I just did it! Printed something with carbon filament, which really likes to clogg if not enough throughput is on the nozzle. So I canceled the print, took my digital calliper and measured the printed height was 12,8mm.
To continue printing at this height you have to lower the model 12,8mm below the printing surface. The printed part will be skipped automatically if it is below the build level.
Next thing is to modify the Starting script g-code in the "Scripts" tab. This script basically does the adjustment routine before the printing starts. Last thing it does is extruding some filament on the most outer side of the build platform and then printing starts. You have to make sure to move the build plate out of the way before the extruders go into the wait position for heating up.
I ADVICE YOU TO DO THIS ONLY WITH PRECAUTION. KEEP A FINGER ON THE OFF SWITCH OF YOUR PRINTER. IF YOU DO SOMETHING WRONG, THE EXTRUDERS WILL RUN INTO THE PREVIOUSLY PRINTED OBJECT!!!
Basically I added G-Code to move the platform downwards to the last printed layer before the extruders are moved into the waiting position. It started printing exactly 12,8mm where the last build failed.
Here is the G-Code:
Code: Select all
; **** Replicator 1 dual start.gcode ****
M73 P0 ; Enable build progress
G162 X Y F3000 ; Home XY maximum
G161 Z F1200 ; Home Z minimum
G92 Z-5 ; Set Z to -5
G1 Z0 ; Move Z to 0
G161 Z F100 ; Home Z slowly
G1 Z7.44 ; Move Z to 7.44 to restart printing at this position
M132 X Y Z A B ; Recall home offsets
M135 T0 ; Load right extruder offsets
G1 X-120 Y-70 F9000 ; Move to wait position off table
G130 X20 Y20 Z20 A20 B20 ; Lower stepper Vrefs while heating
M126 S[fan_speed_pwm] ; Set fan speed
M140 S[bed0_temperature] T0 ; Heat buildplate
M134 T0 ; Stabilize bed temperature
M104 S[extruder0_temperature] T0 ; Heat right extruder
M133 T0 ; Stabilize right extruder temperature
G130 X127 Y127 Z40 A127 B127 ; Default stepper Vrefs
G92 A0 B0 ; Zero extruders
G1 X100 Y-73 F9000 ; Move to front right corner of bed
G1 X-90 Y-73 E24 F2000 ; Extrude a line of filament across the front edge of the bed
G1 X-100 Y-73 F180 ; Wait for ooze
G1 X-110 Y-73 F5000 ; Fast wipe
M73 P1 ;@body (notify GPX body has started)
; **** end of start.gcode ****
Add Line 8: "G1 Z7.44 ; Move Z to 7.44 to restart printing at this position"
G-Code to level build plate to the last layer after failing. Note that I had to subtract 5mm due to the adjustment in Line 5, where the Z-Axis gets set by -5mm. Better to keep this since things can get weird if the axis are not zeroed as expected by the printer.
Modify Line 11: "G1 X-120 Y-70 F9000 ; Move to wait position off table"
Removed instruction to move the build plate (Z-axis) because we adjusted it in line 8 to make sure extruders won't move into the already build object.
Remove the following two lines at around line 20 and 24 so the build plate stays on the last printed layer:
"G1 Z0.3 F6000 ; Move down to purge"
"G1 Z0.5 F100 ; Lift"
At the beginning try to remove any oozed out filament by hand before the printing continues.
As I mentioned before: This procedure is risky! You might damage your printer if you are not very carefull or even hurt yourself while fiddling around. Try this only if you know what you are doing. I am not responsible for any damage caused to you or your printer.
Hope this helps out.