As explained in previous articles, the software commonly used by K40 laser cutter users is quite limited and does not allow to manage the laser power.
This article will help you to install and set up Lightburn for your K40.
You will be able to manage the power of the laser via your PC, manage the thickness of the materials with your motorized bed, manage a library of materials, getting a fast opening and processing of svg files without common measure with its competitors, advanced functions such as the creation of “tabs” to keep some wood fibers to hold your cuts in place while allowing to detach them easily by a simple pressure, etc…
You can download lightburn here :
The trial version is functional for 1 month and allows ALL the features of the software which will allow you to test it before purchase.
The GRBL license allows the lifetime use of the software as well as its update for 1 year. After this period, it is no longer possible to download new versions but you can continue to use the version you have installed on your computer.
The installation goes without problem, it is not necessary to install the driver which is proposed to you at the end of the installation because it is not used for the Ruida type controllers.
Set up Lightburn
Creation of a laser equipment
At first launch, Lightburn requires you to create / detect a laser cutter.
I advise you to add your laser equipment manually WITHOUT connecting your machine to your PC.
To do this, click on “Create Manually” in the window proposed by Lightburn
Then you have to choose the type of controller.
If you install my Shield, you have to choose “GRBL” then click on “Next”.
There is only one type of interface to connect to GRBL: “Serial/USB”, click on “Next”.
Enter a name for your machine, for my part, I indicated “K40Ava”
Next, you need to enter the working dimensions of your machine.
In general for a K40, you can work on X=300mm and Y=210mm
Enter those values, then click on “Next”
You must then choose the original position for your machine.
On a K40, you must choose “Rear Left” because this is where the machine’s end stops are.
Important: deselect the “Auto Home” especially during the first installation to avoid crashes of your laser head in the various corners of the machine before everything is well adjusted!
Click on “Next”.
Click on “Finish” then “OK”, you now have a laser equipment available in Lightburn.
General parameters of Lightburn
You can access it by clicking on Edit/Settings
These settings are not super important and the default values should be fine for you.
However, you can adjust several Lightburn behaviors to get the most out of it
These parameters are much more important and will impact the operation of your “device”, understand your laser cutter.
At the top left, you can see the size of the working area (300x210mm for a K40) as well as the home position of the machine (the position to which the machine will return after a HOME)
To the right of this block, you can set an XY offset between the visual laser pointer that you can add on your machine (see K40 upgrades) and the real impact of the K40 laser on your material. Why? Because it is almost impossible to correctly center the K40’s laser beam in the head and therefore there is always a mismatch between your visual pointer and the actual impact of the cutting laser beam.
On the right of this block, you will find the management of the Z axis.
If you have integrated a motorized bed like the one of JP Civade (see links in K40 upgrades), you have to click “Enable Z axis” to let Lightburn manage the height of your motorized bed. You also need to click the “optimize Z moves” option to prevent the bed from moving down with each movement of the laser head (this works for a CNC but not for a laser machine)
Below, some options needed to connect and manage the operation of your GRBL controller:
- “Enable DTR signal” must be activated for a correct connection between your computer and the ESP32
- “Enable laser fire button” adds a button to manually fire the laser in the “move” window of lightburn (see main Lightburn interface in the right column)
- “Enable Out of bounds warning” will alert you if you work outside the working area of your machine (this prevents in particular crashes of the laser head at the machine boundary)
- “Return to finish position” allows the laser head to return to the position mentioned here at the end of the work (0,0 to return to HOME position)
- “Air assist” allows you to choose between M7 or M8 to activate the air assist. On my Shield, I connected the air assist on the “M7” command.
- “S-Value MAX” represents the value corresponding to the maximum power of your laser. Leave 1000 as default value
- “Baud rate” represents the connection speed between the computer and the ESP32. You should choose the value 115200 bauds.
- “Transfer mode: leave buffered, this allows the computer to send GCODE lines in advance to the GRBL controller so as not to induce latency in fast movements
In the “GCODE” tab, you can specify GCODE instructions that will be launched before each job start or at the end of the job.
The last tab “Additional settings” is only used to give elements to Lightburn to best estimate the time needed to complete a job
You can ask lightburn to read the settings directly from the controller. But at this point, normally your controller is STILL not connected 😁. You can come back later here.
Machine settings parameters
With FluidNC this page is useless, all the parameters are managed via commands of the type $axes/…
You have the complete list here: http://wiki.fluidnc.com/
Lightburn allows you to set layer parameters for each “layer” of your work.
It is extremely important to always activate the “Constant power mode” option.
End of the installation
At this point, Lightburn is ready to connect to your GRBL ESP32.
However, it is still too early to connect your machine to your computer.
Please read the article on First start of FluidNC ESP32 shield on K40 before connecting K40