LaserBoard Diagnostics
Homing or Axes Movement Issues
Homing or Axes Movement Issues
If you are having issues homing your laser or the axes are not moving as expected, please use the following steps to troubleshoot. See the “What to Update” section below for specific scenarios to troubleshoot.
Possible Causes
- Origin not set properly (to front left)
- Not disabling the rotary after use
- Invalid configuration parameters (larger machines or different homing location)
- Stepper motor connectors swapped, inverted, wired improperly, or low current
- Unplugging or plugging in the stepper motor cables while the board is powered on
- Removing or inserting the SD card while the board is powered on
- Powering on the board without the SD card inserted
- SD card not being read properly or corrupt files
- Inductive / Proximity sensors need to be rewired
Overview
The work area is based on the Cartesian coordinate system with (x,y) coordinates. Make sure you are Setting Up the Correct Bed Size, have reviewed and made the recommended Configuration Adjustment Guide changes.
You are telling LightBurn where 0,0 is located in your work area. You can set LightBurn to start at different job origin points or positions and even have it finish in the location you want versus going back to the origin point at (0,0), after a job completes. More information: Coordinates and Job Origin
Note: If you change the device origin in LightBurn, then you also need to change the default settings for homing location in the configuration file. We recommend using the standard setup indicated above.
Check the Setup
- Make sure the Device Origin is set properly.
- Origin differs from the homing location. In LightBurn, Edit > Device Settings and set the ‘Origin’ to the front left (lower) corner.
- The only time this differs is if your setup has endstops / limit switches that are not located or triggered in the rear left corner. You will need to make configuration changes.
- If you have a machine that is larger than 300mm x 200mm, review the Larger Machine Installation Guide.
- If you have inductive / proximity sensors, they will need to be rewired: Installing Endstops / Limit Switches
Check the Wiring
Trace your wires from the motor back to the board and make sure they are making the proper connection.
Based on the specs for your stepper motor, make sure the coil pairs match the pin designations below.
For keyed connectors, they should only allow you to insert in one direction. Depending on the machine, the LaserBoard is typically mounted upside down, so the key may be reversed from what you see on the stock board. This is expected.
How to Test
If your machine is not moving or homing as expected, test your motion control and make notes of each of the results.
Disable Auto Homing:
- In LightBurn’s “Laser” panel click the “Devices” button to get to the device configuration screen.
- Select your laser (most likely named Smoothieware) and click the “Edit” button.
- Click “Next” until you get to the screen where you can turn off Auto home on startup.
- Click “Next” and “Finish” to save the changes.
Test the Movement:
- Turn the power off to disengage the stepper motors.
- Manually move the head to the center of the bed.
- In LightBurn, on the “Move” tab, test the jogging using the arrow buttons to confirm (based on default K40 bed size):
- Left – Moves Left, towards alpha_min (X0)
- Up – Moves Towards the Back, towards beta_max (Y200)
- Right – Moves Right, towards alpha_max (X300)
- Down – Moves To the Front, towards you at beta_min (Y0)
- Home – Machine homes to the location where your endstops / limit switches are triggered
Depending on your results, look at the issues below to determine what steps you need to take. Once you get the movement issues resolved, you can enable auto homing on startup in LightBurn again, if desired.
Note: The endstops must be triggered initially in order for it to know where the head is located at in the work area during navigation. If it seems like your laser head does not know or retain the location, this is why.
What to Update
Power down the machine and control board before making any changes.
Laser Head is Crashing / Endstops Ignored
- Check the values for your configuration file to dial in your settings. If your settings are too fast or the bed size is not valid, it can crash: Configuration Adjustment Guide
- Check the endstops to see if the wiring is making proper contact and that they are triggering as expected. Correct the wiring, make the recommended configuration change (when applicable), or replace faulty endstops, if needed: Testing the Endstops
- If you have inductive / proximity sensors, they will need to be rewired: Installing Endstops / Limit Switches
Origin is Not All The Way to Front
- Update your bed size in LightBurn and in the configuration file: Setting Up the Correct Bed Size
Movement is Backwards / Mirrored
- Make sure the Device Origin is set properly.
- Check the X & Y connectors to see if they are inserted into the correct axis port (not swapped) and are in the correct orientation on the board (not flipped).
- Check the wiring for your stepper motor specifications to make sure your motor pairs are connected in the correct order to the axes headers on the LaserBoard (see the pin designations above).
- As a last resort: If the connector wiring looks good, you may need to invert the direction pin(s) on the config file for the respective axis by removing or appending an exclamation point on the pin value:
alpha_dir_pin 0.5! # Pin for alpha stepper direction beta_dir_pin 0.11! # Pin for beta stepper direction
Only One Axis is Moving
- Make sure the connectors and cables are firmly seated on the board and on the stepper motors.
- Check that all of the pins in your connectors are making proper contact on the board and on the stepper motors.
- For a ribbon cable, make sure the metal contacts are facing inwards, towards the board. The blue strip on the backside of the contacts should face out.
- If you have a rotary switch on your machine or have to swap connections to hook up a rotary, make sure the switch is not enabled and that the wiring has been restored to operate the proper axis.
X Axis is Homing Left, Y Axis is Reversed
- If you have inductive / proximity sensors, they will need to be rewired: Installing Endstops / Limit Switches
Y Axis is Elongated
- Make sure the Enable Rotary option is disabled if you are not running the rotary for the current job.
Stepper Motors Locked on Power Up
- This is usually an indication that the SD card is not inserted, not being read, or the stock files are corrupted (see SD Card section below).
Head is Stuttering or Jerking
- Check the X & Y connectors to see if they are inserted into the correct header (not swapped) and are in the correct orientation on the board. For keyed connectors, they should only allow you to insert in one direction.
- Based on your stepper motor specs, check the configuration to see if there is low current set for using onboard drivers. See External Stepper Driver section below for external drivers.
Skipping or Missing Steps
- If you have Clustering enabled in LightBurn, make sure you are using the proper files for the LaserBoard: Stock Files
- Follow the steps in our Configuration Adjustment Guide.
- If the acceleration is too high, you will get “chattering” on your stepper motors.
- There are three main acceleration settings. One is global and the others axis specific.
- You want the global setting to be the maximum of all three and the other two to be specific for what works best for your machine physics.
- Another common issue is low current set for the stepper motors using onboard drivers. See External Stepper Driver section below for external drivers.
- If the acceleration is too high, you will get “chattering” on your stepper motors.
- Slow down the speed which you are running on the LightBurn layer settings, especially if you are running higher DPI. The limit is determined by how much data needs to be sent to the controller and the speed you are trying to run it at.
- Look for mechanical issues:
- Check for wear and look at the tension on belts; they should touch, but not be too tight.
- Ensure the rails are clean and lubricated.
- Make sure the gantry does not have any slop in it and is square.
- Inspect the idler wheels to make sure they are not misshapen and that there is no debris.
- Check that the pulley grub screws are not loose (if you have the set screw type).
- Move the head around in the area where you are experiencing the issue and compare it to an area where it is running as expected and see if you can noticeably feel any difference in that section of the bed. Inspect problem areas and fix your machine accordingly.
External Stepper Drivers
Install your external drivers per our instructions: Connecting External Drivers
- For configuration changes, follow the steps in our Configuration Adjustment Guide (see separate external driver current info below).
- The default configuration settings are set for 1/16th microstepping. Make sure your external drivers are also set to the same.
- If you change the DIP switches to another microstep setting, then you will have to calculate the steps per mm and update the configuration file accordingly (not recommended). You may also have to dial in some other settings by trial and error to get it to work properly.
- Check the current rating for the stepper motor specs and set your DIP switches according to the current table on the outside of the drivers or in the driver specifications.
- Look at the specs for the external drivers. Check the microseconds_per_step_pulse to determine what it needs to be set at. The default is 2 µs.
- According to the Smoothie site: Step pulse is generally 2 µs above the value (so 1 will actually be 2-3 µs). Setting this over about 8 µs will cause severe issues with step generation, so do not exceed this.
- Ensure you are using a separate 24V power supply to power the external drivers.
- Refer back to the Skipping or Missing Steps section for more info if you experience movement issues after connecting external drivers.
SD Card Testing
Check the SD Card inserted in the board, review the following:
- Ensure the memory card is fully seated into the LaserBoard
- Confirm that the microSD card is installed into the adapter
- Check that the memory card is being read
- Run these tests and reflash the memory card, if needed. Make note of your LED status.
If you are still experiencing issues, do a hard reset on the board and try again.
- Turn the machine off.
- Label and take clear photos of all of the wiring before proceeding.
- Unplug all connectors from the LaserBoard.
- Disconnect the USB and power brick.
- Allow the LaserBoard to sit for a few hours or overnight.
- Reconnect everything.
- Run a test file or command to test.
NOTE: If you have an older version of the controller, alternate troubleshooting steps may apply. Please contact us with photos on the Support Forum for more information.
