Q: Oh cool, a new RepRap slicer?

A: Yes.

Slic3r

What's it?

Slic3r is an STL-to-GCODE translator for RepRap 3D printers, aiming to be a modern and fast alternative to Skeinforge.

See the project homepage at slic3r.org for more information.

What language is it written in?

Proudly Perl, with some parts in C++. If you're wondering why Perl, see http://xkcd.com/224/

What's its current status?

Slic3r current key features are:

• multi-platform (Linux/Mac/Win) and packaged as standalone-app with no dependencies required;
• easy configuration/calibration;
• read binary and ASCII STL files;
• powerful command line interface;
• easy GUI
• multiple infill patterns, with customizable density and angle;
• retraction;
• skirt;
• infill every N layers (like the "Skin" plugin for Skeinforge);
• detect optimal infill direction for bridges;
• save configuration profiles;
• center print around bed center point;
• multiple solid layers near horizontal external surfaces;
• ability to scale, rotate and duplicate input object;
• customizable initial and final GCODE;
• use different speed for bottom layer and perimeters.

Experimental features include:

• generation of G2/G3 commands for native arcs;
• G0 commands for fast retraction.

Roadmap includes the following goals:

• output some statistics;
• support material for internal perimeters;
• new and better GUI;
• cool;
• other fill patterns.

Is it usable already? Any known limitation?

Sure, it's very usable. Remember that:

• it doesn't currently support single-walled parts (such as thin calibration objects);
• it doesn't generate support material;
• it only works well with manifold models (check them with Meshlab or Netfabb or http://cloud.netfabb.com/).

How to install?

It's very easy. See the project homepage for instructions and links to the precompiled packages.

Can I help?

Sure! Send patches and/or drop me a line at aar@cpan.org. You can also find me in #reprap on FreeNode with the nickname Sound.

What's Slic3r license?

Slic3r is dual-licensed under the Perl Artistic License and the AGPLv3. The author is Alessandro Ranellucci (me).

How can I invoke slic3r.pl using the command line?

Usage: slic3r.pl [ OPTIONS ] file.stl

    --help              Output this usage screen and exit
    --save <file>       Save configuration to the specified file
    --load <file>       Load configuration from the specified file
    -o, --output        File to output gcode to (default: <inputfile>.gcode)
    
  Printer options:
    --nozzle-diameter   Diameter of nozzle in mm (default: 0.5)
    --print-center      Coordinates of the point to center the print around 
                        (default: 100,100)
    --use-relative-e-distances
                        Use relative distances for extrusion in GCODE output
    --extrusion-axis    The axis used for extrusion; leave empty to disable extrusion
                        (default: E)
    --z-offset          Additional height in mm to add to vertical coordinates
                        (+/-, default: 0)
    --gcode-arcs        Use G2/G3 commands for native arcs (experimental, not supported
                        by all firmwares)
    --g0                Use G0 commands for retraction (experimenta, not supported by all
                        firmwares)
    
  Filament options:
    --filament-diameter Diameter in mm of your raw filament (default: 3)
    --extrusion-multiplier
                        Change this to alter the amount of plastic extruded. There should be
                        very little need to change this value, which is only useful to 
                        compensate for filament packing (default: 1)
    --temperature       Extrusion temperature, set 0 to disable (default: 200)
    
  Speed options:
    --travel-speed      Speed of non-print moves in mm/sec (default: 130)
    --perimeter-speed   Speed of print moves for perimeters in mm/sec (default: 30)
    --small-perimeter-speed
                        Speed of print moves for small perimeters in mm/sec (default: 30)
    --infill-speed      Speed of print moves in mm/sec (default: 60)
    --solid-infill-speed Speed of print moves for solid surfaces in mm/sec (default: 60)
    --bridge-speed      Speed of bridge print moves in mm/sec (default: 60)
    --bottom-layer-speed-ratio
                        Factor to increase/decrease speeds on bottom 
                        layer by (default: 0.3)
    
  Accuracy options:
    --layer-height      Layer height in mm (default: 0.4)
    --first-layer-height-ratio
                        Multiplication factor for the height to slice and print the first
                        layer with (> 0, default: 1)
    --infill-every-layers
                        Infill every N layers (default: 1)
  
  Print options:
    --perimeters        Number of perimeters/horizontal skins (range: 1+, 
                        default: 3)
    --solid-layers      Number of solid layers to do for top/bottom surfaces
                        (range: 1+, default: 3)
    --fill-density      Infill density (range: 0-1, default: 0.4)
    --fill-angle        Infill angle in degrees (range: 0-90, default: 0)
    --fill-pattern      Pattern to use to fill non-solid layers (default: rectilinear)
    --solid-fill-pattern Pattern to use to fill solid layers (default: rectilinear)
    --start-gcode       Load initial gcode from the supplied file. This will overwrite
                        the default command (home all axes [G28]).
    --end-gcode         Load final gcode from the supplied file. This will overwrite 
                        the default commands (turn off temperature [M104 S0],
                        home X axis [G28 X], disable motors [M84]).
  
  Retraction options:
    --retract-length    Length of retraction in mm when pausing extrusion 
                        (default: 1)
    --retract-speed     Speed for retraction in mm/sec (default: 40)
    --retract-restart-extra
                        Additional amount of filament in mm to push after
                        compensating retraction (default: 0)
    --retract-before-travel
                        Only retract before travel moves of this length (default: 2)
    --retract-lift      Lift Z by the given distance in mm when retracting (default: 0)
   
   Skirt options:
    --skirts            Number of skirts to draw (default: 1)
    --skirt-distance    Distance in mm between innermost skirt and object 
                        (default: 6)
    --skirt-height      Height of skirts to draw (expressed in layers, default: 1)
   
   Transform options:
    --scale             Factor for scaling input object (default: 1)
    --rotate            Rotation angle in degrees (0-360, default: 0)
    --duplicate-x       Number of items along X axis (1+, default: 1)
    --duplicate-y       Number of items along Y axis (1+, default: 1)
    --duplicate-distance Distance in mm between copies (default: 6)
  
  Flow options (advanced):
    --extrusion-width-ratio
                        Calculate the extrusion width as the layer height multiplied by
                        this value (> 0, default: calculated automatically)
    --bridge-flow-ratio Multiplier for extrusion when bridging (> 0, default: 1)
    --overlap-ratio     Overlap between extrusion threads expressed as a ratio over extrusion 
                        width (> 0, default: 0.15)

If you want to change a preset file, just do

slic3r.pl --load config.ini --layer-height 0.25 --save config.ini

If you want to slice a file overriding an option contained in your preset file:

slic3r.pl --load config.ini --layer-height 0.25 file.stl