Laser cutting 12mm Stainless Steel

[messedup12]

Hi all,

I am pretty new to laser cutting, have only run for 6 months,
my machine is a 4kW Panasonic with lasermech laser head.

I am having some problems cutting 12 mm Stainless steel.

Here are the results:

http://smg.photobucket.com/albums/v327/messeduppieceofshit/Laser cutting problem/

As you can see, the top part is smooth, but the bottom is kinda rough with sharp dross.

I have tried adjusting the speed, but i just cannot seem to find the correct speed.
is there anything else i should try? focus position? gas pressure?

I can cut 10mm stainless just fine btw.

I relly appreciate if someone could help me.

Thank you very much

 

[HenryRollins]

Ok, what are the manufacturer's recommendation for focus, power, feed and gas pressure? What size nozzle/orifice? What is the stand off/nozzle distance? It looks like you were trying to "plasma" cut this material. It could be that you are not getting enough gas pressure (example, cut condition for the machine says you should be using 12 bar but only outputting 8 bar).
-HR

 

[drossfree]

A plasma cut is quite normal for 12mm stainless in my experience, but as henry states your gas pressure is definately too low and would seem to me your focus point is too deep into the material. i cut 12mm, 15mm, and 19mm with a 4000w amada using a 4mm nozzle at 18 bar and a -2.5mm focal point speed for 12mm is 20IPM. speed for 15mm is 14 ipm and for 19mm is 8-10 ipm depending on the day.