BLTouch bed leveling is always off

re_tour

Hey guys, I've been having a bit of trouble with my ender 3, namely that today I swapped the printing surface to a fresh one because the previous one was a bit worn out. Since then evergy G29 mesh calibration results in a similar way:
e7458c7d-982d-4361-af5d-c14a5a97ae2b-kép.png

I've been trying adjusting for over an hour now but every run returns a similar result to this: all corners are lower than the centre. What could be causing this? I tried setting the bed and bending the plate a little in case it got bent in such a parabolic shape.

Phaedrux

It's not so much important what the mesh looks like, it only matters if it produces a good first layer. If you print a first layer test does it work well?

re_tour

@phaedrux Unfortunately no. I set my new offset using the paper method, then started the print. The nozzle started digging into the bed instantly, so I set my Z offset 0.1 higher and tried again, but got the same result. I'm gonna leave this for tomorrow because I lost my patience with it for today.

I just don't get it, it worked beautifully until I changed the cover for the bed.

fcwilt

@re_tour

Are you setting the Z=0 Datum at bed center using a single G30 before creating/loading the height map?

Frederick

re_tour

@fcwilt At the moment my mesh.g looks like this:

if !move.axes[0].homed || !move.axes[1].homed || !move.axes[2].homed
 G28
M290 R0 S0    ;  clear baby stepping

G29 S2
 
; move to the center of the mesh with the PROBE (mind affset in Y is 25 above noozle)
G90
var xoffset = -45
var yoffset = -7
var xpos = {117.5 - var.xoffset}
var ypos = {117.5 - var.yoffset}
 
G1 X{var.xpos} Y{var.ypos} Z15 F6000
 
echo "Setting Probe Offset now"
G30 K0
G1 Z15 F3000
G29 S0

And my z-probe setting in config.g looks like this:

; Z-Probe
M950 S0 C"servo0"                              ; create servo pin 0 for BLTouch
M558 P9 C"^probe" H5 F300:120 A3 T6000         ; set Z probe type to bltouch and the dive height + speeds,the F300:120 first speed 300 second 120
G31 P500 X-45 Y-7 Z4.3                           ; set Z probe trigger value, offset and trigger height
M557 X30:190 Y30:190 P5                       ; define mesh grid

fcwilt

@re_tour

Just FYI here are two commands using the contents of the Object Model to position the probe at the center of the bed:

No variables required and any changes to the axes limits or probe offsets are taken into account each time the command is executed.

; move probe to center of bed (short form when center of bed is X=0 Y=0)

G1 X{-sensors.probes[0].offsets[0]}, Y{-sensors.probes[0].offsets[1]}, F12000

; move probe to center of bed (long form when center of bed is NOT X=0 Y=0)

G1 X{((move.axis[0].max + move.axis[0].min) / 2) - sensors.probes[0].offsets[0]}, Y{((move.axis[1].max + move.axis[1].min) / 2) - sensors.probes[0].offsets[1]}, F1800

mikeabuilder

If your new printing surface is a thin sheet with magnetic attach, maybe there is a bit of something under it in the center. Or if you replaced the PEI sheet on an existing stainless sheet, maybe you have a bubble. But I'm guessing a piece of gunk.

Phaedrux

@re_tour said in BLTouch bed leveling is always off:

M950 S0 C"servo0" ; create servo pin 0 for BLTouch
M558 P9 C"^probe"

Can you post your full config.g? Are those variables or something because they don't match any valid pin names.

re_tour

@mikeabuilder I ordered a magnetic one too, but I don't know, it seems way smaller than my original surface, is it supposed to be like that?!

re_tour

@phaedrux Sure thing, here it is:

; Configuration file for SKR-RFF-E3-v1.1 (firmware version 3)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v3.3.1-LPC-STM32+2 on Tue Dec 28 2021 01:07:55 GMT+0100

; General preferences
G90                                            ; send absolute coordinates...
M83                                            ; ...but relative extruder moves
M550 P"Ender3"                                 ; set printer name

; Network
M552 S1                                        ; enable network
M586 P0 S1                                     ; enable HTTP
M586 P1 S0                                     ; disable FTP
M586 P2 S0                                     ; disable Telnet

; Drives
M569 P0 S0                                     ; physical drive 0 goes backwards using TMC2209 driver timings
M569 P1 S0                                     ; physical drive 1 goes backwards using TMC2209 driver timings
M569 P2 S1                                     ; physical drive 2 goes forwards using TMC2209 driver timings
M569 P3 S0                                     ; physical drive 3 goes forwards using TMC2209 driver timings
M584 X0 Y1 Z2 E3                               ; set drive mapping
M350 X16 Y16 Z16 E16 I1                        ; configure microstepping with interpolation
M92 X80.00 Y80.00 Z400.00 E93.00               ; set steps per mm
M566 X1200.00 Y1200.00 Z60.00 E360.00          ; set maximum instantaneous speed changes (mm/min)
M203 X9000.00 Y9000.00 Z1800.00 E6000.00       ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z100.00 E5000.00          ; 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 X0 Y0 Z0 S1                               ; set axis minima
M208 X235 Y235 Z260 S0                         ; set axis maxima

; Endstops
M574 X1 S1 P"xstop"                            ; configure switch-type (e.g. microswitch) endstop for low end on X via pin xstop
M574 Y1 S1 P"ystop"                            ; configure switch-type (e.g. microswitch) endstop for low end on Y via pin ystop

; Z-Probe
M950 S0 C"servo0"                              ; create servo pin 0 for BLTouch
M558 P9 C"^probe" H5 F300:120 A3 T6000         ; set Z probe type to bltouch and the dive height + speeds,the F300:120 first speed 300 second 120
G31 P500 X-45 Y-7 Z4.3                           ; set Z probe trigger value, offset and trigger height
M557 X30:190 Y30:190 P5                       ; define mesh grid

; Heaters
M308 S0 P"bedtemp" Y"thermistor" T100000 B4092 ; configure sensor 0 as thermistor on pin bedtemp
M950 H0 C"bed" T0                              ; create bed heater output on bed and map it to sensor 0
M307 H0 B0 R0.365 C296.6 D3.97 S1.00 V24.0                               ; disable bang-bang mode for the bed heater and set PWM limit
M140 H0                                        ; map heated bed to heater 0
M143 H0 S120                                   ; set temperature limit for heater 0 to 120C
M143 H0 S120                                   ; set temperature limit for heater 0 to 120C
M308 S1 P"e0temp" Y"thermistor" T100000 B4092  ; configure sensor 1 as thermistor on pin e0temp
M950 H1 C"e0heat" T1                           ; create nozzle heater output on e0heat and map it to sensor 1
M307 H1 B0 R2.845 C121.4:119.4 D5.71 S1.00 V24.0                               ; disable bang-bang mode for heater  and set PWM limit
M143 H1 S245                                   ; set temperature limit for heater 1 to 245C

; Fans
M950 F0 C"fan0" Q500                           ; create fan 0 on pin fan0 and set its frequency
M106 P0 C"Part Cooling Fan" S0 H-1             ; set fan 0 name and value. Thermostatic control is turned off
M950 F1 C"fan1" Q500                           ; create fan 1 on pin fan1 and set its frequency
M106 P1 C"Hotend Fan" S0.01 H1 T45             ; set fan 1 name and value. Thermostatic control is turned on

; Tools
M563 P0 D0 H1 F0                               ; 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

; Custom settings are not defined

M918 P1 E4 E1000000

As of now, this is what's loaded onto the sdcard, haven't modified anything since last night.

Phaedrux

I'm surprised the bltouch works at all.

Can you send M122 and M98 P"config.g" in the Gcode console in DWC and post the results?

re_tour

@phaedrux said in BLTouch bed leveling is always off:

M98 P"config.g"

m122
=== Diagnostics ===
RepRapFirmware for STM32F4 based Boards (biquskr_rrf_e3_1.1) version 3.3.0_11 (2021-11-04 23:04:15) running on STM32F4
Used output buffers: 3 of 40 (11 max)
=== RTOS ===
Static ram: 21352
Dynamic ram: 81072 of which 24 recycled
Never used RAM 27596, free system stack 169 words
Tasks: NETWORK(ready,9.8%,251) HEAT(delaying,0.0%,343) Move(notifyWait,0.0%,361) FSWRITE(notifyWait,0.0%,566) MAIN(running,88.9%,446) IDLE(ready,1.3%,29), total 100.0%
Owned mutexes: WiFi(NETWORK)
=== Platform ===
Last reset 00:01:16 ago, cause: [power on/off]
Last software reset at 2022-01-05 23:06, reason: StuckInSpinLoop, Display spinning, available RAM 26860, slot 2
Software reset code 0x088f HFSR 0x00000000 CFSR 0x00000000 ICSR 0x0040080f BFAR 0xe000ed38 SP 0x100025c4 Task MAIN Freestk 782 ok
Stack: 080740b9 08073b14 210f0000 3f000000 4048fe2b 369dc3a0 3edb8886 3331bb4c 40000000 b5dde10a 388ab355 bb360b61 3e2aaaab 3f800000 3b800000 4117fc40 42a00000 3f000000 3f000000 20000010 40012c00 40012c00 080740b9 bb360b61 00010000 0000000d 00000040
Error status: 0x00
Step timer max interval 0
MCU temperature: min 19.2, current 28.9, max 28.9
Supply voltage: min 24.0, current 24.0, max 24.0, under voltage events: 0, over voltage events: 0, power good: yes
Heap OK, handles allocated/used 0/0, heap memory allocated/used/recyclable 0/0/0, gc cycles 0
Driver 0: position 0, 2209 standstill, reads 6632, writes 11, SG min/max not available
Driver 1: position 0, 2209 standstill, reads 6632, writes 11, SG min/max not available
Driver 2: position 0, 2209 standstill, reads 6632, writes 11, SG min/max not available
Driver 3: position 0, 2209 standstill, reads 6630, writes 12, SG min/max not available
Driver 4: position 0
Driver 5: position 0
Driver 6: position 0
Driver 7: position 0
Driver 8: position 0
Driver 9: position 0
Driver 10: position 0
Date/time: 2022-01-06 20:23:18
Slowest loop: 7.15ms; fastest: 0.08ms
=== Storage ===
Free file entries: 10
SD card 0 detected
SD card longest read time 1.4ms, write time 0.0ms, max retries 0
=== Move ===
DMs created 83, maxWait 0ms, bed compensation in use: none, comp offset 0.000
=== DDARing ===
Scheduled moves 0, completed moves 0, hiccups 0, stepErrors 0, LaErrors 0, Underruns [0, 0, 0], CDDA state -1
=== Heat ===
Bed heaters = 0, chamberHeaters = -1
=== GCodes ===
Segments left: 0
Movement lock held by null
HTTP is idle in state(s) 0
File is idle in state(s) 0
USB is idle in state(s) 0
Aux is idle in state(s) 0
Trigger is idle in state(s) 0
Queue is idle in state(s) 0
LCD is idle in state(s) 0
Daemon is idle in state(s) 0
Autopause is idle in state(s) 0
Code queue is empty.
=== Network ===
Slowest loop: 8.78ms; fastest: 0.00ms
Responder states: HTTP(1) HTTP(2) HTTP(0) HTTP(0)
HTTP sessions: 1 of 8
Uploads/Errors: 0/0
- WiFi -
Network state is active
WiFi module is connected to access point 
Failed messages: pending 0, notready 0, noresp 0
Bad header: 0/0
WiFi firmware version 1.25B0-01S-D
WiFi MAC address d8:d7:75:4b:85:6c
WiFi Vcc 3.42, reset reason Turned on by main processor
WiFi flash size 4194304, free heap 31664
WiFi IP address 192.168.1.79
WiFi signal strength -81dBm, mode 802.11n, reconnections 0, sleep mode modem
Clock register 00004002
Socket states: 0 2 4 0 0 0 0 0

	M98 P"config.g"
HTTP is enabled on port 80
FTP is disabled
TELNET is disabled

Phaedrux

@re_tour said in BLTouch bed leveling is always off:

RepRapFirmware for STM32F4 based Boards (biquskr_rrf_e3_1.1) version 3.3.0_11 (2021-11-04 23:04:15) running on STM32F4

Ah, ok.