Add Laser Head on Kingroon KP3S 3D Printer

We will show you how to turn your Kingroon KP3S 3D printer into a powerful laser machine, so that you can switch its mode to carve things anytime. And it is quite easy, what you need to do is buying a laser and flashing a new firmware.


Firmware for Laser Head has an Asapter:

KP3S Laser/Printing Firmware(Latest Laser):

KP3S Pro Laser/Printing Firmware(Latest Laser):

KP5M Laser/Printing Firmware(Latest Laser):

KP5L Laser/Printing Firmware(Latest Laser):

Here is the 24V 1.6W laser head we use. 

Kingroon KP3S laser head

Step 1, Connect the Laser on the KP3S Mainboard

First, remove the bottom cover and disconnect the fan cable. 

Then you need to check the MCU of your Kingroon KP3S mainboard, see if it is STM32F103 or GD32F303. The firmware now only works for these two models. We will release a newer firmware compatible for all three MCUs.

Kingroon KP3S mainboard

Connect the laser cable to the HE1 port. You need to remove the white cap of the laser head cable. Don’t mix the negative (black cable) and positive (red cable). This port will be used to power and control the laser.

kingroon kp3s laser head

After that, settle the cables well, put the wrapper back and install the bottom cover. You are ready to proceed next step.

Step 2, Prepare Files

Go visit , download and install the software. Import the files you want to carve, set the right size then save the file.

kingroon laser head

The largest carving size is 150*180mm, just make sure your setting is right. You will get an “NC” file then.

Next, download Kingroon KP3S firmware for laser head. Unzip the file, put everything along with the NC file into your SD card. Check below photo, make sure all listed files are included.

Kingroon KP3S laser head

Step 3, Flash Firmware and Install Laser Head

Put the SD card in your KP3S and power it up. The firmware will start to flash automatically. It will take some time. Once you see the interface, the update is finished.

After that, you will see “Laser mode” and “Print mode” in settings, they are switchable. Switch to “Laser mode”, click “Light on” to test the laser. It should start to shine with an unfocused light.

kingroon kp3s laser head

Then you can install the laser. Remove the print head cover, put screws trough the right-side holes, connect the laser on the right side, make sure the laser is slightly higher than the nozzle.

laser on Kingroon KP3S 3D printer

After that, install the print head cover back, tie the laser cable well.

kingroon kp3s laser head 

Step 4Carving

Now you are all set.  Put a protect board on the heat bed, adjust the print head height manually, aim the object you want to carve, then you can start to carve.

3D Printer laser head

The “Laser mode” won’t auto home, that’s why you need to adjust the carving height and aim the object manually. So, the laser will start to carve from the point you aim, please make sure your file is in a right size and do a well measurement in case it carves over the area. Also, you will get a deeper result by lowing the height.

Here is the result we got. We carved a leaf. 

laser head on kingroon kp3s 

Since the laser are dangerous, please keep it away from your children, wear a protective goggle while it’s carving. Also, if you want to record its carving, you may want to avoid long videos with your smart phone, the shinning lights might damage its COMS.

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Judasc - June 23, 2023

buy this kp3s 3.0 thinking of getting a good upgradeable machine…. kingroon has let customers down using a chip (407) that would never get updates as promised, more than 2 years waiting for the firmware upgrades that the 303 chips got.

Robert - February 25, 2023

Today I received an email from kingroon, a new link to a new firmware that already works! I tried!(kp3s)

Robert - February 25, 2023

Today I received an email from kingroon, a new link to a new firmware that already works! I tried!(kp3s)

CARLOS - February 21, 2023



Jose - February 7, 2023

I installed it with the driver provided, but as soon as the printer is started, the laser is at 100% with the danger that it entails, what is the correct driver for the GD32F303 board model? thank you

Judasc - February 4, 2023

2 years and not 407 support as promised

Dan - January 6, 2023

First, see my previous post on December 25, 2022 (below).
Second, lasers are dangerous if not handled properly.
Third, I do not recommend anybody to follow the steps described here. If you decide to do that, it is at your own responsibility and risk.
I was able to make the laser work using Marlin 2.1.1 by following these steps:
1) Enabling: #define LASER_FEATURE (Configuration_adv.h)
2) Changing laser active state to high: #define SPINDLE_LASER_ACTIVE_STATE HIGH (Configuration_adv.h)
3) Setting the Laser ENA (enabled) Pin to PA1: #define SPINDLE_LASER_ENA_PIN PA1 (Configuration_adv.h)
4) Setting the Laser PWN Pin: #define SPINDLE_LASER_PWM_PIN PA6 (Configuration_adv.h)
With the above settings I am able to control the laser (ON or OFF) using G-code M3/M4/M5 commands. However, I am unable to adjust the laser intensity which makes me suspicious “#define SPINDLE_LASER_PWM_PIN PA6” is incorrect, i.e. the pin for laser power control is not PA6. I tried different pins (e.g. PA3) without success. I was also unable to obtain the schematics and pinout of the laser module that came with the laser.
Please provide the schematic for the laser module, including the pinout.
Thank you

bob - January 6, 2023


Dan - December 25, 2022

I bought the Laser Engraver Head for Kingroon KP3S from website:

I got a different model than the one described in the YouTube video:

The main difference is the laser comes with a Laser module which is supposed to be connected in the in-line driver port, see installation instructions here:

I flashed the laser firmware (ver. 1.0.7):

as described in the YouTube video (see link above) and also described in the website:

The problem is that the laser is always on at 100% intensity. G-code commands such as M5 (spindle/laser off) and M3 S0 (laser on, power 0) do not work, i.e. laser remains at 100%.

Please update the firmware to support this new laser head and share with us.

Thank you

sergikjet - December 19, 2022

Continuation of my sad story.
The laser and its driver board burned out.When you first start working.So don’t be surprised and be ready for it ))).
I ordered a new one- a different kind of it arrived – with a three-pin connector, but without connection instructions))) . The question is where to find the instructions – and will the firmware from kingroon be suitable for the old laser?
Or just throw it out and open a dispute on a refund?)))

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