scholtzan / cura-multicolor-single-extruder Goto Github PK

Hi and first of all thanks for providing this script!

The Issue: after every extruder has printed its skirt/brim/raft (have only tried skirt and prime tower), Cura produces a prime blob after the tool change. The tool change is gone, it has been converted to a filament change, but the surrounding behaviour of Cura hasn't. So cura extrudes 16mm of filament every time the filament changes after brim has been printed. It does this at the position where the printhead was last, before the tool change (now filament change). Normally that would be at the print head parking position, the perfect spot for a prime blob. But in this case, the last position of the printhead is inside the print. Even if you're attentive and careful, this blob can easily destroy your print and has done so one some of my testprints. What I've done is to make the script move out of the print before filament change and then manually edit the Gcode so when that E16 command happens, the printhead is still outside of the print. Also, if the Nozzle has to heat up, it will do so not on top of the print, oozing filament, but in the safe zone.

The option "prime blob" is not accessible in preferrences and from what I've read, Cura devs deem the user incapable of making such adjustments responsibly and therefore are hard-hiding certain options. Ultimaker/Cura#6513
The prime blob still happens when there is a prime tower, then it happens in the prime tower, where t will be an obstacle for the nozzle to bump into, losing steps, failing the print.

So here's my measly modd attempt at your script:

filament_change = "M600"

filament_change = "G0 F8100 X10 Y10 Z30 \nM600"

that's the only line I changed and it already helps a bit.

Here's the Gcode output after Brim has been printed:

---

...
G92 E0
G0 F8100 X10 Y10 Z30
M600 E-20.00 L100.00 X0.00 Y0.00 Z30.00 ; Generated by FilamentChangeOnToolChange plugin
G92 E0
M104 T2 S175
M105
M109 S215
M107
;MESH:buchstaben.obj
G0 F8100 X113.298 Y111.696 Z0.7
M104 S210
M204 S3000
;TYPE:WALL-OUTER
G1 F600 Z0.5
G1 F1200 E16
G1 F1276.6 X113.31 Y111.545 E16.00592
G1 F1376.1 X113.52 Y111.487 E16.01382
...

---

Afterwards, I manual edit to this:

---

...
G92 E0
G0 F8100 X10 Y10 Z10
M600 E-20.00 L100.00 X0.00 Y0.00 Z30.00 ; Generated by FilamentChangeOnToolChange plugin
G92 E0

M104 T2 S175
M105
M109 S215
M107

G1 F1200 E16
G0 F8100 X10 Y10 Z10

;MESH:buchstaben.obj
G0 F8100 X113.298 Y111.696 Z0.7
M104 S210
M204 S3000

;TYPE:WALL-OUTER
G1 F600 Z0.5

G1 F1276.6 X113.31 Y111.545 E16.00592
G1 F1376.1 X113.52 Y111.487 E16.01382
...

---

further Info: Cura 5.0.0, Ender 3 S1 pro

Sadly learning python is not an option for me right now. You'd need to have a little buffer of some sort and look for that evil "G1 F1200 E16" line and put it some lines earlier. Then empty the buffer into Gcode and terminate. This is gonna neccessitate adjustment possibilities for the user (probably). Flow rate might be profile dependent, haven't checked.

I'd also like to have the option to make the machine go into pause, My printer just reads the filament sensor, sees filament_there==true and just continues to print regardless of any user input. For later filament changes that is really inconvenient behaviour.

Anyways, love what you're doing, keep up the good work!
Moritz