Voron 2.4 CW2 Filament Out Sensor

Discussion

Update 25 June 2024

The lower filament path is designed for a PTFE tube with a 3mm ID/4mm OD. Chamfer the end next the gears. This will provide a large target for the filament as it exits the extruder drive gears.

Update V2.6:

In July 2023 the Voron team published a revision to the (a) latch which increased the strength of the latch.  This also affected the motor_plate and main_body.  Both the Filament Sensor and the ECAF versions of the main_body were affected by this change.  Both of these versions that incorporate a filament sensor switch have been updated to reflect the change in (a) latch. All affected parts have been included in the file section in order to insure compatibility.

Update V2.5:

• Removed small obstruction pointed out by Imran_26824,
• Added ECAS latch notched out for ECAS PTFE Connector,
• Added motor_plate from CW2 upgrade.

Initial Release:

This part replaces the original main_body.stl on the stock Voron 2.4R2 CW2 upgrade.  The CW2 is a direct drive filament extruder that supplies filament to the Stealthburner hot end at the rate determined by the slicer software.  It consists of:

1. BMG Extruder Inside parts,
2. NEMA14 36mm Round Pancake Motor/10 tooth gear 20mm,
3. Various ABS printed parts.

The modified part is designed to accept a hartk  or BTT SB2209/SB2240 2-piece Toolhead PCBs.  The normally closed contacts (filament not present) are wired to the FS socket on the main Toolhead board FS and GND terminals.

The configuration files included assume the RPi is running Octoprint or Mainsail, the MCU is an Octopus 1.1 control board, and the print area is 350x350mm.  You will need to update your configuration for the specific setup you have.  The Filament Out Sensor pin for the Octopus 1.1 board is PG13.

The main_body.stl was modified to accept a Bond Tech Push-fit ECAS connector to accept a PTFE filament tube.  This requires less physical space compared to other connector types and easily releases the tube to facilitate filament changes including runout changes.

Included in files section is Filament Out Sensor.txt.  This file contains suggested code to enable the sensor and to provide for filament swaps.  Copy and Paist desired sections into the printer.cfg or use include directive to add the code as a separate file.  If you choose the latter, change the extension from .txt to .cfg.

Add the following code to Octoprint gcode scripts:

After Print Job is Paused

M118 Pausing
CHANGE_FILAMENT

Before print job is resumed

G91
G0 E3
G90

Add the following Octoklipper macros:

Load Filament:

LOAD_FILAMENT

Clean Nozzle:

CLEAN_NOZZLE

Resume:

SET_FILAMENT_SENSOR sensor=fsensor enable=1
CLEAN_NOZZLE
Resume

Use the LCD Unload Filament to back out the filament still in the filament path.  It will be necessary to temporarily remove the PTFE tube from the ECAS connector to manually pull out the filament remnant.

Once the new filament is installed past the extruder pinch gears, use the Klipper macro Load_Filament to load and prime the hotend.  Select Klipper macro Resume to continue printing at the point of interruption.

BOM

See Below: