Autocalibration - Heat map always below bed

totalitarian

Can anyone explain why my heatmap always shows below the bed?

I have a BLTouch that is used to set the Z height and mesh.

Here are my configs

config.g

; Configuration file for Duet WiFi (firmware version 1.17 to 1.19)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool on Sun Dec 10 2017 14:24:02 GMT+0000 (GMT Standard Time)

; General preferences
M111 S0 ; Debugging off
G21 ; Work in millimetres
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves
M555 P2 ; Set firmware compatibility to look like Marlin

M667 S1 ; Select CoreXY mode
M208 X0 Y0 Z0 S1 ; Set axis minima
M208 X300 Y275 Z300 S0 ; Set axis maxima

; Endstops
M574 X1 Y2 Z1 S0 ; Set active high endstops

; Drives
M569 P0 S1 ; Drive 0 goes forwards
M569 P1 S1 ; Drive 1 goes forwards
M569 P2 S0 ; Drive 2 goes forwards
M569 P3 S0 ; Drive 3 goes forwards

M92 X80 Y80 Z1120 E400 ; Set steps per mm
M350 X16 Y16 I0 ; Configure microstepping with interpolation
M350 Z16 E16 I0 ; Configure microstepping with interpolation
M566 X1000 Y1000 Z200 E400 ; Set maximum instantaneous speed changes (mm/min)
M203 X12000 Y12000 Z2400 E24000 ; Set maximum speeds (mm/min)
M201 X1000 Y1000 Z10 E400 ; Set max accelerations (mm/s^2)
M204 P1200.000 T1600.000 R800.000 ; more acceleration
M906 X1050 Y1050 Z1050 E840 I30 ; Set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout

; Heaters
M301 H0 S1.00 P10 I0.1 D200 T0.4 W180 B30 ; Use PID on bed heater (may require further tuning)
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 C0 R4700 ; Set thermistor + ADC parameters for heater 1
M143 H1 S280 ; Set temperature limit for heater 1 to 280C

; Tools
M563 P0 D0 H1 F2; 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

; Network
M550 PGecko ; Set machine name
M552 S1 ; Enable network
M587 S"f1xter-ext" P"v1deoworld" ; Configure access point. You can delete this line once connected
M586 P0 S1 ; Enable HTTP
M586 P1 S1 ; Enable FTP
M586 P2 S1 ; Enable Telnet

; Fans
M106 P0 S0 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 S0 I0 F500 H-1 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned off

; Custom settings are not configured

; Miscellaneous
T0 ; Select first tool

;BLTouch
M307 H3 A-1 C-1 D-1 ;
M558 P5 X0 Y0 Z1 H5 F320 T6000; F probe speed - T Travel speed
G31 X30 Y5 Z0.6 P25
;INCREASE VALUE WILL LOWER NOZZLE CLOSER TO THE BED, DECREASE THIS VALUE WILL RAISE THE NOZZLE FROM THE BED
M557 X40:260 Y40:260 S55   ; probe from X=20 to 280, Y=20 to 280mm with a mesh spacing of 65mm
M501

Home all.g

; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool on Sun Oct 29 2017 11:44:20 GMT-0700 (MST)
; Relative positioning
G91
; Lift Z
G1 Z5 F6000
; Course home X or Y
G1 X-305 Y305 F1800 S1
; Course home X
G1 X-305 S1
; Course home Y
G1 Y305 S1
; Move away from the endstops
G1 X5 Y-5 F6000
; Fine home X
G1 X-305 F360 S1
; Fine home Y
G1 Y305 S1
G91                ; relative mode
G1 Z5 F320         ; raise head 5mm to ensure it is above the Z probe trigger height
G90                ; back to absolute mode
G1 X150 Y150 F2000 ; put head over the centre of the bed, or wherever you want to probe
M401; deploy probe
G30                ; lower head, stop when probe triggered and set Z to trigger height
M402; retract probe
; Absolute positioning
G90
; Tell the firmware where we are
;G92 Z0
; Uncomment the following line to lift the nozzle after probing
G1 Z5 F320

Override

; This is a system-generated file - do not edit
; Heater model parameters
M307 H0 A15.6 C85.1 D5.7 S0.40 B0
M307 H1 A225.0 C98.5 D6.1 S0.80 B0
M307 H2 A340.0 C140.0 D5.5 S1.00 B0

dc42

It usually means that the Z=0 position that is set by Z homing isn't accurate. But you are homing with the bltouch too. Are you sure that you don't have another G31 command somewhere that is setting a different Z probe trigger height?

totalitarian

Should I be setting

[c]G92 Z0[/c]

in my home.g and homeall.g?

dc42

@totalitarian:

Should I be setting

[c]G92 Z0[/c]

in my home.g and homeall.g?

Only if you are homing Z using a Z min endstop switch that triggers at exactly Z=0.

After homing Z, if you command the head to Z=0, is the nozzle just touching the bed?

Are you sure that mesh probing is succeeding? If it is failing for any reason, DWC could be displaying an old height map file.