The Heater Fault that gave me a heart attack



  • Today I got some heater faults on my hotend. Out of some reason the heater first was unable to maintain or reach temperature and then it somehow did but was largely swinging around the target temperature of +-10°C. I never had that before and as I cleared the heater fault already once before I let it at that until I could have a more detailed look.

    When I looked at my Duet tonight there was nothing obviously wrong. Nothing seemed to be changed or damaged, all wires were tight at both ends, the hotend and the Duet.

    So I started to unscrew the wires in the heater terminals on the Duet and suddenly the terminal block started to wiggle around. I was like "oh no! My Duet is broken...". I removed all wires and plugs, unscrewed the Duet from its case and yes, the terminal could be swung back and forth just about a millimeter with very gentle taps.
    normal
    swung back

    And then I found that the same but less movement could be done on the main VIN/GND terminal. Again another panic attack. Will this be under warranty? I have to write a mail to @T3P3Tony and also mention the minor soldering issues I had found on the board already a while ago and posted in a thread somewhere here... this surely has to be under warranty... panic!

    The other hotend terminal was rock solid.

    OK but I need to check first if I can (not) reproduce the heater fault with the second heater terminal, so I loosened its screws and... tada, it can swing back and forth. 🤦 After tightening the screws again it was rock solid. In fact all of them were. Nearly died because of "designed like this". 😂

    In the end I reassembled everything (in steps) and the heater fault is gone. No clue what it was. But I could use the incident to finally compare my hotend thermistor against my BBQ thermometer which I guess is thoroughly calibrated (it has to be with this price tag 😄 ) and surprisingly they show quite the same temp. I did not expect that.



  • Hey,

    observed the same. Used Hot Glue to fix it. Rock solid now.. tbc



  • @crynool Actually it is totally solid as soon as the screws are tightened so I assume it is just built like this.

    @T3P3Tony and @dc42 Is it actually intended to be like that?


  • administrators

    Yes this is typical of rising-clamp terminal blocks. The heater terminal blocks on the Smart Effector behave like this too.



  • @dc42 Thanks for confirming.

    P.S.: Also no more heater fault at today's print.


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