I have a new project that I am putting together. you might be interested in it. I have designed it to cut metal, steel and the like. and it is based on aluminum structure. The project got started in the middle of another machine build more as a proof that the building method is suitable. The goal of this machine is to make an accurate one. as accurate as possible using amateur means, and not breaking the bank. I also want it to have a decent work area. Here are the specs:

Work volume is X 12", Y 6", Z 6"
Round bar rails, with ball trucks.
Precision acme screw, (to start with)

So far I have made the base, which has the x axis rails attached to it. it is made of an aluminum bar 1" x 8" x 14". I milled .030" from the space between the rails to form pads for scraping. I then hand scraped the pads to dead flat. The next step is to mount the rails, and make them true and parallel.

I will upload pictures of the progress shortly.