Comments on my first attempt at a design (if you would)

[hanermo2]

The z axis ratios are way wrong -- as others have said.

You need about 1.5 x width/depth vs height for best results.
Aciera comes to mind.
Deckel.
Schaublin.
About 2x for most commercial machines.

So if you have 600 height you should have 300-400 mm width and depth for best results, and not less than about 250-300 in each dimension.
It´s dirt cheap , relatively.
All modern machines use similar methods with large sections and relatively thin walls around 10 mm.