Jonathan has pretty much said it all but just to add that when I first started I said exactly the same thing "don't care if it cuts slow, just want it accurate."

I have since learnt (and stil learning) that cutting slow is counter productive to accuracy and if you take two small a cut then the cutting edge will skate over and work harden the surface making it harder for the following cutting edge to make the next cut, this then causes the tool to deflect and accuracy goes out the window.

It seems odd but there becomes a point when the cutting force increases as the chip thickness decreases. This is because if the radial depth of cut is small it produces a large shear angle so the cutter sees a large area to cut.

Accuracy is more dependant on the correct material removal rate so you need speed and power.


I seems you have to learn how to build a good machine and then learn how to use it


Jonathan also mentioned aiming for a higher design speed to give headroom on the constant cutting speed but this head room is not wasted as you can have fast rapids when moving between cuts (subject to mass/inertia limitations of course) cut at 5m/min move at 10m/min