I've been making lots of progress lately and decided that the time has come to share my results with the forum that's been a great help to me along the way.
My research and parts gathering began in December of '06, but I didn't actually start the build until June 25, 2007.
My gantry is supported and driven from one end and there is some flex I'm working to eliminate. I haven't made the slats yet, but in the meantime, it does work! The little wrench was cut from 10ga. with a standard nozzle, wirebrushed and painted.