You can also use a value greater than 100% if you want to over-burn your image. You can of course use the 100% of your laser or you can set a lower S value if your job is coming out too dark of if you want to preserve your laser lifespan. For more information read the grbl configuration guide. It depends on how your controller is configured. For some the maximum value, which expresses a power of 100% is 1000, for others it is 255. Usually S-MIN it is left set to zero, but you can rise it a little if your laser does not burn under a certain S lever.įor S-MAX you have to express a power level that which is in relation to the max PWM value you set in the grbl configuration. LaserGRBL will use S-MIN for white pixels of the image, and use S-MAX for the black pixels of the image. Power modulation is hardware implemented as PWM modulation on arduino PIN D11, controlled by “S command”. LaserGRBL can process grayscale images to produce power modulated line by line engraving. With S-MIN and with S-MAX you can set the laser power. Otherwise only M3 is available.įor more info, read about laser mode support in grbl v1.1 wiki. M4 is available if LaserGRBL is connected to a grbl v1.1+ machine with Laser Mode option enabled ($32=1). Always do a test piece prior to using this with a new material or machine. In short, this means that dynamic power mode may not work for all situations. Lasers can cut differently at varying power levels and some materials may not cut well at a particular speed and/power. Grbl calculates laser power based on the assumption that laser power is linear with speed and the material. It will generally run faster and may be all you need to use. This is very useful for clean, precise engraving and cutting on simple materials across a large range of G-code generation methods by CAM programs. It essentially ensures the amount of laser energy along a cut is consistent even though the machine may be stopped or actively accelerating. With M3 mode this can cause more severe burns where the laser slows down.ĭynamic laser power mode will automatically adjust laser power based on the current speed relative to the programmed rate. While performing an engraving job, the laser head must constantly accelerate and decelerate to follow direction changes. M4 Dynamic Laser Power Mode (new in grbl v1.1) This can lead to more consistent cuts in more difficult materials.
This provides better control of the laser state. M3 Constant Laser Power ModeĬonstant laser power mode simply keeps the laser power as programmed, regardless if the machine is moving, accelerating, or stopped.
These enable two different laser modes that are advantageous for different reasons each. The laser is enabled with the M3 spindle or M4 spindle commands. (See grbl configuration) 2) Laser options Please note that LaserGRBL will command these values, but it is possible that the machine does not respect them because for example it is limited by its maximum configuration speed. (Is it possible to do little adjustment at runtime via overrides) If your job is coming out too light or too dark you can slow down or increment the requested job speed.