Rotary Setup (Galvo)¶
The Rotary Setup can be found on the toolbar with the rotary icon, in the "Laser Tools" menu near the bottom, or brought up by using Ctrl+Shift+R / Cmd+Shift+R.
To use the rotary with your marking laser, you first need to set up the rotary parameters.
When rotating about the X axis, you'll want to engrave along the X axis (with a resultant scan angle of 0 or 180). When rotating about the Y axis, you'll want to engrave along the Y axis (with a resultant scan angle of 90 or 270).
- First choose whether you have a chuck or roller style rotary.
- Set the 'Steps per Rotation' value to the number of motor steps required to spin the rotary itself one complete rotation when the 'Test' button is pressed. (it should rotate a full 360 degrees, pause, then rotate back to the starting point).
- Set the Min and Max speeds to move the rotary, in pulses per second.
- Set the Acceleration time (the time to ramp the speed from Min to Max speed).
- Set the Return speed value (this value is how fast to move when returning to the starting point)
- Choose whether you are rotating around the X or Y axis. (If the roller is along the horizontal axis, choose X, if it's along the vertical axis, choose Y)
- You may need to enable the 'Reverse Rotary Direction' switch if the output is backwards or sliced in the wrong order.
In most cases, the steps/rotation and other values will be provided by the manufacturer of your machine, either as a screenshot of the rotary params page in EZCAD or a text document.
If you don't know the correct numbers, the 'Test' button in LightBurn will run a single 360 degree movement of the chuck or roller, pause, and return to zero, using the current settings, so it is possible to find usable values by trial and error.
The values listed above, minus object diameter/radius, should only need to be set up once. If the rotary unit or orientation are changed though, performing Rotary Setup again is a good practice.
Galvo markers will run a portion of the job (a slice), rotate the object, run another slice, and so on.
The size of each slice is called the 'Split Size'. If your object is tapered, irregularly shaped, or not perfectly aligned with the rotary axis, using a small split size can help reduce gaps or misalignment of the splits.
A larger split size will reduce the time spent running the job, but can be harder to dial in the settings such that no overlaps or gaps are visible.
To help eliminate visible gaps between slices, you can tell LightBurn to overlap them - specifying an overlap of zero means that each slice is run on its own. A non-zero overlap value will produce that much overlap on the ends of each slice, like this:
If you are removing paint, anodizing, or other surface coating, using a small overlap is recommended. If you are annealing or marking the material directly, adding overlaps could produce visible artifacts.
Run Whole Shapes¶
When 'Run whole shapes, if possible' is turned on, LightBurn will attempt to create splits that keep shapes intact. This can produce a higher quality finish without gaps or misalignment within shapes.
Running the job¶
When rotary mode is enabled, pressing the Start button on the main window will bring up the Rotary Marking window, shown here:
From here you can tune the split size, overlap, and object diameter, as well as jog the rotary, and run the job. When running a rotary job, the center of your page is treated as the current rotary position when you clicked 'Start'. The 'Sanity Check' button will check for some easily overlooked mistakes, and is a good supplement to previewing and framing your design as a final check before running the laser.
This setting allows you to shift the center position of your rotary output to compensate for the center of the rotary not lining up precisely with the center of the field. This value cannot be negative.
This setting is only adjustable (as of 1.2.01) in the Rotary Marking "Run" window, and not the "Framing" window. If you wish to retain use of the Framing dialog, you can set it here, and then use "Frame" all the same.
See Focusing for more information.