I'm not sure if this counts because it was built for a bike event and was only used once for actual cargo hauling. The trailer is a metal frame made of hand bent 1/2" conduit with the trailer cargo body being made of plywood and various dimensional lumber. Wheels were taken from a 12.5" kids bike. I almost flipped the trailer coming down a hill during the event so it was dismantled shortly thereafter. I'm working on a new cargo trailer that will be more practical. I did win "Best Decorated Bike" at the event the trailer was built for so it could be argued that the utility of the trailer was not in cargo hauling ability but in award winning (the purpose for which it was built).
Me with the bike and trailer
Real men glue plastic rhinestones to their homemade panniers.
During the building stage
and of course I added a "share the road" sticker (complete with LED spotlights shining on it)
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This is a prototype of a hitch design, it was scrapped in favor of a better one for the new trailer in the works.
-Ryan