Trying to set up an external fault temp sensor



  • From a different thread that looks very similar I need to use the M305 command and virtual heaters but I just couldnt understand the replies.
    Im in the middle if a massive upgrade to my printer and so far my design has lightened my moving parts by 50 percent AND added a second extruder! New extruders are watercooled and fans replaced by directed air nozzles connected to air pump.
    I built a waterblock cooler for my main extruder and need to shut down the heater using a thermistor if the waterblock (or water itself) rises above expected threshold (say 35 deg). I have a PT100 on the main extruder.
    How exactly do I set this up? My chamber is not heated but Id like to keep that option open for the future. The second extruder will also have a PT100. My bed is heated also.
    Another consideration: With a second extruder im just going to run the output of one waterjacket to the input of the second one so a fault would presumably shut down both heaters. (can't imagine it wouldnt but justing being safe)
    thanks


  • administrators

    Set up your extra thermistor as a virtual heater using M305, then use M143 to monitor it. See https://duet3d.dozuki.com/Wiki/Gcode?revisionid=HEAD#Section_M143_Maximum_heater_temperature.