Optical Filament Runout Sensor

  • $14.95

  • Ex Tax: $14.95

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Optical Filament sensor with LED status indicator.

Simplistic minimalist design for compact size, easily positioned above any hotend extruder to ensure filaments presence! If a break in the filament is detected it signals just like any limit switch with 3 core wiring [With +Voltage, Signal,- Ground: V,S,G wiring output].

  • It was specifically designed with a MINIMAL form factor as the primary design objective, and we believe our design makes this the most compact filament sensor of any type on the market! If any commercially available sensor is shown to us that is smaller we will revise this: however, we have done extensive searches and it was our goal here to create the most simplistic filament sensor possible that also includes a visual indicator (Red Status Led for Runout Signaling) for users to ensure they have it working correctly and to easily see a bright status lite illuminate if filament runout is detected!  - Again please contact us if any smaller sized sensor is available as we believe this to be the smallest design possible that also has a visible indicator for the user, no mechanical switch is required, an IR beam is passed between two points, and a very well placed filament path is certain to abstract or alter the beam (why it is called an OPTICAL sensor), and thus triggering the runout status it if a continuous beam is formed indicating a break in the filament or end of the filament spool! 

    Note: to achieve this high accuracy level for constraining the filament path to perfectly align with the narrow IR beam, we use Genuine Capricorn™ brand High-Quality PTFE tubing to remove any slack between the filament and PTFE tube walls! 

Compatible with any 3D printer board works exactly as a limit switch and is wired exactly the same to an extra limit switch location on your board that you can code to tell the printer to pause ⏸ printing if it is ever triggered. Aso on triggering a Red Light indicator made Clearly Visible by an illuminated frosted column will allow you to easily notice if your printer is in a paused or state that has indicated a filament runout! 

(Not shown in computer renderings is the included JST plug with 3 wire leads coming from it to easily wire to your existing system's wiring, they come with just enough to ensure you are able to solder them to any wires you chose; Approximately 50mm in length. However, we do offer a much better option that will allow you to have a premium solid black round wire with 3 cores for each of the sensor's terminals to run all the way to your control board! in 1M or 2M lengths! Either way, you choose this sensor is ready to go and has all you need to start using it right away!)

3D View 1:

For any wiring, help feel free to contact us!

We run this sensor on many of our Duet 2 Wifi Board machines

Often in tandem with magnetic filament jam or stall detection sensor or any other encoder-based monitor:  As these monitor types are not accurate enough in the sample rates to detect a filament run out before it is too late!!  Leaving the filament too far into the extruder to ever be able to be changed! When it is no longer able to be removed and replaced you are unable to practically replace the filament to continue a perfect print when you have to forcefully dig to try and remove the tiny bit remaining: Defeating the entire purpose of a filament sensor being placed above the extruder! Again which is to catch the filament runout at a state you can still act to change filaments by removing the remaining bit still there!

So please note, even for those with existing filament "Monitors" in most cases, based on where you must mount them to function, they are only useful for stall and jam detection, practically speaking for 99% of the time you need them to be there for (catching Filament Runout - as a far more likely event)  used alone they often cause more trouble than they solve unless used in conjunction with a definite YES / NO Filament Presence detector!  This is even noted by Duet as the P4 & P6 or the "4" and or "6" variable in the M591 Pause Print gcode command for filament sensors/monitors, as seen below:


M591 D0 P4 C3 S1 R70:130 L24.8 E3.0 ; Duet3D rotating magnet sensor for extruder drive 0 is connected to E0 endstop input, enabled, sensitivity 24.8mm.rev, 70% to 130% tolerance, 3mm detection length and is compared with optical or mechanical endstop microswitch.
M591 D0 ; display filament sensor parameters for extruder drive 0

Brief explanation of parameters:

  • Dnn Extruder drive number (0, 1, 2...),
  • Pnn Type of sensor: 0=none, 1=simple sensor (high signal when filament present), 2=simple sensor (low signal when filament present), 3=Duet3D rotating magnet sensor, 4=Duet3D rotating magnet sensor with microswitch, 5 = Duet3D laser sensor, 6 = Duet3D laser sensor with microswitch, 7 = pulse-generating sensor


It is well known for reliable printing an additional sensor is required to avoid the situation described above! Note it is noted as a microswitch in option 6 which we run it in tandem with the magnetic encoder monitor - The optical sensor acts just as a microswitch does (It is identical in terms of its output and used interchangeably). So this issue is recognized by some of the most advanced 3D printer control systems by Duet 3D in the world!

  • Our product is specifically designed to have a minimal form factor so that it can be used alone OR WITH an existing filament monitor to add the certainty, and heads up needed to halt a print even if you have a monitor! Its size makes it perfectly suited to simply be mounted in-line with PTFE tubing above any existing sensors or alone! 

However, we can offer support for any board running marlin firmware! Any board that can wire a limit switch is compatible with this filament sensor! 

Product Version 1.1

*Note Some Ultra Clear Filaments may have issues with detection. 

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