Good morning all im having a issue with slaow rastering(image) in lightburn ( line works perfect)
Im running lr3 and the latest release of marlin 2.1.1 515 on skr 1.4 turbo , i had lots of support on here to get laser configuration:) , laser turns on via M5 command
My issue is no matter what speed i set raster too the speed stays the same but the power does ajust correctly
If i use the line function the laser also acts correctly with the correct speed and power
Has anyone had this problem also is there a fix ?
Thanks in advance
Luke
The default values for these three settings (defined by V1) are appropriate for using your machine as a CNC router, and take into account the much larger mass being moved around on an MPCNC compared to a 3D printer or a dedicated laser engraver.
Changes to these values can be saved using an M500, but then you would need to change them back when you use your machine as a CNC router. Personally, I change these values in my start g-code define in Lightburn, but I don’t use an M500. This means my machine reverts to the CNC-router-friendly values when the board is powered down.
Note when I made substantial increases in acceleration settings (M201 and M204), I began to get artifacts in my laser movement. See this topic. Some of this inaccuracy might not have translated into a problem for laser raster operations since the movement is in straight lines. And Ryan suggested additional values I might have played with to address the inaccuracy in this post.
If you do increase acceleration substantially, you might want to also play with overscanning values used in your Lightburn layer settings. In addition, you might want to run some tests to see if you need some scanning offset adjustment. Even a small amount of misalignment in the movement between the directions has a large impact on the quality of the resulting image.
For raster you should be well under the firmware limits. I am getting a max of 22-28mm/s for complicated rasters.
How fast are you trying to move?
Raster and lasers are different, your board is trying to do calculations and set your PWM values every ~0.04mm, I have not used your board and you could be experiencing a different sort of bottleneck.
How fast are you trying to move?
That should be turn the laser off. M3 I, turns it on, and inline commands are needed.
In thinking about it, you are certainly right. The firmware limit for XY feedrate is 50mm/s. I know I got substantially faster completion times for raster burns when I increased acceleration, so there should be some headroom there? Or maybe not since raster operations are usually only have acceleration at the beginning or end. I never dialed in my acceleration settings in terms of quality since I ended up purchasing one of the $80 engravers that David suggested, and I’m back to doing only laser cutting on my MPCNC.
Thanks for the reply ryan , for raster i was tryin at 40mms ,but lucky of laser was doing 3 mms , in line i can run around 100mms without issue but when i upload a image and try to engrave the laser slows right down , heres a copy of my M503 settings
You mentioned in line command so possibly on the wrong setting ? As im on M03/M05 (see pic)
If your raster changes shades very much the processor can only handle 22mm/s without stuttering and other issues. Speeding things up only make sit worse.
Move all your speeds down to 20mm/s and start to increase from there.
Yes if you are running
Then you need “inline” not m3/m5. This is certainly the issue.
You also now need to be sure your starting gcode includes “M3 I”
Just to be clear with the speed thing. once you have inline enabled it will move faster but if you feel the steppers they will start to stutter as it moves, to more detailed the more the stutter. If you run something at 15-20mm/s you will feel it running smooth and all the errors and glitches in the etch will go away.
Vector, you can go as fast as your machine can handle before rounding corners.
Yeah switched to inline amd most definitely looks right however not much power coming from laser now ? Ive set to 100% power at 15 mms and still not marking wood or slate , but on m3 instead of inline 40 %is more than enough?
Dig into lightburn a bit I know there is a setting to set the range. It might be 1000, or 255 instead of 100. I am not that familiar but nothing should change the laser power from before.
im having a issue with slaow rastering(image) in lightburn ( line works perfect)
but the power does ajust correctly
