Confused on IR sensor MK3 to MK3S  

Active Member


A few months ago I upgraded my MK3 to an MK3S with MMU2S, following the guide. In this guide, and the kit I received, the filament sensor has a chimney and works like s sort of see-saw. This system does not work well. I have problems getting the sensor calibrated.

To my surprise, when I read the manual for upgrading just the MK3 to the MK3S, the sensor is completely different! It uses a ball. That's more like it. Did I miss something. What is the correct and best manual? I am confused.


Posted : 07/10/2019 8:47 pm

Hi Frank, 

The tower sensor is the correct one for MMU2S/Mk3S

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 07/10/2019 9:49 pm
Dave Avery
Honorable Member

mk3 to mk3s switches sensor from laser motion detection to IR+ ball

mk3 or mk3s mod to MMU2 switches to chimney and long arm tension door and moves the mk3s sensor to the chimney and removes the ball

the non-MMU setups use the sensor to enable autoload

the MMU setup uses the sensor to to tell the MMU the filament has engaged the extruder bondtech gears

This post was modified 2 years ago by Dave Avery
Posted : 08/10/2019 3:00 pm
Active Member


That makes sense, thanks.

Posted : 08/10/2019 9:01 pm

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