Z-offset with BL Touch
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Hi all,
I've tried to find answers to this from other questions but am still unsure so thought I'd better ask..
I'm having trouble with my z offset (BL touch probe). I'm currently using manual bed levelling and no mesh calibration.
So I get my bed levelled manually by probing with G30, then sending G1Z0 at the corners and centre of the bed (glass) and using thumbscrews to adjust the bed height. I then repeat this process a couple of times to ensure all locations are as close to 0.1mm from the bed as possible.
Then I start printing and instantly the nozzle crashes into the bed and I have to raised the bed using the baby height adjustments to around 0.8mm. I don't understand what is causing this problem. Hopefully the following system files and print g-code should help identify the issue?
config.g
; Configuration file for Duet WiFi (firmware version 1.20 or newer) ; executed by the firmware on start-up ; ; generated by RepRapFirmware Configuration Tool on Wed Mar 07 2018 10:07:16 GMT+0000 (GMT) ; General preferences G90 ; Send absolute coordinates... M83 ; ...but relative extruder moves M555 P1 ; Set firmware compatibility to look like RepRapFirmare ; Network M550 Pxxxxxxx ; Set machine name M551 Pxxxxxxx ; Set password M552 S1 ; Enable network M586 P0 S1 ; Enable HTTP M586 P1 S0 ; Disable FTP M586 P2 S0 ; Disable Telnet ; Drives M569 P0 S0 ; Drive 0 goes backwards 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 Z400 E199.99 ; Set steps per mm M566 X480 Y480 Z12 E120 ; Set maximum instantaneous speed changes (mm/min) M203 X9001 Y3000 Z600 E3000 ; Set maximum speeds (mm/min) M201 X800 Y800 Z100 E5000 ; Set accelerations (mm/s^2) M906 X760 Y900 Z760 E1500 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 X190 Y200 Z175 S0 ; Set axis maxima ; Endstops M574 X1 Y1 S0 ; Set active low endstops ; Z-Probe M307 H3 A-1 C-1 D-1 ; M558 P9 H5 F160 R0.250 T2000 A3 ; Set Z probe type to bl touch and the dive height + speeds G31 X41 Y-47 Z3.25 P25 ; Set Z probe trigger value, offset and trigger height M557 X18:182 Y18:182 S25 ; Define mesh grid ; 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 B3988 C0 R4700 ; Set thermistor + ADC parameters for heater 0 M143 H0 S120 ; Set temperature limit for heater 0 to 120C M305 P1 T100000 B4725 C0 R4700 ; Set thermistor + ADC parameters for heater 1 M143 H1 S280 ; Set temperature limit for heater 1 to 280C M307 H0 A90.0 C700.0 D10.0 S1.00 V0.0 B1 ; PID tuning - set automatically (M303) and moved from config-override.g M307 H1 A458.2 C201.5 D3.2 S1.00 V24.0 B0 ; PID tuning - set automatically (M303) and moved from config-override.g M307 H2 A340.0 C140.0 D5.5 S1.00 V0.0 B0 ; PID tuning - set automatically (M303) and moved from config-override.g M307 H4 A340.0 C140.0 D5.5 S1.00 V0.0 B0 ; PID tuning - set automatically (M303) and moved from config-override.g M307 H5 A340.0 C140.0 D5.5 S1.00 V0.0 B0 ; PID tuning - set automatically (M303) and moved from config-override.g M307 H6 A340.0 C140.0 D5.5 S1.00 V0.0 B0 ; PID tuning - set automatically (M303) and moved from config-override.g M307 H7 A340.0 C140.0 D5.5 S1.00 V0.0 B0 ; PID tuning - set automatically (M303) and moved from config-override.g ; 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 H T45 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on M106 P2 S1 I0 F500 H 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 saving after power loss is not enabled ; Custom settings are not configured M572 D0 S0 ; Disable Pressure Advance ; Miscellaneous T0 ; Select first toolhomeall.g
; homeall.g ; called to home all axes ; ; generated by RepRapFirmware Configuration Tool on Wed Mar 07 2018 10:07:16 GMT+0000 (GMT) M280 P3 S160 I1 ; Z probe alarm release ; M280 P3 S10 I1 ; deploy Z probe G91 ; relative positioning G1 S2 Z5 F6000 ; lift Z relative to current position G1 S1 X-205 Y-205 F6000 ; move quickly to X and Y axis endstops and stop there (first pass) G1 X5 Y5 F6000 ; go back a few mm G1 S1 X-205 Y-205 F600 ; move slowly to X and Y axis endstops once more (second pass) G90 ; absolute positioning G1 X59 Y147 F6000 ; go to probe point - centre of bed G30 ; home Z by probing the bed G1 Z5 F100. ; uncomment this line to lift the nozzle after hominghomez.g
; homez.g ; called to home the Z axis ; ; generated by RepRapFirmware Configuration Tool on Wed Mar 07 2018 10:07:16 GMT+0000 (GMT) M280 P3 S160 I1 ; Z probe alarm release ; M280 P3 S10 I1 ; deploy Z probe G91 ; relative positioning G1 S2 Z5 F6000 ; lift Z relative to current position G90 ; absolute positioning G1 X59 Y147 F6000 ; go to probe point - centre of bed G30 ; home Z by probing the bed G1 Z5 F6000 ; lift Z after homingprint_file.gcode
; G-Code generated by Simplify3D(R) Version 4.0.0 ; Jun 2, 2018 at 3:33:59 PM ; Settings Summary ; .... abbreviated for brevity G90 M83 M106 S0 M140 S55 M190 S55 M104 S215 T0 M109 S215 T0 G28 ; Home all M561 ; Clear any bed transform that might be in place ;G29 S1 ; Load bed mesh analysis G1 Z5 F6000 ; Move Z to 5 G1 X5 Y5 ; Move Head to front left G92 E0 ; Zero Extruder G1 F200 E4 ; Prime the extruder G92 E0 ; Zero Extruder G1 E-2.0000 F3000 G1 Z0.180 F1002 ; process Process1-1-5 ; layer 1, Z = 0.180 T0 ; tool H0.200 W0.528 ; skirt G1 X84.105 Y87.840 F9000 G1 E1.8000 F900 G1 X105.895 Y87.840 E0.9566 F720 G1 X107.160 Y89.105 E0.0786 G1 X107.160 Y110.895 E0.9566 G1 X105.895 Y112.160 E0.0786 .... -
Check that the trigger height of the bltouch remains constant when you probe the bed multiple times in the same spot using G30 S-1. If it doesn't, then you may need to reduce the probing speed (F parameter in the M558 command).
