Creality Filament Runout Sensor Mount for RatRig V-Minion

The RatRig V-Minion does not come with a filament runout sensor.  This mod adds the commonly-available Creality Filament Runout sensor (used on the Ender 3, CR-6, CR-10 series printers) to the V-Minion.  This is a simple switch sensor that allows detection of whether the filament is present or not, and can tell your V-Minion to pause when the filament has run out.

Parts Required for Assembly

1. (4) M3x10 Hex Cap screws
2. (1) M3x30 Hex Cap screw
3. (1) M3 nylon locking nut
4. (2) M3x25 Flat Head screws (comes with the Creality Filament Runout Sensor)
5. (6) M3x4 Heat-Set Inserts
6. (1) M6x6 Heat-Set Insert
7. You will need a soldering iron, ideally with heat-set insert tips, to install the heat-set inserts
8. (1) Reverse-bowden tube mount with an M6 thread
9. 3-wire cable with JST-XT-3 connectors on both ends (comes with the Creality Filament Runout Sensor)
10. You will need the Z-Cap mount from the following shared model, use the version that mounts with the long screw:

https://www.printables.com/model/450862-smart-filament-sensor-z-cap-for-ratrig-v-minion-le/files

Print Settings

The two .stl files are the “MountHousing” and “MountBack”.  They are already oriented for correct printing.  Recommended print settings:

• PLA or PETG
• 15% Infill
• 0.2mm Layer Height
• 0.4mm Nozzle
• No supports necessary

Assembly

1. Print the Mount Housing.
2. Insert (4) M3x4 heat-set inserts into the corner holes.
3. Insert (1) M6x6 heat-set insert into the top hole for the reverse bowden holder
4. Print the Mount Back.
5. Insert (2) M3x4 heat-set inserts into the two holes.  Insert them from the side opposite the mounting lugs.
6. Assemble the Mount Housing and Mount Back together using (4) M3x10 hex cap screws.
7. Slide the Filament Runout Sensor into the housing from the bottom, there is a slot to accommodate the JST connector that protrudes from the left.
8. Secure the Filament Runout Sensor into the housing using (2) M3x25 flat head screws that come with the Filament Runout Sensor.
9. Screw the reverse bowden adapter into M6 insert.
10. Print the Z-cap part from the link above.  Use the version for the long screw.
11. Install the Z-cap part onto your V-Minion according to the given instructions.
12. Mount the assembled Filament Runout Sensor and housing to the Z-cap using (1) M3x30 screw and the M3 nylon locking nut.
13. Plug the wiring harness into the Filament Runout Sensor and into your SKRat mainboard in the E0_DET port.
14. Add the following configuration to your printer.cfg file, and Save and Restart RatOS:

[filament_switch_sensor runout_sensor]
pause_on_runout: true
runout_gcode: PAUSE
#insert_gcode:
switch_pin: !PF4
event_delay: 3.0
pause_delay: 0.5

Verify that the detection is working in your dashboard by inserting and removing filament.

Purchasing Parts

These are some links to these parts, you do not have to use these links, they are only provided as examples.  These are not affiliate links and I have no relationship with the sellers.

Creality Filament Runout Sensor

Heat Set Insert Assortment

Reverse Bowden Tube and Adapter

M3 Screws Assortment

M3 Nylon Lock Nuts

CAD Model File

The FreeCAD model file is provided if you want to modify or remix.  Please see the licensing below.  No commercial use, must re-share your modification or remix.