Best Type of Machine to Build?

[irving2008]

A working area of 600 x 500 will need to be around:

• 800 x 700 as a moving gantry (cutter traverses 600 x 500, need approx 200mm overhangs in both X & Y typically)
• 1400 x 700 fixed X gantry (table moving in X, cutter moving in Y, table 600mm long traverses 1200mm end to end + similar overhangs).
• 1400 x 1200 fixed gantry (cutter stationary, table moving in X & Y, table traverses 1200mm end to end and 1000mm side to side + similar overhangs).

Fixed gantry is more accurate/rigid/responsive if workpiece is relatively lightweight so table & workpiece is lighter weight than router & Y & Z assembly. Arguably easier to construct.

Moving gantry less rigid (and harder to make it so) but takes up less space.

You can (and should) use supported rails for either approach. For fixed gantry the hiwin flat rails make good table runners.