CORE XY 3D Printer - Add a Filament Detector

How to add a Filament Detector to your ReP_AL COREXY Printer


Mega annoying when you have a long print running and you come back to find out the filament ran out and the printer happily continued to print nothing for the next 10 hours......


That's why a cheap filament detector is worth the investment and super easy to install. The filament sensor I used is available here




Step 1: Print the Bracket

This is available on the GITHUB site.  Its just a simple bracket to clamp from the frame to the filament detector.  M3 bolts in the Filament detector. M4 in the frame with some locking T nuts.




Step 2: Connection to the TFT Control Board

The filament sensor is connected to the TFT Control Board and not to the MKS Board.  The TFT will then handle all the filament change procedure.


Connection is as follows:

Blue: Signal      /      Black: Negative -ve    /    Red: Positive   +ve



Ensure that the +ve -ve and signal wires are correctly connected.  Sometimes the red wire on the filament detector switch is actually the signal wire.

To allow the cables to pass through the 3D printed frame you will need to cut a small section out of the 3D printed TFT display frame for the filament detector cable connector head.


Step 3: Code Updates on the TFT Config File:

In the TFT Display config file (Not the micro SD of the MKS Board) make the following changes to the config code:


Code Before:

Change To:

The trigger_level gives the active high or low signal.  Change to 1 or 0 depending on how your filament switch is triggered.  (my detector needed a 1)



Pause Position:

The position where the printer will move to when the filament switch is triggered can be defined here:



Once the filament detector switch is activated the printer will move to the pause position and start beeping to inform you that the filament is empty.

Once the filament has been replaced the printer can be restarted and the print continues.