Darkly Labs Community

Cant do different height settings for same job

I like to engrave/Scan my 3 mm MDF with a height setting of 10mm material height for a nice dark even burn.

But If I set to do an engrave/scan with a material height of 10mm (defocussed laser) and then set the cut at 3mm material (actual material height), it reverts the scan back to 3mm or vice versa. they are locked to be the same material height.

So I have to do 2 runs, first the scan set at 10mm height then run the job again with the cut at 3mm, is there a way to be able to have different material/laser heights on the one job? 


Hi Cameron,

At the moment you can only set global values for support height and material thickness.

Being able to set these uniquely per layer is on our wish-list.


To defocus the laser, just use the Z-offset value in the scan / engrave settings for that layer.  Negative numbers are away from the material.

Material height is meant to be just that - If we let you do it per-cut, then if you placed a piece of 6mm ply where you previously used 3mm, you’d have to edit every cut setting, not just the global material setting. By using the Z-Offset value, you’re specifying a delta from the top of the material, so changing one number moves everything up or down.

That makes sense, i will give that a go, thanks

Had a look at this but there is no z offset value for scan, but a few things I noticed.

But I can  choose scan and cut and in the cut-after-scan settings, there is a z offset value there but it DOES NOT work for the scan, ONLY the cut part.

Also, in the cut-after-scan settings, It has number of passes, and this DOES work for the scan bit, which is a plus (it could save me running the scan job multiple times) but still cant adjust offset for unfocussed beam scan.

I think to simplify things, in the cut info part, a z offset and passes bit could go in there. that way there is a super quick way of editing rather than double clicking and having to press ok on every single item of an operation to check their settings, and then a z offset could easily be entered for the scan job.


other things noticed. 

tried to cheat the system and duplicated an item 3 times in the same place to get three passes of a scan but it only does the scan once, yet if I choose cut, it cuts the three items, this is weird. so have to actually run the scan operation 3 separate times to get the result.

to try it, draw 3 separated circles and assign scan (at 2mm interval to make it quick) and run laser and you get 3 scans done, then pick one circle and duplicate it in its spot and run scan, the duplicated circle does not scan. now changed the operation to cut, and you get all plus the duplicated circle cut.)

And…just found by accident that right clicking once on a line in the cuts section makes every item that colour on your screen flash a few times. that is SUPER DUPER AWESOME!!! and makes complicated multi part cut and scan operations soooo much easier to track.



Hi Cameron,

Good points.

Z-Offset on scan would be a good addition, but let’s see what the LB team have to say. There may be a logical reason it was not included.

I will ping the LB team to have a read of this discussion.

Regarding the cheat, here’s why that doesn’t work, visually:

If you want the shapes to scan multiple times, you have to choose “Independent Output”, but that might not do what you want if there are inner curves. LightBurn uses what’s called an odd/even fill rule. Every time the virtual raster crosses a line, it toggles the state from not filling to filling.  If it crosses three lines at the same time, it goes from filling -> not filling -> filling (IE, you only get one fill). Short version: It’s working exactly as designed.

Independent output treats each closed shape as unique, and fills it, but it also has to be smart enough to figure out if shapes are in other shapes, like the middle of an O.  I can add “number of passes” to scans, and that’ll make them do what you want.  That said, I don’t understand why just running it at half or a third the speed won’t do the same thing.

Z-Offset and Pass Count are settings on the whole cut. I need to make one for the scan and another for the cut, so it can apply to either one, and there will need to be a bunch of extra logic added to the GCode generator to inject the right code for them, and handling for the new settings in the undo/redo system, file storage, and cut library.

Regarding your request to add pass count and offset to the Cut Info box, I’ll have to think about that, and maybe test it to see what it looks like. That’s supposed to be dead simple settings, and I’d rather it didn’t get too full or busy.  We have a number of using running tablet-style or other low-res displays on connected machines, and they’re already pushing back on the display size, so I’m hesitant to take more vertical space if I can avoid it.

A better example:
If you drew this, and I scanned the area of the middle circle three times, you’d call that a bug.  :slight_smile:

Intersting read lightburn, thanks for the explanation. SImplest method is usually the best, i will try running scans at a third speed, but if i remember correctly from previois experience, especially with MDF, i could not ever complete the jobs as emblaser kept going to an alarm state with constanst running alarm and had to be switched off.

Since it happenened every time i tried a big job with a slow, nice and dark defocussed engrave, I  put it down to a safety thing with too much smoke in the unit, is that a thing @Domenic, or would this be an alarm for somthing else like laser head getting too hot.


Dont want to load you up with mindless request - but hope to see z offset for scan somewhere and number of passes in the cut ifo bit as this could remove almost all need to even double click and ajust there.

would happily trade the priority bit as that could be adjusted with simple up and down arrow or even drag a cut up or down in the list :wink:

I might do the work of making cut layers draggable within their list, which would remove the need for the visible priority number, and would allow the pass count to be added there. I’ll think about it. Z-offset and pass-count for scans has been requested by others as well, so it’ll likely happen.

No doubt you have a zillion request so greatly appreciate the time in answering


Any progress yet on the unique material height settings per layer?