Platform Design

I am looking into building a Root 4 that is of equal size (1500mm ball screws) to the one in the documentation (prime build). The part that I am looking into is the platform the whole thing is placed on. In the prime build welded mild steal was used, I was wondering two things:

  1. How do i determine exactly the size of platform?
  2. What are the thoughts on using like 4040 or 6060 extruded aluminum for the platform?

I also what to using this with a plasma cutter, so that my have impact to the material.

Thank you,
Marshall

Marshall, the platform size just needs to be bigger than the area of the machine. maybe these two links might help;