eltatertoto,
I saw your vids - cool bike! I feel like that trailer might land you in the hospital though... those angle brackets in the picture already show signs of fatigue. I found a set of blueprints at a free patent searching website that I think you might like to see. It's mostly a metal design, but the "math" has already been done, and it looks like with a dozen or so of the right pipe fittings, you could build the whole thing pretty easily and cheaply. The website is:
http://www.freepatentsonline.com
It's free to make a login - actually free! And you can search for anything - the cross referencing is amazing. Two patents I thought might interest you are:
Des. 414.720 and
US 7,234,719 B2
This is one of my favorite places on the web to just go free-association surfing, well there, and here!!
I love the idea of sinking a loop of chain - one hole in the cement, and it seems like it would be a lot stronger due to the funky shape of the chain in the cement instead of the smooth shape of the U-Lock.
I'm going to do it this weekend - I'll post a picture if anyone wants to see.
Thanks, and seriously, I love what you're doing with that trailer, but be careful! I'm working on a trailer that has a single spherical wheel with no axle! I have to admit I got the idea after seeing I Robot... those Audi's were so sweet! I just ordered a new welder, so I should be able to complete that soon as well...
Thanks for the encouragement everyone! Someone mentioned a few posts back that it was nice to see I hadn't gotten too upset over the loss of my first motored bike. I was upset for about two minutes, then I realized that I was going to build the next one - stronger, faster, better - and sooner! I hope I have at least learned my lesson about locking stuff up! Searching through the patents of bike locks, I found some interesting ideas... once the welder comes, the sky's the limit!