Just to show it can be done - Lego CNC machine.

But I don't think anyone would recommend it! It's great that you picked up the point about adjustability from my other thread but as Jazz says, it's something I learned from this forum. I believe that my machine had an idea or two of my own - don't think I've seen another gantry design where the ballscrew runs through the end uprights, for example - but I'm not entirely sure that I might not have seen that somewhere. I shamelessly picked ideas from many other machines/build logs. That's probably my strongest recommendation.

Remember - copy one person's ideas and that's plagiarism. Copy many people's ideas and that's research!