G-Code start problems (extrusion is starting too late) after slicing with CURA
Hi there,
I can see that the PRUSA slicer is ignoring CAD details when doing the slicing (i am busy with the R/C model wings and fuselage). At first I thought it is related to the infill settings, but by now I am convinced that the PRUSA slicer is just not working.
So, I have downloaded the CURA slicer and now I am trying to generate G-code for my MK2/S MMU. That seems to be working fine, but the start G-code is wrong. Instead of pushing the filament into the hotend, the generated G-code is morving it backwards, leaving the nozzle empty.
And then the printing starts. After 3 layers or so, the nozzle has finally been filled and the material is coming out - but that's too late of course.
Now I have manually started to copy the MMU starting G-code into the G-code that has been produced by PRUSA - but so far I have not yet managed to achieve the result.
The ooze procedure starts, the filament is moved into the hotend - and then, just when the hotend starts to move to the printing area, the gears are moved backwards and that takes out the filament and the printing starts with "hot air".
Is anybody capable of reading G-code and letting me know, where I can uncomment this unnecessary behaviour?
Below the opening G-code from CURA, expanded with the start code from PRUSA. I suppose that some of the relevant lines have not been commented out yet.
Maybe one of you could give me some guideline where to look? Thanks, a lot, Harald
;G-code from CURA
;FLAVOR:Marlin
;TIME:3090
;Filament used: 3.12638m
;Layer height: 0.25
;Generated with Cura_SteamEngine 3.2.0
;end of G-code from CURA
;Inserted G-Code from PRUSA Slic3R
M115 U3.1.0 ; tell printer latest fw version
; Start G-Code sequence START
T? ;"Not sure if this has to be commented out"
;M104 S[first_layer_temperature] "Already in CURA code"
;M140 S[first_layer_bed_temperature] "Already in CURA code"
;M109 S[first_layer_temperature] "Already in CURA code"
;M190 S[first_layer_bed_temperature] "Already in CURA code"
;G21 ; set units to millimeters "Already in CURA code"
;G90 ; use absolute coordinates "Already in CURA code"
;M83 ; use relative distances for extrusion - "Not sure if this has to be commented in? I could find M82 inside the CURA code and decided to comment it out for now
;G28 W "Already in CURA code"
;G80 "Already in CURA code"
;G92 E0.0 "Already in CURA code"
;M203 E100 - "Manually inserted into CURA code below"
;M92 E140 - "Manually inserted into CURA code below"
;G1 Z0.250 F7200.000 - "Manually inserted into CURA code below"
;G1 X50.0 E80.0 F1000.0 - "Manually inserted into CURA code below"
;G1 X160.0 E20.0 F1000.0 - "Manually inserted into CURA code below"
;G1 Z0.200 F7200.000 - "Manually inserted into CURA code below"
;G1 X220.0 E13 F1000.0 - "Manually inserted into CURA code below"
;G1 X240.0 E0 F1000.0 - "Manually inserted into CURA code below"
;G1 E-4 F1000.0 - "Manually inserted into CURA code below"
;G92 E0.0 - "Manually inserted into CURA code below"
;End of inserted G-Code from PRUSA Slic3R
; Continuation of existing G-code from CURA
M82 ;absolute extrusion mode
G21 ; set units to millimeters
G90 ; use absolute positioning
M82 ; absolute extrusion mode
M104 S200 ; set extruder temp
M140 S60 ; set bed temp
M190 S60 ; wait for bed temp
M109 S200 ; wait for extruder temp
G28 W ; home all without mesh bed level
G80 ; mesh bed leveling
G92 E0.0 ; reset extruder distance position
; End of G-code from CURA
; Manually copied G-code from PRUSA to ensure oozing etc from the MMU Start G-code - not sure though if this is at the correct space and has the correct content.
M203 E100
M92 E140
G1 Z0.250 F7200.000
G1 X50.0 E80.0 F1000.0
G1 X160.0 E20.0 F1000.0
G1 Z0.200 F7200.000
G1 X220.0 E13 F1000.0
G1 X240.0 E0 F1000.0
;G1 E-4 F1000.0
G92 E0.0
; End of manually copied G-code from PRUSA
; Start of G-code from CURA - no further PRUSA code added from here onwards
G1 Y-3.0 F1000.0 ; go outside print area
G1 X60.0 E9.0 F1000.0 ; intro line
G1 X100.0 E21.5 F1000.0 ; intro line
G92 E0.0 ; reset extruder distance position
;LAYER_COUNT:481
;LAYER:0
M107
G0 F3600 X105.003 Y111.333 Z0.15
;TYPE:SKIRT
G1 F1800 X105.054 Y111.287 E0.00291
G1 X106.369 Y110.228 E0.07451
G1 X106.41 Y110.197 E0.07669
G1 X107.947 Y109.163 E0.15525
G1 X107.982 Y109.142 E0.15698
G1 X109.82 Y108.079 E0.24702
G1 X109.857 Y108.058 E0.24882
G1 X113.653 Y106.211 E0.42784
G1 X113.7 Y106.191 E0.43001
G1 X117.561 Y104.703 E0.60548
G1 X117.608 Y104.687 E0.60758
G1 X122.276 Y103.319 E0.81386
G1 X122.314 Y103.31 E0.81552
G1 X127.724 Y102.097 E1.05064
Re: G-Code start problems (extrusion is starting too late) after slicing with CURA
This line is your problem in your start code:
;G1 E-4 F1000.0 - "Manually inserted into CURA code below"
Get rid of that one. It's sucking the filament into the nozzle after the purge by 4mm and then never returning it when it starts printing.
Edit: after re-reading your post, I'm not quite sure what exactly you are putting into cura. In Slic3r, that line is what causes the issue.
Re: G-Code start problems (extrusion is starting too late) after slicing with CURA
Sorry, that is not correct. He commented out that line.
The real issue is in the purge line code:
G1 X50.0 E80.0 F1000.0
G1 X160.0 E20.0 F1000.0
G1 Z0.200 F7200.000
G1 X220.0 E13 F1000.0
G1 X240.0 E0 F1000.0
But you are still in absolute coordinates (M82). That means "move in X and forward extruder to coordinate 80", then 20, then 13, then 0 (releasing most of the pressure in the nozzle in the final part without additional E move). In other words, after the first part of the purge line you are going back instead of only reducing the pressure (line 3 only lowers the nozzle a bit to account for the reduced pressure). Switch back to relative before you do that and you should be fine. I don't know if you have to reenable M82 in the very end or if Cura does it automatically (you might notice that in the model GCODE E values are constantly increasing = absolute).
Or you can change the lines to:
G1 X50.0 E80.0 F1000.0
G1 X160.0 E100.0 F1000.0
G1 Z0.200 F7200.000
G1 X220.0 E113 F1000.0
G1 X240.0 F1000.0
After fully waking up...make sure you keep the G92 E0.0 in the end. That zeros the extrusion length. If you removed it, on the first line of the real print the printer would basically undo all the previous extruder moves.