Slicer setup¶

Every slicer needs three things for auto-eject:

	What	Why
1	Object labels in the G-code	`AUTO_EJECT` plans the sweep from the part outlines
2	Start G-code with `AUTO_EJECT_GUARD` and `EJECT_PURGE`	Never print on old parts. A purge pellet the sweep can remove
3	End G-code with `AUTO_EJECT ... HOME=1`	Runs after your end macro, which retracts the filament while the nozzle is still hot

The examples call your start macro PRINT_START and your end macro PRINT_END. Use the names your configuration uses (START_PRINT, DEMON_START, …).

Easier: the web page's Blade and setup tab has a card, In your slicer, with these lines ready to copy and your printer's own end macro already in them, found in its newest file or its config.

The In your slicer card in the web page

Guard. AUTO_EJECT_GUARD goes first. It stops the print, or ejects first, if parts from an interrupted print may still be on the bed (recovery.md).

Purge. EJECT_PURGE runs after PRINT_START, so turn off the purge line inside your start macro (KAMP LINE_PURGE, DEMON purge line, Voron purge). Otherwise you get both.

Temperature placeholders at a glance¶

Slicer	Bed (first layer)	Nozzle (first layer)
OrcaSlicer	`[bed_temperature_initial_layer_single]`	`[nozzle_temperature_initial_layer]`
PrusaSlicer / SuperSlicer	`[first_layer_bed_temperature]`	`[first_layer_temperature]`
Cura	`{material_bed_temperature_layer_0}`	`{material_print_temperature_layer_0}`

OrcaSlicer¶

Object labels: Process → Others → G-code output: turn on Label objects and Exclude objects.

Printer settings → Machine G-code → Machine start G-code

AUTO_EJECT_GUARD
M104 S0
M140 S0
PRINT_START BED=[bed_temperature_initial_layer_single] EXTRUDER=[nozzle_temperature_initial_layer]
EJECT_PURGE

Machine end G-code

PRINT_END
AUTO_EJECT HEIGHT=[max_layer_z] HOME=1

M104 S0 / M140 S0 before the macro stop Orca from adding its own heat-and-wait commands. HEIGHT=[max_layer_z] passes the print height, so stencils and other thin prints are recognised and left alone. AUTO_EJECT goes after the end macro: end macros retract the filament, which Klipper refuses once the nozzle has cooled, and HOME=1 homes again around the parts if the end macro turned the motors off (integration.md).

To cool the bed to another temperature for some materials (cool_temps), pass the material too: AUTO_EJECT HEIGHT=[max_layer_z] MATERIAL=[filament_type] HOME=1.

PrusaSlicer / SuperSlicer¶

Object labels: Print Settings → Output options → Label objects: Firmware-specific (with G-code flavor Klipper). Older SuperSlicer builds only write comments. If so, use Moonraker object processing.

Printer Settings → Custom G-code → Start G-code

AUTO_EJECT_GUARD
M104 S0
M140 S0
PRINT_START BED=[first_layer_bed_temperature] EXTRUDER=[first_layer_temperature]
EJECT_PURGE

End G-code

PRINT_END
AUTO_EJECT HEIGHT=[max_layer_z] HOME=1

Cura¶

Machine Settings → Printer → Start G-code

AUTO_EJECT_GUARD
PRINT_START BED={material_bed_temperature_layer_0} EXTRUDER={material_print_temperature_layer_0}
EJECT_PURGE

Using these variables stops Cura from inserting its own heating commands.

End G-code

PRINT_END
AUTO_EJECT HOME=1

Object labels: see the next section.

Cura and slicers without native labels¶

Moonraker can add the labels for you. In moonraker.conf:

[file_manager]
enable_object_processing: True

Restart Moonraker. Uploaded files that contain object tags are then rewritten with Klipper's EXCLUDE_OBJECT commands. It works with any slicer that marks objects in comments.

Other slicer settings¶

Skirt: turn it off, or keep it inside the area of the parts. A skirt is too thin for the blade to catch.
Brim: fine. It comes away with the part.
Without labels at all: use STRATEGY=full_width, or set no_objects_action: "full_width".
G-code thumbnails: not needed for the eject, but the web page and the farm show each file with its picture when the slicer puts one in (where to turn them on).

Prints you will remove by hand¶

Prints lower than min_part_height (2 mm), such as stencils, are left on the bed automatically (thin parts). For anything else, keep a second printer profile, or swap the end G-code, without AUTO_EJECT:

PRINT_END

The same file then works on a printer without the blade fitted.

DEMON Klipper Essentials¶

DEMON_END retracts the filament, so AUTO_EJECT goes after it (integration.md):

DEMON_END
AUTO_EJECT HEIGHT=[max_layer_z] HOME=1

In the start G-code, keep DEMON's lines exactly as DEMON gives them and add nothing: with DEMON, AUTO_EJECT_GUARD runs in DEMON's _CUSTOM_PRE_START hook, because DEMON stops the printer when something runs before DEMON_START for more than a few seconds. install.sh sets it up, or ~/klipper-auto-eject/install.sh --demon on a printer that has auto-eject already (integration.md). The web page's In your slicer card finds DEMON by itself and says the same.

Check the G-code¶

After slicing, open the G-code and search for:

Look for	Means
`EXCLUDE_OBJECT_DEFINE`	Object labels are in the file
`EJECT_PURGE`	The pellet purge is in the start G-code
`AUTO_EJECT` after your end macro	The eject runs after the print

If the labels are missing and Moonraker object processing is on, check the file in Mainsail or Fluidd: the Exclude objects button appears during the print once it has been processed.

Back-to-back printing¶

Queue jobs from Mainsail or Fluidd and turn on Moonraker's automatic transition. Moonraker describes this option as meant for machines that clear the build area themselves:

[job_queue]
load_on_startup: False
automatic_transition: True
job_transition_delay: 5

Don't put AUTO_EJECT in job_transition_gcode: Moonraker runs it only between two queued jobs, so the last print of the queue would stay on the bed.