Problem cutting 8mm stainless!

[Michaelhab]

Hi all, some advice please!! Thank you in advance!

A few weeks ago i cut 8mm stainless on our 2.2 kw bystronic, using default settings, and had a brilliant cut - no burrs or anything! I am now trying to cut some again and the cut edge is still brilliant but there are massive (approx 3-5mm long) jagged burs coming of the bottom edge! I have tried everything to remove them with no luck, e.g. cleaned the lens, checked alignment, altered the cut speed, gas, focal point, etc. If anyone can help it would be much appreciated.

I put a sheet of 5mm stainless, and 6mm stainless in and that cut perfectly too (no burrs), but its not cutting the 8mm! Also, the 8mm is the same sheet which i previously cut very well, so it can't be the material!!

The standard settings are.... focal point 8mm, speed 550mm per min, gas 18.5bar, nozzle hk25 2.5mm.

Thanks all,

[Cntkfspac]

umm it can be materials, depends on the grade and quality imperfections in SS aren't that unusual. settings look ok though for that thickness.

cheers

Sam

[Kwmcfsigc]

no 2 materials are always the same. there is going to be differences in the composition each time. frustrating. but likely means you need to play with the settings a little. i haven't done much laser stuff, but im guessing it isnt getting the material hot enough and the gas you are using to blow the slag away is cooling it to fast and it is sticking to the underside of the parts.

[Kkllfoqln]

Do you have a power meter to see if power is degrading? Usually our 2.7k will do that when the lenses are starting to go, or we get a nitrogen problem.