if you look in the discussion for google sketchup.. someone posted a links to videos for me... i literaly watched these 3 videos and went from not a clue to building my cnc machine in sketchup... there are a few clunky things where you resize one thing and it'll drag the rest of the pieces connected to it in ways you wouldnt imagine.. but simple uses of the group tool, and locking can prevent things like that from happening.

it's got to the point now where i will draw something, and then group it straight away, even if its a piece of box section, you will find out ways to make it work for you.

however.. i aint got a clue how to export it to a cad/cam program and produce a real item from it.. heck i dont even know how to produce a flat piece in to a real item yet