RedBlueCNC: specs and dimension

Since Concept 3's internal design for the Y and Z axis was working fine, I decided to continue the internal design for the RedBlueCNC (concept 4).

There are 3 main pieces for the box:
1) the top (where most parts attaches to)
2) the bottom (access cover for the mechanics)
3) the tray (not pictured)

Here is the finalized design, about 8" x 6" x 22".  The Z axis will be 18" long as the slides I bought are shorter length.  Each box can technically be as long as the user desires to be easily upgraded.  The top part is proposed to be aluminum extruded.  The bottom part will not be financially feasible to be fabricated out of extruded aluminum so am proposing it to be hand welded since it "would" be a limited scale production.  Ideally a strong plastic extrusion version could be made for entry level CNC or for those not needing stiffness (3d printing, etc). 

Cutting area is about 12" x 12" x 8" depth.  I purposely chose this size as (a) most designers and model makers would be able to do most at this size, (b) keep the size down as most people don't have room for larger tools, and (c) keep costs down for my prototype as I am a student still.  But as mentioned it can technically be lengthened to larger size easily.