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Solved Thermal Runaway Hotend

Discussion in 'Troubleshooting' started by izumi5188, Jan 17, 2019.

  1. izumi5188

    izumi5188 Member

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    Well back to you fine wizards of the forum. Before I buy a new Thermistor I have a couple of questions.

    I just replaced this Thermistor in my E3D v6 not to long ago. Broke the previous on a failed print. I've run PID auto tune on it. Everything seems to function fine in the center of the bed, but when the X Axis gets to the far left it jumps around. Before I say it's a bad Thermistor is there something else I should be checking? Could being that far on the X-Axis be bending the connector that much to give a false reading? Something on my control board?

    Secondly, I have several Semitec Thermistors, any reason I can't use kapton tape to secure one to the side? Not sure what settings in Marlin I need to change compared the canister ones.

    Thanks in advance you wizard gods. Let me know where I should send the beer.
     
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Kapton tape is fine. Will not be a problem. It may take a little longer to stabilize at temperature, but it will work that way.

    I'd start by flexing the wires and connectors with the print head int he middle somewhere and see if you can get the temperature to jump around. Since it only happens with the head in a certain position it is more likely a connector that is loose and giving bad readings when the wires flex a certain way.
     
  3. izumi5188

    izumi5188 Member

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    Thanks Mark.
    I'll try to see if I can get it to jump in the middle of the bed.

    Would you know as well, If I ever use the semitic thermistors, do I need to change anything in Marlin other than running PID?
     
  4. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Yes, you need to change the thermistor type.

    type "1" is the stock one:
    probably type "5" for the Semitec

    //// Temperature sensor settings:
    // -2 is thermocouple with MAX6675 (only for sensor 0)
    // -1 is thermocouple with AD595
    // 0 is not used
    // 1 is 100k thermistor - best choice for EPCOS 100k (4.7k pullup)
    // 2 is 200k thermistor - ATC Semitec 204GT-2 (4.7k pullup)
    // 3 is Mendel-parts thermistor (4.7k pullup)
    // 4 is 10k thermistor !! do not use it for a hotend. It gives bad resolution at high temp. !!
    // 5 is 100K thermistor - ATC Semitec 104GT-2 (Used in ParCan & J-Head) (4.7k pullup)
    // 6 is 100k EPCOS - Not as accurate as table 1 (created using a fluke thermocouple) (4.7k pullup)
    // 7 is 100k Honeywell thermistor 135-104LAG-J01 (4.7k pullup)
    // 71 is 100k Honeywell thermistor 135-104LAF-J01 (4.7k pullup)
    // 8 is 100k 0603 SMD Vishay NTCS0603E3104FXT (4.7k pullup)
    // 9 is 100k GE Sensing AL03006-58.2K-97-G1 (4.7k pullup)
    // 10 is 100k RS thermistor 198-961 (4.7k pullup)
    // 20 is the PT100 circuit found in the Ultimainboard V2.x
    // 60 is 100k Maker's Tool Works Kapton Bed Thermistor
    //
    // 1k ohm pullup tables - This is not normal, you would have to have changed out your 4.7k for 1k
    // (but gives greater accuracy and more stable PID)
    // 51 is 100k thermistor - EPCOS (1k pullup)
    // 52 is 200k thermistor - ATC Semitec 204GT-2 (1k pullup)
    // 55 is 100k thermistor - ATC Semitec 104GT-2 (Used in ParCan & J-Head) (1k pullup)
    //
    // 1047 is Pt1000 with 4k7 pullup
    // 1010 is Pt1000 with 1k pullup (non standard)
    // 147 is Pt100 with 4k7 pullup
    // 110 is Pt100 with 1k pullup (non standard)



    IIRC E3D uses Semitec (and it is type 5)
     
  5. izumi5188

    izumi5188 Member

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    Okay Mark,
    I tried giggle it around in the center and in the corner of the printer area where I saw it jumping around before it crashed. I couldn't get it to jump. I even turned my fan up to 100%, while my prints tend to only be 25% to see if I could cause it to happen. Nothing I did seemed to trigger it.

    Could I be over heating on the board? My small cooling fan fell off several weeks go when I was moving my machine, but this issue is new this week.

    Thanks.
     
  6. izumi5188

    izumi5188 Member

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    Well woke up to it broken at the connector. I guess I'm ordering more and trying to get the semitec one hooked up as well.
     
  7. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    If you mean the small fan under the printer that blows on the RAMPS board -- yes. Do not run without that :)
    They added it specifically for that reason (the original beta did not have one)
     
  8. izumi5188

    izumi5188 Member

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    Sensor wire was ended up breaking. Ordered new one, replaced and made sure leads were good on the motherboard.
     
    mark tomlinson likes this.

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