Power settings are not the same as GRBL

When I try to engrave, either a line or a fill I have to run my power setting at 100%. when running the same in GRBL I can lower it down to like 25% and run at a faster speed. I also do not see Lightburn making any rapid moves between the times the laser is active.
I have a YoraHome 6550 5 watt laser and PC uses Windows 10 Home. I have looked on Youtube for correct settings and have not found anything to help

Hi Mark: Try watching this video and see if it helps: LightBurn Tips - Fixing GRBL Intensity Problems! - YouTube
If you haven’t cleaned your laser lens lately, try that too :slight_smile:

Maybe in firmware you have $30=1000 and in LB you have 255. You know how check this?

I found out how to, thank you very much

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thanks for that video link. it was helpfull

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I’m glad. It didn’t work for me though. Can’t seem to get the power I need to do the job. LaserGRBL works great but I want the extra features in Lightburn.

you aren’t able to use LB with your machine?

Worked on it more this afternoon and finally got results. One thing I still am having issues with is getting the laser to “frame” where it is going to engrave. When I click on “frame” the laser module moves where it is going to engrave but the laser does not “light up” to show the actual engrave frame. Hope this makes sense…

Awesome. Thank you!!!

The most common reason for this is trying to go faster than your laser is allowed to. LaserGRBL uses ‘constant power’ mode by default, which means when the laser is on, it’s on at exactly the power level you ask for, always.

LightBurn uses ‘variable power’ mode by default, which means that the laser goes from 0% power when it is not moving to the power level you ask for when it reaches the requested speed. If you asked for 100% power at 3000 mm/minute, then as the laser accelerates, the power is increased from 0 to 100% as the speed increases from 0 to 3000.

The problem arises when you ask the laser to go faster than the speed limit set in the firmware. If you requested 6000 mm/minute, but your laser had a maximum allowed speed of 3000, you would never reach the requested speed, and therefore you will also not reach the requested power level.

If you ask for 6000mm/sec in LaserGRBL, but your hardware can’t go that fast, it will only go as fast as it is allowed, but by default, it does not ramp the power. You can get identical or better results in LightBurn by simply asking for a speed that is at or less than the speed limit of the machine, because it is pointless to ask it to go any faster.

You can also change the layer to use Constant Power mode in LightBurn, which will mimic the behavior of LaserGRBL. You’ll get burnt spots at the start / stop points of the design, as well as sharp corners, which is why we don’t use this by default.

We have a FAQ entry that covers this here:

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