Create Pause in Fill mode - Material cool down

I have still trouble marking thinner metal sheets with CO2-Laser.
It´s an 60 Watt, KT332N controlled CO2 laser.
Metal sheets should be marked using Cermark Ultra - which works pretty good.

But if I have thinner metall sheets then the sheets heat up and starts deforming, so corners are “coming up” during the engraving process.
This doesn´t happen immediatly, it always took some minutes after the laserjob was started.

Is there an way(option, setting) in Lightburn to add pauses when using fill mode?
So metal sheet can cool down and the inner tension of the material can get lower?

Used settings where:
Air Assist ON
40% power

I made an material test to find these parameters, so reducing the power isn´t an solutions, cause then the marking will be too weak and don´t “stick” on the metal surface.

Maybe doing a pause could also help to avoid thin glass from cracking during engraving process - cause then the thermal stress inside the glas could be reduced also.

Any other ideas how to fix this?

Thank you in advance!

I will append the suggested rates for LBT100, very similar to Cermark. You are running very slow for the suggested speed zone or LBT100…

For stainless and a 45W laser they recommend Stainless Steel 45in/s 60% power. 45in/S is over 1100mm/s… Probably can’t go that fast and I’d bet money it’s much faster than a co2 lps can even respond.

However, saying that I use LBT100 anywhere from 500 to 700mm/s with good results…

I’d try to boost the speed, might have to bump power a bit… You only have to heat a very small area of the Cermark/stainless to bond it…

I also used a slightly lower dpi…

This stuff seems sensitive to both variables, but it’s works well in a very tight range of settings.

I have a 50W that measures 44W…

This is a pdf, remove the .txt extension…

lbt100-settins.pdf.txt (96.0 KB)


Hello Jack,

thank you for the settings.
I doublechecked and they recommend 60in/sec - which is quite too fast for my machine.

More then 500mm/sec isn´t possible at all.

I attached some pictures to make more clear where my problem is.
Looking at them you can see that even the backside of the metal is “deformed”.

Driving the laser fatser needs to increase the power - so in the end I would assume that the deforming of the sheet is similiar.

Thank you,


What kind of maximum speed can you do?

I don’t think you have many options here… Increasing the speed is the only thing I can think of that might help.

Looking at the results… I’m wondering… What is that, a lid to something? Another things is the distortion is massive in some areas compared to the other…

Any chance you could place it on something like a heat sink on the bottom side …


Hello Jack,

this is an cover from a bread box - to take your lunch with you. So the green things is the gasket. (Sorry my english isn´t the best…)

I made another material test with Cermark and an similiar metal sheet (same thickness) - increasing the speed is not the solution:

A heat sink maybe could help - haven´t anything here yet.

So that was the reason why I wonder if it´s possible to add some pause in Lighburn during engraving.
You shortly engrave some lines - make a break, material can cool down, the heat distributes inside the material - and the laser can do the next few passes…

Thanks for your support,

There is not way I know of to delay the execution of the next layer. Others have had this issue also.

It would cut by over half the power adsorbed into the metal by doing 1/2 the lines/inch from what you have now… Don’t know if that would produce reasonable results without the warping…

Don’t really have any reasonable way to fix it, except what I did … order a new laser for metal engraving … you probably don’t want to go down that road… $$


You´re right - in the end this Cermark thing is just an workaround to get CO2 machines engraving metal - so perfect result are not neccessarily to expect.

New machine could be an option - but having limited space here…it was a challenge to get the CO2 machine installed :wink:

Next time I´m gonna try the idea with the heat sink - if it works, gonna let you know.

Have a nice day :slight_smile:

Hello Jack,

did it with an heat sink (an pieces of oldschool black steel) and a bunch of magnets to fix the metal sheet.
Also used some copper paste to have improve heat transfer.

Not perfect - but it works for me that way.

Thank you,


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