Thanks for the links and info Steve.....That article about steering geometry was interesting. Not entirely sure I have wrapped my head around WHY Ackerman angle works, but it totally makes sense how the wheels need to move in different arcs and I found the method for setting it when putting together the front end. So, cool and thanks. Would have never occured to me.
Right now I'm surfing the web for go kart and pedicab parts, collecting ideas and having a lot of fun imagining what I COULD do with parts that I can pretty readily get or make.
Currently I am leaning toward not having a single rear axle at all. Instead I'm thinking the velocar would be two recumbant bicycles with independant rear wheels and gears. They would just share a common steering mechanism. Seems like this way my wife and my pedaling can be completely independant, we can both contribute to the load (at the pavement) at whatever speed and gear that is comfortable....like this guy did
http://www.elkinsdiy.com/mochet-velocycle-pedal-car/
This would all be great. Relatively easy with some free spinning wagon wheels up front and would certainly keep me out of trouble with Johnny Law....However, this is motorbicycling.com, right? What if I put that Northern tool differential axle UP FRONT? With some u joints and steering knuckes, a little harbor freight motor and a CVT driving it....heck, I could even build TWO interchangable front ends, one for pure pedal power and one with the engine on it.
Wouldn't really look anything like it, but let's say "inspired by" this pic
Dreaming is FUN....hoping I can get my stuff together and actually BUILD IT! I know Santa is bringing me a welder. Gotta build SOMETHING with it, right?