If you have a Rotary from LightObject or HM Laser Accessories, it should work directly off the board with the built-in drivers. Plug it into the A motor port on LaserBoard, configure, enable and setup in LightBurn. Rotary types/settings will vary and need to be dialed in based on their specifications, but this guide can be used as a general starting point.
Determine Your Steps Per Millimeter
Check your rotary documentation for the needed data. Gather the following information to begin:
- Review the Stepper Motor Specs for the Step Angle and note the corresponding steps per revolution:
- All C3D drivers are set to use 1/16 microstepping. If you are using an alternate external driver for a custom setup, check the driver documentation.
- Determine the reduction ratio of any gear being used on the rotary. Divide the driven gear teeth on the motor by the drive gear teeth on the shaft.
Example: 10 teeth on motor pulley / 20 teeth on shaft = 2:1 Reduction Ratio
- Plug in the previously gathered values:
(Steps per Revolution × Microstep × Reduction) / 360 = Steps per Degree
Example: (200 × 16 × 2) / 360 = 17.77 Steps per Degree
Setup the Config File:
- Power off the C3D Board, remove the SD card and access on your computer using an editor such as Sublime Text. Do not use Notepad++.
- Find the # A axis settings.
- Change the delta_steps_per_mm (Ex: 17.77 calculated previously as Steps per Degree).
- Reduce the delta_max_rate (Ex: 6000 mm/min)
- If needed, increase the delta_current to 0.8 or 1.0. The board’s per driver max is 1.2 amps. Do not exceed the stepper motor max. Ensure the motors are not overheating after increasing.
- Decrease the delta_acceleration to between 50-200. Lower values prevent your work from flying off of the rotary or spinning too fast initially.
- Save your changes, safely eject the SD card, then reinsert into the board and turn everything on.
Test the Rotary
- For roller type rotaries, refer to the rotary documentation or use a micrometer/calipers to measure the actual diameter of the drive wheels in mm.
- Adjust the Rotary settings in LightBurn under Tools > Rotary Setup.
- Select “Chuck” or “Roller” under “Rotary Type”.
- Check “Enable Rotary”.
- Under “Rotary Axis”, select the axis which your rotary is connected to.
- For roller type, enter the previously measured wheel number into the “Roller Diameter”. (Ex: 54.25 mm)
- Enter either the diameter of the object to be engraved or its circumference and the other value will be automatically calculated.
- Click “OK” to save the changes.
- In LightBurn, go to the “Console” tab next to the “Move” & “Cuts” tabs.
- Once the laser connects, type G0 A360 in the command field and hit enter.
- The rotary should now make one full revolution on the wheel. If needed, use a marker to mark the rotary drive gear on the motor and a corresponding mark on the motor bracket to gauge and tweak as necessary.
General information on rotary setup in LightBurn and usage: https://github.com/LightBurnSoftware/Documentation/blob/c486180cfac30f5237872f7e10ec2d463ec3a18a/RotarySetup.md