Filament sensor troubleshooting

Owned by Imagine That
Jan 13, 2023
1 min read

Please follow these steps if the filament sentinel sensors are not working as expected.

General sensor function check

With the machine on, please use the green LEDs on the filament sensor body to check the function.  They work in the following manner:

Filament present: Green LED is ON

Filament absent: Green LED is OFF

To test, insert filament and confirm the green LED is lit.  Remove the filament and confirm the green LED turns off.

Startup script check (may correct false negatives)

Please ensure the following line is present in your slicer's custom start g-code to avoid false negatives.  This line is necessary to setup the filament sensor function:

  1. M98 P/sys/start.g

Filament load check (may correct false positives)

Please ensure that when running a print, both sensors have material loaded to avoid false positives (unwanted filament change triggers).  This is necessary even when running a single material because both filament switches are connected to the same controller input.  We generally use a ~100mm piece to load in the second sensor if running a single material print.

Wiring check

Ensure the sensors are connected to each other and also connected to the machine wiring harness correctly and that no plugs are loose or damaged.

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