Hi Elf,

The MDX-15's mechanical tolerance is 0.00625 mm/step, maximum table area is 152.4 (X) x 101.6 (Y) x 60.5 (Z) mm.
The scanner tolerance is 0.05mm.
You can mill a variety of materials on it, even soft metals like aluminium & brass, but you wouldn't do metals on a regular basis.
The Spindle motor just hasn't got the power to mill metal on a continuous basis.

It's a great little 3 axis mill as an entry point if you're only just starting out into CAD/CAM with a limited budget or a hobbyist interested in CAD/CAM.
By adding the various attachments from Fourth Axis, you can then move up a level, as your knowledge or budget improves.

Hope this helps, Colin