Temperature reading (sometimes) unstable



  • Hi, I searched for someone with the same problem, but couldn't find something that describes my situation.

    I am running a Tevo little monster with a (genuine) E3D volcano and a brand new duet 2 wifi. In order to switch out the chinese knock of parts, I had to recrimp all the connectors for the thermistor, so I am very confident that the wiring is fine. Also, I double checked it.
    Now, sometimes during printing, the temperature reading from the heater becomes unstable. This only occurs when the effector is actually moving, never when it stands still. However, it is not always present and also somehow likely to even disappear completely after a while during the same print (see attached screenshot).
    0_1541874112006_96201976-71d3-489a-a9aa-d4e1bc3b42d6-image.png
    My setup for the thermistor is: M305 P1 T100000 B4725 C7.060000e-8 R4700
    The input voltage seems to be stable at all times.

    Any ideas what could possibly cause this issue?

    Thanks very much in advance for any help.

    jm


  • administrators

    @jm-kiefer the most likely causes are:

    • A loose connection (I know you have checked them).
    • Deteriorating wires within the moving loom (i.e the individuals cores of the wires breaking making the connection change in resistance as it moves to certain points)
    • Electrical noise from some other part of the system.

    In order to diagnose further you need to try and recreate the issue in a repeatable way.



  • Hi T3P3Tony,

    thanks very much for the quick help. Finding a movement that makes the issue repeatable was the key here. Turns out, that the way my cables were tightened some positions of the effector caused a tension on the connector. I removed that tension by changing the routing of the wires and so far it looks like the problem's gone. I'm optimistic that this was the cause.
    Thanks again.

    jm


 

Looks like your connection to Duet3D was lost, please wait while we try to reconnect.