It depends what you're doing. For engraving where the machine has to change direction rapidly and regularly you will certainly want more.
Increase the velocity until it just stalls (30*60=1800mm/min seems a bit slow but maybe not as I don't know the mass of your gantry) then back it off by about 10-20% just to be safe. Then increase the acceleration untill it stalls whilst accelerating, and do the same.

Quote Originally Posted by 2e0poz View Post
Note to myself - buy a laptop with a better keyboard, i type faster than it responds
Then change the keyboard layout to Dvorak like I have then you'll be touch-typing faster than it responds...