cnc laser machine parameters

[loyedp]

this is loyed . can any person help me to get the right parameters for cutting mild steel 3 mm thickness, as i find melting of mild steel while i cut this one

i am using cnc laser multicam 300 watts machine
and using rofin sc* 30 model laser tube
also use oxygen to cut this

[Laser Pro]

Not being totally familiar with your equipment, I can only recommend the following:

Power @ 300W
Speed to 35-50ipm
Ox pressure to 20-22psi
3.75" fl lense
.020"-.040" diamter gas nozzle orifice.
Set focus just below surface of the material.

[loyedp]

to laser pro

i had a better result when i cut acrylic,but few days before i found some some crack as laser supplie fire for few milli second whille i cut acrylic 6 mm thick sheet,even though it s better few crack are seen in the sides of acrylic sheet. i want some help to get over this problem