MINTEMP ERR: nozzle temperature too low

[Apie56]

Good day.

Please find attached my configuration files. I continue to get a MINTEMP error on my Ender 3 v2.

Sometimes, when I turn off the printer and turn it on again, I no longer get the error, but also sometimes, when I use the reboot function on the screen, I no longer get the error. However, most of the time, the printer continues to give me the error. The strange thing is, that the PID works perfectly fine. I have run multiple cycles from 195 degrees C up to 275 degrees C, fan on and off, bed heated and not, with no issues.

As soon as I start heating the hotend; manually, through a preset, or print start; I get the MINTEMP error.

The thermistor is working, and I have tried with a new thermistor and still get the same resulting error. You will note that I have enabled high thermistor support in the attached configuration_adv.h file to try and counteract this, but it does not make a difference.

I have also tried this solution, I've tried flashing firmware and compared my configurations to precompiled configs, with no success. The firmware I have flashed is from the September release.

Additional:
Board: creality v4.2.2 RE
Hotend: creality sprite
Thermistor: 100k ntc
Heater: 50W
Silicone sock: yes
Enclosure: yes

Thanks in advance.
Configuration.zip

[tokolist]

It seems to be Marlin temperature reading instability issue. On 20230803 (and earlier) I was facing it once per a couple of month. On 20230925 I was getting it constantly until I set below value in Configuration_adv.h and it got fixed for me. I also added it to my _printers configuration to make it permanent solution. You might want to test lower values if you care about safety more than me :)

#define MAX_CONSECUTIVE_LOW_TEMPERATURE_ERROR_ALLOWED 10

  {
    "op": "CustomVal",
    "searchfor": "MAX_CONSECUTIVE_LOW_TEMPERATURE_ERROR_ALLOWED",
    "value": "10",
    "comment": "Fixes MINTEMP issue caused by unstable temperature readings"
  }

[mistergates]

Hi, I am facing exactly the same issue with my Ender 3 V2 I've replaced the thermistors, but unable to resolve this. The temperature keeps fluctuating and drops at random instances. I am not well versed to coding or editing G-codes. Can you please help me resolve this. Thanks.

Also having the same issue on my Ender 3 v2. Temperatures are stable until the print starts, then it rapidly drops and reports nozzle temp too low error.

[Apie56]

Reverting to a previous release fixed my issue. Not the best fix, but it works. What firmware/build do you have? Do you have a heat sock? have you checked your thermistor wiring?

[mistergates]

@Apie56 which release did you revert to? I was on the July 2024 release, precompiled release build Ender_422_BLT-ProUI-EX-07-26.bin. Heat sock is on and thermal wiring is good, I have no issues with creality or jyers firmware.

[Apie56]

I reverted to December 2023. I recommend running pid tuning, and if that doesn't work, roll back to 2023. Another thing you can try is increasing the high-temperature support time in configuration_adv.h. It isn't recommended to do so, but could you try to see if it fixes your issue? The following lines are applicable:

• The solution: Once the temperature reaches the target, start observing.

• If the temperature stays too far below the target (hysteresis) for too

• long (period), the firmware will halt the machine as a safety precaution.

• If you get false positives for "Thermal Runaway", increase

• THERMAL_PROTECTION_HYSTERESIS and/or THERMAL_PROTECTION_PERIOD
  */
  #if ENABLED(THERMAL_PROTECTION_HOTENDS)
  #define THERMAL_PROTECTION_PERIOD 40 // (seconds)
  #define THERMAL_PROTECTION_HYSTERESIS 4 // (°C)

• If you get false positives for "Heating failed", increase WATCH_TEMP_PERIOD

• and/or decrease WATCH_TEMP_INCREASE. WATCH_TEMP_INCREASE should not be set

• below 2.
  */
  #define WATCH_TEMP_PERIOD 40 // (seconds) // Ender Configs
  #define WATCH_TEMP_INCREASE 2 // (°C)

// The number of consecutive low temperature errors that can occur
// before a MINTEMP error is triggered. (Shouldn't be more than 10.)
//#define MAX_CONSECUTIVE_LOW_TEMPERATURE_ERROR_ALLOWED 0

[Apie56]

See also the following:
(https://github.com/mriscoc/Ender3V2S1/discussions/1092#discussioncomment-7110384)
(https://github.com/mriscoc/Ender3V2S1/discussions/1092#discussioncomment-7104127)

[mriscoc]

ALM (https://github.com/mriscoc/Ender3V2S1/wiki/Adaptive-Mesh-Leveling-(AML)) could give you better results

[tokolist]

purchased pack, will be testing it

[tokolist]

@mriscoc I have adapted post processing script to PrusaSlicer startup gcode macro, so one doesn't have to install python, libs and configure it. Since it works natively, it also visualizes purge line and it's easy to update right in PrusaSlicer. I think I need your permission to share it publicaly or let me know if I can share it with you privately. You might consider adding it to pack.

Overall I'm happy with results, but I'm still testing it and can see some potential improvements. For instance, purge line for big model is going to be huge and it should be limited by some value.

[mriscoc]

Hi, thanks, I the use a script for easy maintain and for keep the start script clean. Python and the libraries are also required for the thumbnail preview. You can share your start script but not here or in ProF social media to avoid confusions.

[tokolist]

thanks, I will share it as a secret gist and mention that it's unsupported by Professional Firmware author in case somebody wants to use it

[tokolist]

and I will push to purchase AML pack first :)

[mistergates]

Thanks for the info! I actually went to the latest release, UBL pre-compiled version and I'm no longer seeing the issue.

…

On Mon, Aug 19, 2024, 4:19 PM Anton Sithole ***@***.***> wrote: I reverted to December 2023. I recommend running pid tuning, and if that doesn't work, roll back to 2023. Another thing you can try is increasing the high-temperature support time in configuration_adv.h. It isn't recommended to do so, but could you try to see if it fixes your issue? The following lines are applicable: - The solution: Once the temperature reaches the target, start observing. - If the temperature stays too far below the target (hysteresis) for too - long (period), the firmware will halt the machine as a safety precaution. - - If you get false positives for "Thermal Runaway", increase - THERMAL_PROTECTION_HYSTERESIS and/or THERMAL_PROTECTION_PERIOD */ #if ENABLED(THERMAL_PROTECTION_HOTENDS) #define THERMAL_PROTECTION_PERIOD 40 // (seconds) #define THERMAL_PROTECTION_HYSTERESIS 4 // (°C) - If you get false positives for "Heating failed", increase WATCH_TEMP_PERIOD - and/or decrease WATCH_TEMP_INCREASE. WATCH_TEMP_INCREASE should not be set - below 2. */ #define WATCH_TEMP_PERIOD 40 // (seconds) // Ender Configs #define WATCH_TEMP_INCREASE 2 // (°C) // The number of consecutive low temperature errors that can occur // before a MINTEMP error is triggered. (Shouldn't be more than 10.) //#define MAX_CONSECUTIVE_LOW_TEMPERATURE_ERROR_ALLOWED 0 — Reply to this email directly, view it on GitHub <#1092 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AC2SRIKESGTF5WSOQEP7QETZSJONJAVCNFSM6AAAAABLK2RLKOVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTAMZYHA3TGNA> . You are receiving this because you commented.Message ID: ***@***.***>