Slic3r/PrusaSlicer and Chroma Setup

Application Preferences:  Ensure Mode is set to Expert

Printer Settings > General

Set Extruders to 4 (settings from Extruder 1 will be copied to Extruders 2–4)

Change Retraction when tool is disabled settings for Extruders 1–4

Set Length to 0

Set Extra length on restart to 0

Dual-extruders: ensure that Extruder 2 settings match Extruder 1 settings (particularly Extruder offset being 0 and 0)

Printer Settings > Custom GCode

Dual-extruders: ensure your Start GCode and end GCode don’t include any nozzle priming or temperature settings for extruders other than T0      

Print Settings > Skirt and Brim

Set Loops (minimum) to 0

Set Minimum extrusion length to 0

Print Settings > Output Options

Ensure Complete individual objects is unchecked

Save this print configuration for future re-use

Plater

Select the print and printer configurations that were just saved

Select the same filament configuration in all four extruder drop-downs

Load in ONE of the STLs you would like to print, rather than all of them

Double-click on the STL preview on the bed

Click Load part… and select the rest of the STLs

For each STL, select the extruder to be used for that STL

Click OK when all STLs have been mapped to an extruder. That’s it! Click Export Gcode… and you’re ready to load the file into Chroma.

For Slic3r Prusa Edition, there is a G4 ;wait configured in the END GCODE as a default. Chroma will provide an error as it is expecting a value after the G4 command (Chroma does helpfully tell you a recommend value). To avoid this, you'll need to either delete this line from your end sequence or modify it to take a numeric value. 

Please ensure Print setting/Multiple Extruders/Wipe tower is not checked off as Chroma will produce a wipe tower for you that is compatible.

We would also suggest reviewing the default start sequence as there is a flow rate modifier that may cause issues with pings:

M221 S{if layer_height==0.05}100{else}95{endif}

This command will get processed at slice-time and will result in the command 'M221 S95'. Chroma will not take this command into account and can cause issues with low pings.

To fix this issue, please remove this line from the starting GCode and lower the extrusion multiplier to compensate.

If you've sliced your project and the transition tower is unreasonably large, please check that the following settings are adjusted:

Please ensure that all the min/max layer heights are the same across all 4 extruders.

Check that your Contact Z distance is the same as your layer height.

Check that you've disabled Slic3r's wipe tower.

Lastly, please turn off Variable Layer Heights.

For users who would like to use Slic3r's features without having to process the file through Chroma, there's a user-made plugin called P2PP that creates the necessary files directly in Slic3r. For more information, please see here.