Delay after laser off setting

LightBurn is working amazing for me so that being said …
I am doing a manual edit in Vi to add a 70msec delay after any laser power command so that I don’t get these nasty lines leading up to or away from my text or graphics cuts. Is there some setting somewhere to add some number of millisecond delay for each power on or off?

My environment is I have modified my 3D printer with Marlin firmware to use the fan for the pwm to a LASER TREE Laser Module, 10W Optical Power. Yes, hacky BUT works GREAT as long as I edit each gcode file. Is there a setting for pause after any power up or off of the laser? This would save me much complication in my prep of gcode files.

For those curious: Edit the gcode file using the vi editor then use : to get the command prompt at the bottom and use this ‘insanely cryptic command’ which works only on Marlin gcode I think due to their silly usage of non-standard laser power setting commands. BUT this works great if I set LightBurn for Marlin.

So type ‘:’ then use this (70ms shown): g/M106 S[0-9.]*/s//\0 \rG4 P70/g

I hope this both helps others with this issue AND I hope there is some obscure setting to account for cheapo laser DIY response times for hacked etchers like mine. Thanks

At what times do you need the delay? Is it only for first start of the laser, for all changes in power, or something else?

Instead of working around the core issue it may be better if you can address the issue head on. Fan PWM are often very low frequency, lower than ideal for laser control. Do you know what frequency your PWM is set for?

Do you have the option of using a higher frequency pin for PWM? What board are you using? Alternatively, are you able to compile Marlin with fast PWM support?

Along with @berainlb, check if there is a spindle spin up of some type. Sometimes the controller thinks it needs to spin up the spindle before working…

Don’t have a clue in marlin, but I think it’s the $32 value in grbl for laser mode…


Thanks gents for your replies. I have my own workaround and it is not worth it to modify my Marlin code because I have added a 10W laser next to my 3D print head so I use (at different times of course) both 3D printer and etcher. For this reason it is best to just see if there was some config param that every time laser changes power to have LightBurn optionally introduce a delay specified as a custom preferences sort of thing. The answer so far is nobody knows of such an option in Lightburn. I will continue to post-process all gcode files and use the insanely cryptic vi command but that is ok, it is just an extra minute of time. What happens is if I FORGET to do that the etch is bad. So just need to remember it every time. Cheers and thanks again for your thoughts.

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