Automated resin material changing system for Anycubic Photon Mono X 6K

A collaborative project between Scion Research and the Massey AgriFood Digital Lab.

This system enables automated multi-material resin 3D printing by coordinating an Anycubic printer with custom stepper-driven pump hardware via a Raspberry Pi controller. Define a recipe of material changes by layer number, and the system handles the rest—pausing the print, swapping materials, and resuming automatically.

• ✅ Automated Material Changes - Define layer-based recipes for seamless material swapping
• ✅ Web-Based Interface - Browser-accessible dashboard, recipe builder, and manual controls
• ✅ Real-Time Monitoring - Live printer status, layer progress, and pump operations
• ✅ Air-Assist Drainage - GPIO-controlled solenoid valve for efficient resin drainage
• ✅ Manual Control Mode - Test pumps, control printer, configure system settings
• ✅ Production Ready - Persistent services, automatic restarts, comprehensive logging

• Raspberry Pi 4 (4GB RAM recommended)
• Anycubic Photon Mono X or compatible resin printer
• Multi-material unit (MMU) with stepper-driven pumps
• I2C motor controllers (Adafruit MotorKit)
• Air solenoid valve for drain assist (optional)

# Clone repository
git clone https://github.com/ScionResearch/multi-material-printer.git
cd multi-material-printer

# Install dependencies
pip3 install -r requirements.txt

# Enable I2C interface (first time only)
sudo raspi-config
# Navigate to: Interface Options → I2C → Enable → Reboot

# Configure system
cp config/network_settings.ini.template config/network_settings.ini
nano config/network_settings.ini  # Set printer IP address

# Start services
chmod +x start_services.sh stop_services.sh
./start_services.sh

Access web interface: http://<raspberry-pi-ip>:5000

1. Create Recipe (Recipe Builder page):

   A,50:B,120:C,200
   

   (Switch to material A at layer 50, B at layer 120, C at layer 200)

2. Start Print on printer touchscreen or via web UI

3. Activate Multi-Material Mode (Dashboard):

   • Click "Begin MM" button
   • System monitors layers and executes material changes automatically

4. Monitor Progress:

   • Real-time status updates on dashboard
   • Material change sequence logged in detail

Comprehensive documentation is available in the docs/ folder:

• Operating Manual - User guide for operators and technicians

  • Safety procedures and emergency protocols
  • Daily operations and multi-material printing
  • Troubleshooting and maintenance schedules

• Programming Manual - Technical documentation for developers

  • System architecture and design principles
  • API reference and WebSocket protocol
  • Development workflow and extension guides

┌─────────── Browser Client ──────────────┐
│  Dashboard │ Recipe Builder │ Manual   │
└──────────────┬──────────────────────────┘
               │ HTTP REST + WebSocket
               ▼
┌─────────── Flask Web App ───────────────┐
│  • HTTP API endpoints                   │
│  • WebSocket server (Socket.IO)         │
│  • Command router                       │
└──────────────┬──────────────────────────┘
               │ WebSocket IPC
               ▼
┌─────────── Print Manager ───────────────┐
│  • Printer status monitoring (4s poll)  │
│  • Recipe execution                     │
│  • Material change orchestration        │
└──────────────┬──────────────────────────┘
               │ Python modules
               ▼
┌─────────── Hardware Modules ────────────┐
│  printer_comms │ mmu_control            │
│  photonmmu_pump │ solenoid_control      │
└──────────────┬──────────────────────────┘
               │ WiFi / I2C / GPIO
               ▼
┌─────────── Physical Hardware ───────────┐
│  • Anycubic Printer (WiFi)              │
│  • Stepper Pumps A/B/C/D (I2C)         │
│  • Air Solenoid Valve (GPIO 22)         │
└──────────────────────────────────────────┘

Design Principles:

• Single hardware authority (only print manager touches hardware)
• Event-driven WebSocket communication
• Persistent background services
• Real-time status updates
• Configurable quiescent windows for safe operation

multi-material-printer/
├── web-app/                    # Flask web application
│   ├── app.py                  # Main server, HTTP API, WebSocket
│   ├── static/                 # JavaScript, CSS
│   └── templates/              # HTML pages
│
├── src/controller/             # Hardware control modules
│   ├── print_manager.py        # Main orchestration service
│   ├── printer_comms.py        # Printer WiFi communication
│   ├── mmu_control.py          # Material change sequences
│   ├── photonmmu_pump.py       # Stepper pump control (I2C)
│   ├── solenoid_control.py     # Air valve control (GPIO)
│   └── websocket_ipc.py        # WebSocket client library
│
├── config/                     # Configuration files
│   ├── network_settings.ini    # Printer IP, port, timeouts
│   ├── pump_profiles.json      # Pump parameters, timing
│   └── recipe.txt              # Current material change recipe
│
├── docs/                       # Documentation
│   ├── OPERATING_MANUAL.md     # User guide
│   └── PROGRAMMING_MANUAL.md   # Developer guide
│
├── start_services.sh           # Start both services
├── stop_services.sh            # Stop both services
├── web_app.log                 # Web app logs
└── print_manager.log           # Print manager logs

[printer]
ip_address = 192.168.4.2
port = 6000
timeout_seconds = 5
polling_interval_seconds = 4

{
  "pumps": {
    "pump_a": {
      "name": "Pump A",
      "flow_rate_ml_per_second": 5.0,
      "max_volume_ml": 200
    }
  },
  "material_change": {
    "quiescence_seconds": 10,
    "bed_raise_time_seconds": 15,
    "drain_volume_ml": 50,
    "fill_volume_ml": 45,
    "settle_time_seconds": 5
  },
  "solenoid": {
    "enabled": true,
    "gpio_pin": 22,
    "activate_before_drain_delay_seconds": 0.5,
    "deactivate_after_drain_delay_seconds": 1.0
  }
}

./start_services.sh

Starts both web app and print manager in background with logging.

./stop_services.sh

Gracefully stops both services.

pgrep -f "app.py"                    # Web app PID
pgrep -f "print_manager.py"          # Print manager PID
tail -f web_app.log print_manager.log  # Monitor logs

# Pull latest code and restart services
ssh pidlp@<raspberry-pi-ip> "cd /home/pidlp/pidlp/multi-material-printer && \
  git stash && \
  git pull origin main && \
  ./stop_services.sh && \
  ./start_services.sh"

cd src/controller
python3 -c "import printer_comms; print(printer_comms.get_status('192.168.4.2'))"

cd src/controller
python3 mmu_control.py A F 5  # Pump A, Forward, 5 seconds

cd src/controller
python3 solenoid_control.py 3  # 3-second test cycle

i2cdetect -y 1
# Should show devices at 0x60 and 0x61

Solution:

# Restart services
./stop_services.sh
./start_services.sh

# Check logs
tail -f web_app.log print_manager.log

Check:

• Printer is powered on
• Printer IP correct in config/network_settings.ini
• Raspberry Pi can reach printer network: ping 192.168.4.2

Check:

• I2C enabled: sudo raspi-config → Interface Options → I2C
• Motor controllers detected: i2cdetect -y 1
• Power supply connected to motor controllers

Check:

• Multi-Material Mode activated (Dashboard shows "Active")
• Recipe saved correctly (Recipe page)
• Current layer detected (Dashboard shows layer number)
• Check logs: grep "MATERIAL" print_manager.log

For detailed troubleshooting, see Operating Manual

Printer Control:

POST /api/printer/pause
POST /api/printer/resume
POST /api/printer/stop

Pump Control:

POST /api/pump
{
  "motor": "A",       # A, B, C, or D
  "direction": "F",   # F = forward, R = reverse
  "duration": 10      # seconds
}

Solenoid Control:

POST /api/solenoid/activate
POST /api/solenoid/deactivate
POST /api/solenoid/test
{
  "duration": 2  # seconds (for test action)
}

Multi-Material:

POST /api/multi-material/start
POST /api/multi-material/stop
GET  /api/recipe
POST /api/recipe

Server → Client:

• status_update - Real-time printer status, material changes, pump operations

Client → Server:

• Handled automatically by UI, see Programming Manual for details

⚠️ Important Safety Information:

• UV resin is a skin and eye irritant - always wear nitrile gloves and safety glasses
• Work in well-ventilated area
• Keep liquids away from electronics
• Do not reach into printer during operation
• Emergency stop button available in Manual Controls page

For complete safety procedures, see Operating Manual

Development:

• Massey AgriFood Digital Lab (MAFDL) - Initial system design and development
• Scion Research - Ongoing development and improvements

Acknowledgments:

• Jean Henri Odendaal - Lead development of initial phases
• Karl Molving - Modifications and ongoing improvements

This project is proprietary to Scion Research and Massey University.

• Documentation:
  • Operating Manual
  • Programming Manual
• Repositories:
  • GitHub Repository
• Organizations:
  • Scion Research
  • Massey AgriFood Digital Lab

Questions or Issues?

For technical support, refer to the troubleshooting sections in the documentation or contact the development team.