Laser GRBL LX4s User manual

Laser GRBL LX4s Controller
User Manual
For use with LightBurn Software

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Copyright information
(c) Copyright 2022 Velocitronics Motion Systems, Inc. (Vms)
The information contained herein is subject to change without notice. The warranties for Vms products and services
are set forth in the express warranty statements accompanying such products and services. Nothing herein should
be construed as constituting an additional warranty.
Trademark credits
Not available at this time
Safety and precautionary information
WARNING: Laser Engravers emit deadly high voltage (20-30kV) and laser radiation
capable of causing instant blindness and tissue damage. Lasers are a fire hazard and a fire
extinguisher must be kept close to the machine at ALL times. Never leave a laser engraver
unattended while in operation!!
The lasing process can emit dangerous toxic fumes which can be deadly. Always operate a laser
engraver in a well-ventilated area or use a fume extractor.
Always wear eye protection that is approved for laser operation for your specific laser while it is
powered on.
When you are ready to install the Laser GRBL LX4s board, disconnect the power cord from the
back of the unit and wait at least 30 minutes before opening or attempting any work on the laser
engraver.

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LX4 Series - Contents
Table of Contents
User Manual................................................................................................................................................................1
Copyright information.............................................................................................................................................2
Trademark credits..................................................................................................................................................2
Safety and precautionary information ....................................................................................................................2
1. About this document.........................................................................................................................................6
Intended audience .................................................................................................................................................6
2. System and Software requirements..................................................................................................................6
Minimum System Requirements............................................................................................................................6
Software Requirements..........................................................................................................................................6
3. Overview of the Hardware ................................................................................................................................7
Board Features......................................................................................................................................................7
Base Board diagram and connector functions........................................................................................................8
Connector definitions and pinout information.........................................................................................................9
Base Board diagram and LED locations ..............................................................................................................10
LED definitions and functions............................................................................................................................... 11
4. Hardware Installation ......................................................................................................................................12
5. Hardware Settings and Software Installation..................................................................................................18
Install the USB driver ...........................................................................................................................................18
LX4s Board power up and Initialization................................................................................................................19
LightBurn Device Setup ....................................................................................................................................... 20
Connecting to the LX4s Board .............................................................................................................................24
Machine Jog X & Y Direction Setup.....................................................................................................................25
X & Y Limit Switch Testing...................................................................................................................................28
Homing Direction Setup and Homing...................................................................................................................30
Workspace Offset Setup......................................................................................................................................32
Steps per mm calibration for X and Y axes..........................................................................................................34
Laser Power Calibration Procedure..................................................................................................................... 35
Rotary Setup and Use.......................................................................................................................................... 37
Z-Bed Setup and Use ..........................................................................................................................................38
Going further........................................................................................................................................................39
Troubleshooting LX4 Board and LightBurn..........................................................................................................40
M7 & M8 Solid State Relay Control Outputs.........................................................................................................41
Laser Power Control Output.................................................................................................................................43
Laser Power Supply and Laser PWM Control Output..........................................................................................43
X, Y & Z Limit Inputs ............................................................................................................................................44
JST XHP Connectors and Part Numbers.............................................................................................................45
JST VHR Connector and Part Number ................................................................................................................46
GRBL Settings and Definitions.............................................................................................................................47
Revision History...................................................................................................................................................50

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1. About this document
Intended audience
This document is intended to be used by individuals who own a K40 or other similar laser engraver and who have
purchased the Laser GRBL LX4s board. This document will guide the user on how to safely install the Laser GRBL
LX4s board into their K40 or similar laser engraver and to help the user get better acquainted with the features and
functions as well as setting up the software and dialing in settings for first time use.
2. System and Software requirements
Minimum System Requirements
• Windows® 7 or later, MAC OS or Linux, 32 or 64 bit
• 8GB or more memory
• Available USB 2.0 or later port
Software Requirements
• LightBurn software (latest Gcode version): Please follow the link for more information, download a
30-day free trial or purchase for $60 USD (recently updated from $40 USD):
https://lightburnsoftware.com/collections/frontpage/products/lightburn-gcode
Link to their GitHub software releases page:
https://github.com/LightBurnSoftware/deployment/releases
LightBurn has tutorials on how to run your first job and many other videos on YouTube as well
as a software support forum here:
https://forum.lightburnsoftware.com/

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3. Overview of the Hardware
Board Features
• 192 MHz ARM Cortex M4 processor with hardware floating point support
• Simple and small board design
• Four axes integrated TMC2208 drivers with access to driver parameters through a grbl setting
• Dual axis Y slave support for Y slave on Z or A axis configurable through a grbl setting
• Z Limit 24V support for industrial sensors such as the Cloudray Z-Axis Focus Sensor
• M7 and M8 24V active low outputs for air assist or external auxiliary control and compatible
with most AC or DC solid state relays
• Electrically isolated full speed USB circuitry for computer to board ground loop isolation
• Custom GRBL firmware loaded with features such as faster step and direction interface, gcode
planner engine, larger serial and planner buffers to handle the high-speed data, 16-bit 1000
step grayscale variable laser PWM output with custom configurable PWM options, Z-enable
homing, all axis freewheel or axis locking ability and laser power maximum control.
• Custom protected free firmware updates. The firmware is field upgradeable through custom
software. The firmware for the processor on the board is proprietary and is not freeware.
Please contact Vms for more information.
Power protection
• 24V power input reverse polarity and surge protection
Low voltage signal protection and filtering
• ALL inputs are ESD protected and low pass filtered. All outputs are ESD protected.

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Base Board diagram and connector functions
Note: Pin 1 is marked with an
❶
❷
❹
❼
❽
❾
❿
❸
❺
❻
⓫
⓬
⓭
⓮
⓯

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Connector definitions and pinout information
Each connector with a┏marker on the board denotes pin 1
1. USB B connector
Pin 1 - +5V power
Pin 2 –Data-
Pin 3 –Data+
Pin 4 –USB Ground
Pin 5 –USB Shield
8. M8 connector
Pin 1 –+24V
Pin 2 –Output
Pin 3 –Ground
2. 24V DC power jack
24V @ 6 amps maximum input
9. Z Limit connector
Pin 1 –+24V Power
Pin 2 –ZL Input
Pin 3 –Ground
3. A-Driver connector
Pin 1 –A-Driver Coil B (B2)
Pin 2 –A-Driver Coil B (B1)
Pin 3 –A-Driver Coil A (A1)
Pin 4 –A-Driver Coil A (A2)
10. X-Driver & XY Limit
Pin 1 –Y-Limit Input Pin 1 –N/C
Pin 2 –N/C Pin 2 –Ground
Pin 3 –+5V power Pin 3 –X-Limit Input
Pin 4 –Y-Limit Input Pin 4 –Y-Limit Input
Pin 5 –X-Limit Input Pin 5 –Ground
Pin 6 –Ground
Pin 7 –Ground
Pin 8 –N/C
Pin 9 –X-Driver Coil A (A2)
Pin 10 –X-Driver Coil A (A1)
Pin 11 –X-Driver Coil B (B1)
Pin 12 –X-Driver Coil B (B2)
4. Z-Driver connector
11. X & Y 3-Pin Limit
X Limit Y Limit
Pin 1 –5V Pin 1 –5V
Pin 2 –Ground Pin 2 - Ground
Pin 3 –X Limit Pin 3 –Y Limit
Pin 1 –Z-Driver Coil B (B2)
Pin 2 –Z-Driver Coil B (B1)
Pin 3 –Z-Driver Coil A (A1)
Pin 4 –Z-Driver Coil A (A2)
5. Y-Driver connector
12. LP Laser Power Adjust
*0–5V variable buffered analog voltage output
Pin 1 –Laser Power Output
Pin 2 –Ground
Pin 1 –Y-Driver Coil B (B2)
Pin 2 –Y-Driver Coil B (B1)
Pin 3 –Y-Driver Coil A (A1)
Pin 4 –Y-Driver Coil A (A2)
6. X-Driver connector
13. AL Laser Output
*Buffered Laser Output is AL (Active-Low) signal
Pin 1 –AL Buffered PWM Output
Pin 2 –Ground
Pin 1 –Y-Driver Coil B (B2)
Pin 2 –Y-Driver Coil B (B1)
Pin 3 –Y-Driver Coil A (A1)
Pin 4 –Y-Driver Coil A (A2)
7. M7 connector
14. LPAL Laser Power & PWM connector
Pin 1 –+24V
Pin 2 –Output
Pin 3 –Ground
Pin 1 –Laser Output
Pin 2 –Laser +5V Power (used for laser output pull up)
Pin 3 –Ground
Pin 4 –Laser +24V Power (not connected)
15. DX Panel Serial Interface
Pin 1 –DX RX Serial Line
Pin 2 –DX Enable
Pin 3 –DX TX Serial Line
Pin 4 - Ground

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Base Board diagram and LED locations
🅐
🅑
🅒
🅓
🅔

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LED definitions and functions
A. Reverse Polarity LED
If the voltage is reversed the red led will
illuminate and prevent the board from
powering up
D
Done/Active LED
This led indicates GRBL is running and
also turns off and on when settings are
updated
B
24V Power LED
If illuminated the 24V power is ON and the
drivers are powered
E
5V Power LED
If illuminated the 5V regulator and
protection switch is working correctly
C
3.3V Power LED
If illuminated the 3.3V regulator and
protection switch is working correctly

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4. Hardware Installation
This procedure is for an M2 Nano controller board replacement in a K40 or other laser engraver. Since there
are many variations of wiring schemes used in different laser engravers this procedure will only cover how to
swap out the M2 Nano board and replace it with the Laser GBRL LX4s board.
1. Disconnect the power cable from the back of the laser engraver. Allow at least thirty minutes for the
power supply capacitors to discharge.
WARNING : Failure to unplug the laser engraver is very dangerous. The laser power supply
operates at 20-30kV and can injure or even cause death. Observe ALL precautions while working near
high voltage electronics.
2. Locate the electronics compartment. For a K40 engraver the electronics compartment is to the right of
the general work area and below the control panel. For other laser engravers consult the user manual to
locate the electronics compartment and open it.
3. Depending on the manufacturer, K40’s generally come in two different formats “ribbon” and “discrete”
cable configurations. The color of the wires is for reference only. As shown on the next page I break up
the three wiring configurations

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“Ribbon cable” configuration 1:
Ribbon
Cable
Contacts
Side

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“Discreet wire”configuration 2:
Ribbon
Cable
Contacts
Side

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“Discrete wire” configuration 3:
Do not use.
Cover
connector
to isolate.

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4. Take note of which configuration you have above and begin by removing the cables from the board. When
the cables are removed you are now ready to remove the M2 Nano frame from the laser engraver.
Pictured here is a K40. If your setup differs from a K40 consult your manual for details on how to remove
your board from your laser engraver. To remove the M2 Nano frame, remove the three screws as shown:
5. Once the M2 Nano board frame is removed, you will need to remove four M4 screws, spacers and nuts
securing the board in place as shown:
❸
❶❷
❶
❸
❷
❹

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6. Once you have removed the M2 Nano board from the frame or other panel, get your new Laser GRBL LX4s
board and fasten it to the same frame or other panel in your laser engraver using the hardware (M4
screws, spacers and nuts) that was previously used to fasten the M2 Nano board. Orientate the board so
that the USB port is facing in the same direction as the M2 Nano board.
The finished assembly for a K40 or other laser engraver should look similar to this:
7. Install your board frame or other panel into your K40 or other laser engraver in reverse
order.
8. Once the mechanical assembly is complete it is now time to install the cables. To install
the cables, follow the “Ribbon cable” or “Discrete wire” configurations previously
mentioned in step 3 of this instruction. Ensure all connectors are securely seated in their
respective locations.
Congratulations the hardware installation is now complete!!
If you did not complete the installation and need further assistance or have questions
regarding the installation, please contact Vms for support.

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5. Hardware Settings and Software Installation
Install the USB driver
1. When you are ready, connect the provided USB cable “A” plug into an available USB 2.0 or USB 3.0 port
on your PC and the cable “B” plug into the Laser GBRL LX4s board. DO NOT connect the power cable
into the board at this time. Below are examples of what an USB “A” plug and “B” plug look like:
2. Once the USB cable is connected you will need to install the CP2102 Driver. Follow the
link below to install the driver. The SiLabs CP2102 works for WINDOWS and MAC.
https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers
Download the one that pertains to your operating system. Follow the instructions on how to install
the driver.
WINDOWS: Once the driver has been installed go to: Device Manager -> expand Ports (COM & LPT) –
The SiLabs com port should show up as shown below. Write down the com port number (for
example: COM5). You will need this later when connecting to LightBurn.
You have now completed the USB driver installation and configuration
🅐
🅑

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LX4s Board power up and Initialization
1. Make sure all connections have been made in section 4. When you are ready, connect the 24V power
supply DC connector to the DC jack on the board FIRST, then connect the AC power cord and then plug
the power cord into the wall outlet. Turn on your laser. The board gets 5V power from the laser power
supply.
NOTE: Depending on the country, the power cord may or may not come with the included power supply.
Please contact Vms for your options if outside the United States.
2. Now observe the led’s. The led’s marked with an arrow should be ON as shown. The board is out of the
enclosure for illustration purposes only. The board is mounted to a K40 panel:
In this example all led’s should be illuminated. If your Laser GBRL LX4s board does not have the led’s
illuminated as shown disconnect power and contact Vms for further assistance.
If steps 1 and 2 are completed successfully you can now move on to the next section.

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LightBurn Device Setup
1. Find and run LightBurn software by double clicking the icon on the desktop or find it in the
start menu. Once open click on Devices button:
2. Once you click on the Devices button you will see a Devices window appear. Since this is a
new installation and there are no devices in the Device List you will need to click on the
Create Manually button as shown:

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3. Once you have clicked on Create Manually button another window will appear. Choose
GRBL-LPC and then Next as shown:
4. Next another window will appear. Click Next as shown:

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5. The next window that appears will ask what you would like to call this connection (you
can leave it as “GRBL-LPC” or you can change it if you choose) and the dimension of the
work area in MM. For a standard K40, enter X = 300mm and Y = 200mm then click Next.
NOTE: If your laser has a bed size that differs from 300mm x 200mm you
will need to change $130 (X-Axis) and $131 (Y-Axis) to suit your bed size.
Please see page 47 for more information.
6. The next window that appears will ask for the origin of the laser (the origin MUST be
Front Left as shown below. Any other option will not work. LightBurn is a positive only
coordinate system). Next turn off Auto “home” your laser on startup for now so we can
setup the jog direction, homing direction and home the machine. This can be turned back
on in the future if you require it. Make the changes as shown below and click Next: