High-Flow Toolhead Engineering

Upgrading a coreXY 3D printer for structural engineering filaments (like Carbon Fiber Nylon, PC, and ASA) requires careful component selection. This field note details the custom toolhead assembly tuned for the DenverNerd 3D printing workshop.

1. Extruder & Cold End Architecture

The toolhead utilizes the Clockwork 2 (CW2) extruder configuration:

  • Drive Gears: Bondtech 50T/10T reduction system
  • Stepper Motor: LDO 36STH20-1004AHG high-temp pancake stepper
  • Filament Sensor: Hall-effect automated runout and jam detection

2. Melt Zone & Hotend: Phaetus Dragon UHF

For volumetric flow rates exceeding 35 mm³/s:

[extruder]
step_pin: can0:PD0
dir_pin: can0:PD1
enable_pin: !can0:PD2
microsteps: 32
rotation_distance: 22.6789511
gear_ratio: 50:10
nozzle_diameter: 0.400
filament_diameter: 1.750
heater_pin: can0:PB13
sensor_type: PT1000
sensor_pin: can0:PA3
min_temp: 0
max_temp: 350
max_extrude_only_distance: 150.0
max_extrude_cross_section: 5

3. Input Shaping Resonance Calibration

To eliminate ghosting artifacts at accelerations above 12,000 mm/s², an ADXL345 accelerometer is mounted directly to the toolhead carriage via CAN bus:

[adxl345]
cs_pin: can0:PB12
spi_software_sclk_pin: can0:PB10
spi_software_mosi_pin: can0:PB11
spi_software_miso_pin: can0:PB2

[resonance_tester]
accel_chip: adxl345
probe_points:
    150, 150, 20

Pro Tip: When printing PA-CF (Nylon Carbon Fiber), keep the passive chamber temperature above 55°C and ensure a hardened steel or tungsten carbide nozzle is installed to resist fiber abrasion.

Download the verified mount STL files and custom toolhead configurations in the DenverNerd Store.