I'm not going to use the name "Ghetto CNC Plasma Cutter" since another thread already used that name. However, this project would fit that description for sure.
When I was building new workbenches in my garage, I deliberately built a protruding open top cabinet into the floorspace for the CNC machine to sit on, so I have access to three sides easily enough:
I built the base of the machine out of angle iron, and the uprights out of pre-punched 1" square steel tubing, just to make it easy. Across the top is 1" angle iron to give some structural rigidity:
I made the z-axis first, even though I probably won't need to automate the vertical movement of the plasma cutting torch, but if I ever want this feature now is the time to do it:
And after a few months of 30 minutes here, an hour there, one ends up with a nearly completed CNC plasma cutting system:
If any of you are interested in the full build web page (it's a big page with lots of pictures), it's located here:
http://frederic.midimonkey.com/cnc-gantry2.html
I figured posting a couple of pictures would give an overview of the project, and people interested can click the link for more detail, rather than filling up this post with 150 pictures.