Is their a general consensus on thickness of aluminum to use for these scratch builds? Angles: Sheets: Exterior walls: Mounting pieces i.e. Drive cage: Corners: Replacement Drive faces: Or is their a one size fits all, say, 1/8th inch thick? I know some prefer to use thicker, but what would the minimum be for those listed above? What kind is best for polished fascia or flexibility? machine-ability? Harder or Softer Aluminum?
Depends very much on the nature of the case and how much equipment is going inside ( weight wise ), and whether you need it to be portable or easy to transport as such. For building a sturdy frame I would use either 1/16" ( 1.5mm ) wall square tubing or 1/8" ( 3mm ) angle generally- so long as it's bolted together well it should be very strong but quite light too. For outer panels and mounting parts ( drive cages, mobo tray ), probably 1/8" again. For decorative pieces like drive faces then thinner stuff is fine, 1/16" of there abouts- some guys use thicker stuff if it it called for asthetics wise, very much depends on your design requirements. If you look at Attila's work then you'll see he uses a wide variety of thickness', anything from 1/16 or 1/32 for decorate internal pieces to hide wiring and such, right upto something like 10mm to form the backbone or skeleton of a case- again, depends very much on the design of the case ( simple box-like structure with simple angles or something much more architectural and open-framed as it were ). I would look at this page to see which grades are best for certain attributes: http://en.wikipedia.org/wiki/Aluminium_alloy Broadly speaking though 6061 & 7075 are used for their strength and machinability- 7075 being the stronger but more pricey ( used in the r/c industry for premium parts, 6061 for normal strength ). I would try to avoid the softer grades really as they dont flex well & bend and dent easily- not a good attribute really. You could do far worse than look at Atilla & Cheapskate's builds to get some ideas...
I found a place in Seattle that sells 1/2" thick 3" wide bars. So I can get a 6' length and then custom make my posts and mill (file) out the shapes.
