complicated design like my trailer - where the A frame is boxed and welded aluminum plate and channel, with a bolted in steel receiver and 2 inch square steel extendable coupler mount. None of the possibilities match.... so I guess i will have to see if the tongue drops off one day..... then build it stronger.
I bookmarked the website main page anyway - there are lots of interesting plans.
Teardrop and Other Trailer Designs
This fold out motorcycle camper might give you guys some ideas - check the cool animation:
Motorcycle Camper
John Davies
Spokane WA