Slicers

This document provides some tips for configuring a "slicer" application for use with Kalico. Common slicers used with Kalico are Slic3r, Cura, Simplify3D, etc.

Set the G-Code flavor to Marlin

Many slicers have an option to configure the "G-Code flavor". Most modern slicers nowadays have a "Klipper" G-Code flavor that works best for Kalico. "Marlin" also should work well with Kalico if the "Klipper" flavor is not available. The "Smoothieware" setting also works well with Kalico.

Kalico gcode_macro

Slicers will often allow one to configure "Start G-Code" and "End G-Code" sequences. It is often convenient to define custom macros in the Kalico config file instead - such as: [gcode_macro START_PRINT] and [gcode_macro END_PRINT]. Then one can just run START_PRINT and END_PRINT in the slicer's configuration. Defining these actions in the Kalico configuration may make it easier to tweak the printer's start and end steps as changes do not require re-slicing.

See sample-macros.cfg for example START_PRINT and END_PRINT macros.

See the config reference for details on defining a gcode_macro.

Large retraction settings may require tuning Kalico

The maximum speed and acceleration of retraction moves are controlled in Kalico by the max_extrude_only_velocity and max_extrude_only_accel config settings. These settings have a default value that should work well on many printers. However, if one has configured a large retraction in the slicer (eg, 5mm or greater) then one may find they limit the desired speed of retractions.

If using a large retraction, consider tuning Kalico's pressure advance instead. Otherwise, if one finds the toolhead seems to "pause" during retraction and priming, then consider explicitly defining max_extrude_only_velocity and max_extrude_only_accel in the Kalico config file.

Do not enable "coasting"

The "coasting" feature is likely to result in poor quality prints with Kalico. Consider using Kalico's pressure advance instead.

Specifically, if the slicer dramatically changes the extrusion rate between moves then Kalico will perform deceleration and acceleration between moves. This is likely to make blobbing worse, not better.

In contrast, it is okay (and often helpful) to use a slicer's "retract" setting, "wipe" setting, and/or "wipe on retract" setting.

Do not use "extra restart distance" on Simplify3d

This setting can cause dramatic changes to extrusion rates which can trigger Kalico's maximum extrusion cross-section check. Consider using Kalico's pressure advance or the regular Simplify3d retract setting instead.

Disable "PreloadVE" on KISSlicer

If using KISSlicer slicing software then set "PreloadVE" to zero. Consider using Kalico's pressure advance instead.

Disable any "advanced extruder pressure" settings

Some slicers advertise an "advanced extruder pressure" capability. It is recommended to keep these options disabled when using Kalico as they are likely to result in poor quality prints. Consider using Kalico's pressure advance instead.

Specifically, these slicer settings can instruct the firmware to make wild changes to the extrusion rate in the hope that the firmware will approximate those requests and the printer will roughly obtain a desirable extruder pressure. Kalico, however, utilizes precise kinematic calculations and timing. When Kalico is commanded to make significant changes to the extrusion rate it will plan out the corresponding changes to velocity, acceleration, and extruder movement - which is not the slicer's intent. The slicer may even command excessive extrusion rates to the point that it triggers Kalico's maximum extrusion cross-section check.

In contrast, it is okay (and often helpful) to use a slicer's "retract" setting, "wipe" setting, and/or "wipe on retract" setting.

START_PRINT macros

When using a START_PRINT macro or similar, it is useful to sometimes pass through parameters from the slicer variables to the macro.

In Cura, to pass through temperatures, the following start gcode would be used:

START_PRINT BED_TEMP={material_bed_temperature_layer_0} EXTRUDER_TEMP={material_print_temperature_layer_0}

In slic3r derivatives such as PrusaSlicer and SuperSlicer, the following would be used:

START_PRINT EXTRUDER_TEMP=[first_layer_temperature] BED_TEMP=[first_layer_bed_temperature]

Also note that these slicers will insert their own heating codes when certain conditions are not met. In Cura, the existence of the {material_bed_temperature_layer_0} and {material_print_temperature_layer_0} variables is enough to mitigate this. In slic3r derivatives, you would use:

M140 S0
M104 S0

before the macro call. Also note that SuperSlicer has a "custom gcode only" button option, which achieves the same outcome.

An example of a START_PRINT macro using these paramaters can be found in config/sample-macros.cfg