I had alot of luck over the weekend with a different basic design for my RP frame. I stripped down a computer chassis and stiffened it up with wood. It seemed like this would be the sort of thing that is easy to find lying arund, older the better too.
I have chosen this path because I wanted to avoid the part count and complexity in building mendels frame. My objective is too build everything short of the electronics with a hand (manual) saw and a drill. I guess that this makes my machine more of a junkbot/repstrap but I'd like to think of it as a reprap with a high count of very simple and easy to find vitamins.
Also I am using some very large gauge model rail road tracks for my guides. They are very inexpensive and I can cut them with some large clippers (and some cursing)