Thermister stated temp higher than actual



  • Hi Guys,

    I've run autotuning for the E3D Volcano that I've recently installed with a Duet2 Wifi board and a Smart Effector.
    However, after heating up the thermister is reading 235C, but I'm not able to extrude any PLA. I checked the actual temp of the hot-end nozzle, and it's only at 215F, while the thermister is reading 235C. Oddly the temperature does appear to be accurate at room temperature. My config.g and override are below. Please help!

    ; Configuration file for Duet WiFi (firmware version 1.20 or newer)
    ; executed by the firmware on start-up
    ;
    ; generated by RepRapFirmware Configuration Tool on Thu Jul 12 2018 20:54:00 GMT-0500 (Central Daylight Time)

    ; General preferences
    G90 ; Send absolute coordinates...
    M83 ; ...but relative extruder moves

    ;*** The homed height is deliberately set too high in the following - you will adjust it during calibration.

    ; After G32 auto-calibrate, copied from config-override.g
    ; Note: G31 Z (below) affects M665 H, and this is NOT yet calibrated.
    M665 L288.180 R134.638 H217.025 B105.0 X-0.477 Y-0.304 Z0.000
    M666 X-0.910 Y0.111 Z0.799 A0.00 B0.00

    ;Manually copied from Marlin config.h in Anycubic's github repository
    ;M665 R135.4 L271.5 B105 H300 ; Set delta radius, diagonal rod length, printable radius and homed height
    ;M666 X0 Y0 Z0 ; Put your endstop adjustments here, or let auto calibration find them

    ; Network
    M550 PAKL Plus ; Set machine name
    M552 S1 ; Enable network
    ;*** Access point is configured manually via M587
    M552 P192.168.0.10 ;trying to create a static IP address
    ;M554 P68.5.168.1 ;gateway
    ;M553 P255.255.252.0 ;netmask

    ; Drives
    M569 P0 S1 ; Drive 0 goes forwards
    M569 P1 S1 ; Drive 1 goes forwards
    M569 P2 S1 ; Drive 2 goes forwards
    M569 P3 S1 ; Drive 3 goes forwards
    M350 X16 Y16 Z16 E16 I1 ; Configure microstepping with interpolation
    M92 X80 Y80 Z80 E96.299 ; Set steps per mm. E=extruder
    M566 X300 Y300 Z300 E300 ; Set maximum instantaneous speed changes (mm/min)
    M203 X12000 Y12000 Z12000 E12000 ; Set maximum speeds (mm/min)
    M201 X3000 Y3000 Z3000 E3000 ; Set accelerations (mm/s^2)
    M906 X1000 Y1000 Z1000 E1000 I30 ; Set motor currents (mA) and motor idle factor in per cent
    M84 S30 ; Set idle timeout

    ; Axis Limits
    M208 Z0 S1 ; Set minimum Z

    ; Endstops
    M574 X2 Y2 Z2 S1 ; Set active high endstops

    ; Z-Probe
    M558 P8 R0.4 H3 F1200 T6000 ; Set Z probe type to switch and the dive height + speeds. A G31 command to set Z probe parameters must come after the M558 command that defines the Z probe.
    G31 P50 X0 Y0 Z-0.1 ; Set Z probe trigger value, offset and trigger height. G31 Pnnn (Trigger value) Xnnn(Probe X offset) Ynnn(Probe Y offset) Z(Trigger Z height) Cnnn(Temperature coefficient) Snnn (Calibration temperature)
    M557 R105 S20 ; Define mesh grid

    ; Heaters. Bed=H0, Extruders=H1, H2, H3 etc. T=resistence in ohms, P=channel, R=resistor on the board (4700 on Duet 2 Wifi)
    M305 P0 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 0
    M143 H0 S120 ; Set temperature limit for heater 0 to 120C
    M305 P1 T100000 B4138 C3.606903e-7 R4700 ; Set thermistor + ADC parameters for heater 1
    M143 H1 S280 ; Set temperature limit for heater 1 to 280C
    M307 H1 A341.3 C265.8 D4.7 V12.8 B0

    ; Fans
    M106 P0 S0.3 I0 F500 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
    M106 P1 S1 I0 F500 H1 T45 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on
    M106 P2 S1 I0 F500 H1 T45 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on

    ; Tools
    M563 P0 D0 H1 ; Define tool 0
    G10 P0 X0 Y0 Z0 ; Set tool 0 axis offsets
    G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C

    ; Automatic power saving
    M911 S10 R11 P"M913 X0 Y0 G91 M83 G1 Z3 E-5 F1000" ; Set voltage thresholds and actions to run on power loss

    ; Custom settings are not configured

    ; Miscellaneous
    M501 ; Load saved parameters from non-volatile memory
    T0 ; Select first tool


    ; config-override.g file generated in response to M500 at 2020-05-04 16:22
    ; This is a system-generated file - do not edit
    ; Delta parameters
    M665 L288.180:288.180:288.180 R140.104 H221.975 B105.0 X0.387 Y0.297 Z0.000
    M666 X3.462 Y-0.038 Z-3.424 A0.00 B0.00
    ; Heater model parameters
    M307 H0 A156.2 C394.6 D1.2 S1.00 V12.7 B0
    M307 H1 A469.3 C286.8 D5.1 S0.50 V12.8 B0
    M307 H2 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    M307 H3 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    M307 H4 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    M307 H5 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    M307 H6 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    M307 H7 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    G10 L2 P1 X0.00 Y0.00 Z0.00
    G10 L2 P2 X0.00 Y0.00 Z0.00
    G10 L2 P3 X0.00 Y0.00 Z0.00
    G10 L2 P4 X0.00 Y0.00 Z0.00
    G10 L2 P5 X0.00 Y0.00 Z0.00
    G10 L2 P6 X0.00 Y0.00 Z0.00
    G10 L2 P7 X0.00 Y0.00 Z0.00
    G10 L2 P8 X0.00 Y0.00 Z0.00
    G10 L2 P9 X0.00 Y0.00 Z0.00


  • administrators

    Your M305 P1 settings are not the recommended ones for E3D thermistors.




  • administrators

    The correct values (the same ones as in that post) are also on the E3D documentation site.


Log in to reply