Troubleshooting - Output Issues¶
Output is mirrored or backwards¶
- The 'Device Origin' setting, found in the menus under Edit => Device Settings, controls the orientation of what gets sent to your laser. If you have the origin for the device set incorrectly, your output will be mirrored or upside down when run.
- For DSP controllers (Ruida / Trocen / TopWisdom / etc) the Origin setting for the device should match the corner that your laser homes to when first powered.
- For GCode controllers (GRBL, Smoothieware, etc) the Origin is almost always front-left, but in rare cases may not be.
Power output is not the same as other software (GRBL)¶
If you have a GRBL device, there are two possible causes for this:
- You're using 'Variable Power' mode (M4), and asking your machine to travel faster than it is able to. This is the most common problem we see, especially when comparing LaserGRBL output with LightBurn. LightBurn uses 'variable power' mode by default (M4), where LaserGRBL uses 'constant power' mode (M3).
With variable mode, when the laser is stopped, the power level is zero. As the laser head accelerates toward the speed you request, the power level is increased as well. In this way, the output burn is much more consistent. However, if you ask the laser to go faster than it actually can, it will never reach the requested speed, and never reach the requested power level either.
The correct solution is to simply use a speed within the allowed speed range of your machine, or, if you want the same behavior as LaserGRBL, click the 'Constant Power' toggle switch in the layer settings of LightBurn:
- The 'S-value max' setting in LightBurn could be incorrect - this number tells LightBurn which 'S' value corresponds to maximum output for your machine, normally set in the $30 firmware setting. Current versions of GRBL default to 1000 for this setting, while older versions use 255. The number itself doesn't matter much, but the controller setting and LightBurn have to agree. If your controller expects "1000" to mean full power, and LightBurn sends "255", you'll get roughly 1/4 the output power you expect.
Output is shaky or wobbly¶
Output is slanted or skewed¶
Edges of engravings are burnt or too dark¶
On GCode devices, enable 'Overscanning' in your Fill or Image layer setting. If you already have this enabled, you might need a larger value for the overscan setting, particularly if your acceleration is low.
Edges of engravings are fuzzy or blurry¶
First, make sure that your X-axis drive belt is tensioned correctly. If it is loose, you'll see blurred or fuzzy sides when engraving, as well as 'bent' or inaccurate shapes when cutting. If the belt is properly tensioned, you likely need to add scanning offsets.
Corners are not cutting or marking¶
When using a DSP controller, the Min Power setting is also sometimes referred to as 'Corner Power', because it sets the power level of the laser when the machine is moving slowly, like when cutting a sharp corner. if your Min Power value is too low, when the laser slows for corners the power value might fall below the firing threshold of your laser. This will leave gaps in the output at the corners, and at the points where cuts start and stop. Increase the Min Power value.
Corners are burnt or too dark¶
Similar to the above, if the Min Power setting is too high, the power value may not be reduced enough when the laser slows for corners, and can leave burn marks at corner points or the start / stop points of the design. If this is happening, reduce the Min Power setting.
Laser is losing power / not cutting at low speeds¶
On DSP controllers, If you are running a cut at very low speed, set your Min Power and Max Power values to match.
There is a setting in the Machine Settings, called 'Start Speed', that specifies the value where the controller begins ramping the power from Min to Max power. If the laser is moving at this speed or slower, only Min Power is used. This setting is 10mm/sec by default on Ruida controllers, but some machines may have it set as high as 15 to 20 mm/sec, or may have it set lower.