DIY CNC steel router build part 4.2 - Surfacing the bed! 

Cutting parameters:
Feed - 4500mm/min (175 inches/min)
Speed - 19 000 RPM
Endmill - 6mm 3 flute (for aluminium)
Depth of cut - max 5.5mm (almost 1/4 inch), min 2mm (1/16th)
Stepover - 5.5mm (almost 1/4 inch)