Nozzle tip is not at correct height before start of print
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Hi
I had posted previously about the fact that when I begin a print, I have some start g code that homes all axis, primes some filament and then begins to print. the problem is that when the print starts the nozzle is about 5mm above the heatbed, so I stop the job, reload the code file again, and start the print everything is fine and nozzle is at correct height. I have posted my config file and home z and home all files also. What is wrong ?; Configuration file for Duet WiFi (firmware version 2.03)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v2.1.3 on Wed Nov 27 2019 02:27:21 GMT-0500 (EST); General preferences
G90 ; send absolute coordinates...
M83 ; ...but relative extruder moves
M550 P"ALPHA 300" ; 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
M569 P1 S0 ; physical drive 1 goes backwards
M569 P2 S0 ; physical drive 2 goes backwards
M569 P3 S0 ; physical drive 3 goes backwards
M584 X0 Y1 Z2 E3 ; set drive mapping
M350 X16 Y16 Z16 E16 I1 ; configure microstepping with interpolation
M92 X80.00 Y80.00 Z1600.00 E311.00 ; set steps per mm
M566 X900.00 Y900.00 Z12.00 E120.00 ; set maximum instantaneous speed changes (mm/min)
M203 X6000.00 Y6000.00 Z300.00 E4200.00 ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z20.00 E250.00 ; set accelerations (mm/s^2)
M906 X1050 Y1050 Z1250 E1050 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 X300 Y300 Z190.19 S0 ; set axis maxima; Endstops
M574 X1 Y1 Z2 S0 ; set active low end endstops; Z-Probe
;M558 P0 H5 F120 T6000 ; disable Z probe but set dive height, probe speed and travel speed
;M557 X15:215 Y15:195 S20 ; define mesh grid; Heaters
M305 P0 T100000 B4138 R4700 ; set thermistor + ADC parameters for heater 0
M143 H0 S80 ; set temperature limit for heater 0 to 80C
M305 P1 T100000 B4138 R4700 ; set thermistor + ADC parameters for heater 1
M143 H1 S260 ; set temperature limit for heater 1 to 260C; Fans
M106 P0 S1 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 H-1 ; set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned OFF; Tools
M563 P0 S"NOZZLE " 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
; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool v2.1.3 on Wed Nov 27 2019 02:27:21 GMT-0500 (EST)
G91 ; relative positioning
G1 H2 Z5 F300 ; lift Z relative to current position
G1 H1 X-305 Y-305 F1800 ; move quickly to X and Y axis endstops and stop there (first pass)
G1 H2 X5 Y5 F6000 ; go back a few mm
G1 H1 X-305 Y-305 F360 ; move slowly to X and Y axis endstops once more (second pass)
G1 H1 Z195.19 F300 ; move Z up stopping at the endstop
G90 ; absolute positioning
G92 Z190.19 ; set Z to axis minimum (you may want to adjust this); Uncomment the following lines to lift Z after probing
;G91 ; relative positioning
;G1 S2 Z5 F100 ; lift Z relative to current position
;G90 ; absolute positioning; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool v2.1.3 on Wed Nov 27 2019 02:27:21 GMT-0500 (EST)
G91 ; relative positioning
G1 H2 Z5 F300 ; lift Z relative to current position
G1 H1 Z195.19 F300 ; move Z up until the endstop is triggered
G92 Z190.19 ; set Z position to axis minimum (you may want to adjust this); Uncomment the following lines to lift Z after probing
;G91 ; relative positioning
;G1 H2 Z5 F100 ; lift Z relative to current position
;G90 ; absolute positioning -
@ScaraMan said in Nozzle tip is not at correct height before start of print:
.............. I have some start g code that homes all axis, primes some filament and then begins to print. the problem is that when the print starts the nozzle is about 5mm above the heatbed, so I stop the job, reload the code file again, and start the print everything is fine and nozzle is at correct height.
From that, I'd say that the source of the problem lies within that start.g code. Can you post that too.
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;FLAVOR:RepRap
;TIME:32505
;Filament used: 11.5317m
;Layer height: 0.25
;Generated with Cura_SteamEngine 3.6.0
T0
M190 S60
M104 S210
M109 S210
M82 ;absolute extrusion mode
G1 X30 Y30 Z170
G92 E0 ; Reset extruder
G1 X30 Y30 F4000 ;move X/Y to front of printer
G1 Z15.0 F9000 ;move the platform to 15mm
G4 5000
G92 E0 ;zero the extruded length
G1 F200 E50 ;extrude 10 mm of feed stock
64 10000
G92 E0 ;zero the extruded length again
G4 1000
M83 ;relative extrusion mode
G1 F1500 E-6.5
;LAYER_COUNT:181
;LAYER:0
M107
G0 F7500 X173.774 Y25.353 Z0.15
;TYPE:SKIRT
G1 F1500 E6.5
G1 F1050 X173.893 Y24.815 E0.00518
G1 X174.089 Y24.3 E0.00518
G1 X174.357 Y23.819 E0.00518
continued -
@ScaraMan I don't see anything amiss with that but at the same time, I don't see anything that calls the homing macros which you referred to when you said "I have some start g code that homes all axis......."
I did notice that your home Z has a G91 to set the positioning to relative but no G90 to put it back to absolute and there is no G90 in your start gcode that I can see. So if you ran home Z then that start code, the G1 Z15 would move the head by 15mm from it's current position, rather than to 15mm from the bed. That might explain the 5mm difference. If so putting G90 in your start code might fix it, but I don't think I have the full picture of exactly what commands you are sending.
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@ScaraMan said in Nozzle tip is not at correct height before start of print:
What exactly are you doing when you start a print? Running homeall.g, then running print gcode, cancelling, running homez.g, then running the print gcode again?
Your homez.g does not return to absolute positioning. It should be:
; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool v2.1.3 on Wed Nov 27 2019 02:27:21 GMT-0500 (EST)
G91 ; relative positioning
G1 H2 Z5 F300 ; lift Z relative to current position
G1 H1 Z195.19 F300 ; move Z up until the endstop is triggered
G90 ; absolute positioning
G92 Z190.19 ; set Z position to axis minimum (you may want to adjust this)Without this, any move in the gcode after this would move in relative mode, until it was turned back to absolute mode.
I don't think you need the
G92 Z190.19at the end of homeall.g and homez.g, as the preceding move is an H1 move, which sets the axis position defined by M208 in config.g (M208 X300 Y300 Z190.19 S0 ; set axis maxima) when it hits the endstop. But not sure why this would effect the first run of the homeall.gAlso, in the start of your gcode print file:
...
G1 F200 E50 ;extrude 10 mm of feed stock
64 10000
G92 E0 ;zero the extruded length again
...I think that should be
G4 10000. Not sure of the effect of this.Ian
Edit: @deckingman spotted the same thing!
