# Automatic Pellet Feeding System

# What's in the box

Item Quantity
Pellet Feeding System Controller 1
Air venturi for ¾” hose 1
¾” hose 3.8m
6mm Nylon hose 2m
Worm clamp 3
Elbow PTC 3

# What you need

  • 24VDC Power Supply with a minimum of 2A
  • An open-source compatible 3D Printer Controller (Optional. Enable the printer to pause when you are out of pellets).
    • Marlin
    • Repetier
    • RepRap
  • Compressed air supply
    • An air compressor with a recommended airflow of 50 SCFM or 85 m3/hr (minimum of 10.7 SCFM or 18 m3/hr if using a dedicated compressor)
    • Air filter 10 microns
    • Oil removal Filter
    • Pressure regulator
    • Venturi inlet vacuum hose of 72”H2O or 18 kPa


Our pellet feeding system comes with a corrugated hose designed to withstand vacuum. Should you use another hose, make sure it is rated for vacuum operation.

# Wiring

Front View Terminal Block Detail

  • We recommend using ferrule crimps for the wires of the sensors, power and the output. Ferrule crimps are recommended
  • 24VDC : Connect a 24 DC power supply to the 2 pins terminal block. Positive lead on the left TB
  • SENSOR : Connect the capacitive sensor (packed with your Pulsar™) to the 3 pins terminal block. The DC pins supply power to the sensor from the controller
  • OUTPUT : Connect the output to your control board. If your board uses 24 VDC, jump the power from the Power Supply Terminal block. Otherwise, use the board's voltage. Range : 3VDC - 24VDC

Compressor Input

  • VENTURI : Connect the Venturi Valve to the Pellet Feeding System Controller with Ø6.00 mm or 1/4" OD Hose
  • COMP : Connect the Compressor to the Pellet Feeding System Controller with Ø6.00 mm or 1/4" OD Hose

# Venturi Installation

Check out our drawing page (opens new window) to get the 3D STEP file. Design your bracket according to the available mounting options

Follow the instructions below for a safe installation of the Pellet Feeding System.

  • Position the venturi valve between hoses connecting the hopper/pellets container to the Pulsar Extruder
  • Install ¼” NPT to 6 mm push-in fitting on the venturi vacuum
  • Connect the 6 mm hose between the controller and vacuum
  • Connect the capacitive sensor to the controller
  • Connect the power to the controller
  • Fill the Pulsar™ inlet with material
  • Calibrate the sensor’s sensitivity (see calibration procedure)
  • Connect the hoses to the Pulsar™
  • Connect Air supply to the controller

# Good practices

Good practices

  • Venturi Material Exhaust oriented upward
  • Avoid sharp turns in the hose
  • Material inlet hose oriented upward
  • Material hopper/container converges into a funnel
  • The hose transporting the pellets must have a limited length below the inlet of the bulk material
  • Adjust the open time of the controller according to the length of the hose between the venturi and the pellet extruder.


Avoid any of the details mentionned below!

Bad practices

# Sensor Calibration Procedure

Tools Needed :

  • Small flat screwdriver
  1. Fill the Pulsar™ inlet with pellets
  2. Turn on the pellet feeding controller to power up the sensor
  3. Turn the screw on the sensor counterclockwise until the red LED turns off
  4. Turn the screw a quarter turn clockwise at a time until the red LED turns on

# Pellet Feeding Controller Logic & Configuration

  1. To configure the pellet feeding controller, download & install the venturi configuration tool: VenturyInterface_rev002.msi (opens new window)

  2. Plug a USB mini type B to the controller from your computer and launch the software. You can then configure the operating variables.

  3. Select the COM port your device is connected to. See this page (opens new window) for further information on COM port and drivers

  4. Click Connect

  5. Check the alarm box to turn on the buzzer along the signal. Alarm signal will work regardless

  6. Input the supply “stay on value” in milliseconds. Default is 10000 ms or 10 seconds

  7. Click enter configuration

Plug a USB mini type B to the controller

Configuration inputs

Controller Logic

# Firmware

This section will show you how to enable a pause feature when the venturi controller detects that you are out of pellets and the alarm is raised.

# Marlin Firmware

You can use the filament runout feature.

See our doc: https://docs.dyzedesign.com/filament-sentinel.html#marlin-firmware

# Repetier Firmware

See our doc for filament runout feature: https://docs.dyzedesign.com/filament-sentinel.html#repetier-firmware

# Reprap firmware


# Troubleshooting

There’s a known issue with the firmware on the Pellet Feeding System shipped prior to January 2022.

Behavior : Solenoid valve stays on endlessly regardless of sensor’s state

Fix : Install updated firmware version

# Updating the PFS Controller's Firmware

Requirements :

  1. Connect the arduino to your computer
  2. Launch Xloader
  3. Locate the firmware .hex file
  4. Select the device : Nano(ATmega328)
  5. Select the COM port your device is connected to. See this page (opens new window) for further information on COM port and drivers
  6. Set the Baud rate to 115200
  7. Upload


Last Updated: 5/1/2024, 4:29:37 PM