Laser Engraver

A complete configuration for laser engraving and cutting machines. Optimized for both CO2 and diode laser setups with safety features.

Machine Specifications

This recipe is designed for:

• 2-axis laser engraver (X, Y movement)
• Laser power control via PWM
• Homing switches for accurate positioning
• Safety features for laser operation
• ESP32 development board

Complete Configuration

name: "Laser Engraver"
board: "ESP32"
version: "3.7"

axes:
  x:
    steps_per_mm: 80.0
    max_rate_mm_per_min: 8000.0
    acceleration_mm_per_sec2: 800.0
    max_travel_mm: 400.0
    soft_limits: true
    homing:
      cycle: 1
      positive_direction: false
      mpos_mm: 0.0
      feed_mm_per_min: 2000.0
      seek_mm_per_min: 4000.0
    motor0:
      step_pin: "gpio.2"
      direction_pin: "gpio.5"
      disable_pin: "gpio.8"
    limit_neg_pin: "gpio.9"

  y:
    steps_per_mm: 80.0
    max_rate_mm_per_min: 8000.0
    acceleration_mm_per_sec2: 800.0
    max_travel_mm: 300.0
    soft_limits: true
    homing:
      cycle: 1
      positive_direction: false
      mpos_mm: 0.0
      feed_mm_per_min: 2000.0
      seek_mm_per_min: 4000.0
    motor0:
      step_pin: "gpio.3"
      direction_pin: "gpio.6"
      disable_pin: "gpio.8"
    limit_neg_pin: "gpio.10"

# Laser configured as spindle
spindle:
  laser:
    output_pin: "gpio.12"
    enable_pin: "gpio.13"
    disable_with_s0: true
    s0_with_disable: true
    tool_num: 0
    speed_map: "0=0% 1000=100%"
    pwm_hz: 5000

# Safety inputs
control:
  safety_door_pin: "gpio.16"
  reset_pin: "gpio.17"
  feed_hold_pin: "gpio.18"

# Air assist
coolant:
  flood_pin: "gpio.20"

Pin Assignment Summary

Function	GPIO Pin	Notes
X Step	2	Step pulse for X motor
Y Step	3	Step pulse for Y motor
X Direction	5	Direction control for X motor
Y Direction	6	Direction control for Y motor
Motor Enable	8	Shared enable for both motors
X Limit	9	X-axis homing switch
Y Limit	10	Y-axis homing switch
Laser PWM	12	Laser power control (0-100%)
Laser Enable	13	Laser enable/safety
Safety Door	16	Lid interlock/emergency
Reset	17	Emergency reset
Feed Hold	18	Pause operation
Air Assist	20	Air pump for cutting

Laser Safety Features

Software Safety

• disable_with_s0: Laser turns off when speed is 0
• s0_with_disable: Speed set to 0 when laser disabled
• Safety door: Immediately stops laser on lid open

Hardware Safety

• Enable pin: Hardware laser disable
• Interlock: Safety door switch
• Emergency stop: Immediate shutdown

Customization Guide

Laser Power Control

PWM Frequency

Different lasers need different frequencies:

• CO2 lasers: 5-20 kHz
• Diode lasers: 1-5 kHz

pwm_hz: 5000  # Adjust for your laser

Power Mapping

Configure power levels:

speed_map: "0=0% 1000=100%"

This maps S1000 in G-code to 100% laser power.

For more control:

speed_map: "0=0% 100=10% 500=50% 1000=100%"

Mechanical Settings

High-Speed Settings

Lasers can move faster than routers:

• Max rate: 8000+ mm/min typical
• Acceleration: 800+ mm/sec² typical
• Jerk: Often higher than milling machines

Belt-Driven Systems

Most laser engravers use belts:

steps_per_mm: 80.0  # GT2 belt with 20-tooth pulley

Different Laser Types

CO2 Laser Configuration

spindle:
  laser:
    output_pin: "gpio.12"
    enable_pin: "gpio.13"
    disable_with_s0: true
    tool_num: 0
    speed_map: "0=0% 1000=100%"
    pwm_hz: 20000  # Higher frequency for CO2

Diode Laser Configuration

spindle:
  laser:
    output_pin: "gpio.12"
    enable_pin: "gpio.13"
    disable_with_s0: true
    tool_num: 0
    speed_map: "0=0% 255=100%"  # Often use 0-255 range
    pwm_hz: 1000  # Lower frequency for diode

G-code Usage

Basic Laser Commands

M3 S500   ; Turn on laser at 50% power
G1 X10 Y10 F1000  ; Cut/engrave move
M5        ; Turn off laser

Engraving Example

G90       ; Absolute positioning
G0 X0 Y0  ; Move to start position
M3 S200   ; Low power for engraving
G1 X50 Y0 F2000    ; Engrave line
G1 X50 Y10         ; Engrave line
G1 X0 Y10          ; Engrave line
G1 X0 Y0           ; Engrave line
M5        ; Turn off laser

Cutting Example

G90       ; Absolute positioning
G0 X5 Y5  ; Move to start position
M3 S800   ; High power for cutting
G1 X45 Y5 F500     ; Cut slow for thick material
G1 X45 Y25         ; Cut line
G1 X5 Y25          ; Cut line
G1 X5 Y5           ; Complete rectangle
M5        ; Turn off laser

Safety Checklist

Before Operation

• ✅ Safety glasses: Appropriate for your laser type
• ✅ Ventilation: Fume extraction working
• ✅ Fire safety: Fire extinguisher accessible
• ✅ Material: Non-toxic, laser-safe material
• ✅ Focus: Laser properly focused

During Operation

• ✅ Never leave unattended: Always supervise operation
• ✅ Monitor progress: Watch for flare-ups or problems
• ✅ Emergency stop: Know how to quickly stop the laser

Interlock Wiring

Wire safety door switch:

Safety Switch NO contacts:
  Pin 1 -> GPIO 16
  Pin 2 -> Ground

Air Assist Setup

Air assist improves cut quality and safety:

Configuration

coolant:
  flood_pin: "gpio.20"  # Air pump control

G-code Control

M8    ; Turn on air assist
M3 S800  ; Start laser
; ... cutting moves ...
M5    ; Stop laser
M9    ; Turn off air assist

Common Issues

Laser Won't Fire

1. Check enable pin: Ensure laser enable is working
2. Verify power: Check PWM signal with multimeter
3. Safety interlocks: Ensure all safety switches closed

Inconsistent Power

1. PWM frequency: Try different frequencies
2. Speed mapping: Verify power levels
3. Power supply: Check laser power supply stability

Poor Cut Quality

1. Focus: Adjust laser focus
2. Speed vs. power: Balance cutting speed and power
3. Air assist: Ensure adequate airflow

Material Guidelines

Safe Materials

• ✅ Wood: Plywood, MDF, hardwoods
• ✅ Acrylic: Cast acrylic (not extruded)
• ✅ Paper/Cardboard: Most paper products
• ✅ Fabric: Cotton, leather (well-ventilated)

NEVER Laser These Materials

• ❌ PVC: Produces toxic chlorine gas
• ❌ Polycarbonate: Produces toxic gases
• ❌ ABS: Produces toxic gases
• ❌ Fiberglass: Glass particles damage laser

Next Steps

• Custom Board Setup - Advanced board configurations
• Expert Editor - Fine-tune settings
• Pin Conflicts - Resolve wiring issues

This configuration provides a safe and effective setup for laser operations. Always prioritize safety when working with lasers! 🔥