2023年1月28日 · 如果激光模式处于活动状态时没有移动，GRBL 不会“按设计”使用 M3/M4 打开激光，这就是为什么您的自定义按钮在需要时（例如）关闭激光模式以打开 LED 进行聚焦。 关闭 barnwellm 打开了这个问题 2020 年 9 月 21 日 · 8条评论 关闭 M3 和 M4 命令#1127 barnwellm 打开了这个问题 2020 年 9 月 21 日 · 8条评论 注释 谷仓 评论了 2020 年 9 月 21 日 我正在运行最新版本的 LaserGbrl，并且发现当我准备好刻录项目时它会继续返回到 M3 命令。

2017年7月26日 · With the M4 code it appears very nice but the laser is switched on too late at some points. The g-code file is about 250kB and it is identical for both tests except the M3/M4 start code. If someone wants it I'm happy to send it. Grbl adjusts the PWM output for the laser based on current speed.

2017年4月27日 · For a spindle, M3 is clockwise rotation, M4 is CCW, and M5 is spindle off. Both M3 and M4 can be used with an S### command to represent spindle RPM. The S parameter can be on the same line, or if M3 or M4 are used alone they will both revert to the last S value.

2021年3月26日 · Agreed GRBL uses M4 at the start to turn the laser On and M5 at the end to turn the laser Off but it also outputs G0 to move with laser turned down (effectivlly Off) and G1 to move with laser at previous high setting (effectivally On). Mach3 does not reconise this so it needs and M3 or M4 On Move and M5 Off Move.

2016年4月2日 · 启用激光模式后，Grbl 通过改变主轴 PWM D11 引脚的 *0-5V* 电压来控制激光功率。

2016年6月7日 · I've been using my mini laser engraver with GRBL 0.9i, so decided to upgrade to version 0.9j. The issue is that now the engraver does not turn the laser on with the M3/M03 command. To turn on the laser now I have to use M4, and M3 to turn off. The M5 command doesn't make any effect.

2023年1月21日 · m4 是动态功率模式，可根据相对于编程速率的当前速度自动调整激光功率。 超级好，但由于激光工作方式的非线性，可能不适用于所有材料。 只会在运动时打开激光。

2021年1月24日 · Laser PWM and M4 dynamic power work correctly with LaserGRBL. LaserWeb has nothing to do with the pin that is used for PWM power. It uses typical laser gcode S value for the laser power. There are two versions of the CNC Shield.

Machines using GRBL 1.1f or later will support the M4 variable power command, and just use the "GRBL" driver in LightBurn. GRBL 1.1e or older (GRBL 1.0, GRBL 0.9, etc) must use the GRBL-M3 device in LightBurn.

M4 is available if LaserGRBL is connected to a grbl v1.1+ machine with Laser Mode option enabled ($32=1). Otherwise only M3 is available. For more info, read about laser mode support in grbl v1.1 wiki. With S-MIN and with S-MAX you can set the laser power. LaserGRBL can process grayscale images to produce power modulated line by line engraving.