Slicer4RTN

RTN stands for Rotating Tilted Nozzle, a 4-axis 3D printer.

Slicing4RTN is an Open Source implementation of a conic slicing procedure as invented by ZHAW (Elspass, Jaeger, Wuethrich, Gubser, Bos and Holdener) and became known as part of their RotBot announcement in 2021/01.
This software has been independently developed yet is comparable to the solution of ZHAW.

Conic Slicing for Rotating Tilted Nozzle (RTN) / 4 Axis lays out more details of the slicing procedure and its application;
and Slicer4RTN contains a more thorough description of the features and details how to use slicer4rtn.

NOTE: The software is in a very experimental state and defaults and settings might change during this early stage of development - please use caution when running the G-code on your 3-, 4- or 5-axis 3D printer, don’t do this unattended.

Limitations

In its current state only slices in a single “conic mode” per model, either outside-cone printing or inside-cone printing (change with --mode=..)
which means, only a single overhang reference is supported: conic slicing allows overhangs to be printed without support structure given they point away or to a central conic center;
multiple centers are not yet supported which would require sub-volume segmenting and treat each sub-volume printed in its own mode.

A future version of Slicer4RTN might segment volumes and support multiple conic centers and more complex overhang slicing - this is why this software is released as Open Source to help to push this development.

Supported Platforms

Linux Ubuntu/Debian, tested on Ubuntu 20.04 LTS

Updates

0.6.0: $efa multiplier adjusted, —rot-revolve=0 (new default, unlimited revolv), —rot-revolve=1 (single revolv) does performs smart rotate-around to immitate continenous rotation
0.5.2: —rotate, —scale and —translate added for pre-processing model
0.5.1: experimentally support .off, .obj, both more compact than .stl
0.5.0: fixing levelModel() affected CuraEngine/cura-slicer, version bump
0.4.8: support of start-gcode and end-gcode
0.4.7: cleaner X Y Z output
0.4.6: adding support for ‘cura-slicer’ (CuraEngine wrapper https://github.com/Spiritdude/Cura-CLI-Wrapper)
0.4.5: fixing config load for slic3r & prusa-slicer
0.4.2: CuraEngine 4.4.x & CuraEngineLegacy (15.10) experimental support added
0.4.0: supporting ~/.config/slicer4rtn/slicer4rtn.ini with new defaults
0.3.4: rot_revolv=1 better $rot calculation (rot_revolv=0 untested)
0.3.1: changing rot-offset 0 => -90
0.3.0: version bump with various cleanups, more consistent settings, —inter-steps added
0.2.6: diverse new settings: rot_gcode, rot_offset, rot_revolv, tilt_gcode and layer-height which is computed for core-slicer
0.2.5: added main $efa multiplier depends on angle, not yet sure if it’s correct
0.2.4: making arguments for core slicer easier, —slicer.= as well —= works (better for print3r integration)
0.2.3: simplifying code, extrusion interpolation still off (needs reworking)
0.2.0: changing extrusion calculation, better apprx., flow_rate => erate
0.1.1: properly re-offset G-code output from slic3r and prusa-slicer as it centers model, early support for prusa-slicer
0.1.0: new —slicer.key=val added, added —zoff=val to re-adjust zoffset in final G-code
0.0.5: added —axis=3, 4 or 5 to create for 3-, 4- or 5-axis G-code 3d-printer, added —angle=45 to change angle of cone
0.0.4: added —mode=outside or inside to reverse order for inside/outside-cone printing
0.0.3: moving stl2rtn and gcodertn into slicer4rtn
0.0.2: bug fixed, much better G-gcode output, viewable by Cura
0.0.1: first functional version, various bugs

Download

% git clone https://github.com/Spiritdude/Slicer4RTN
% cd Slicer4RTN/

Installation

% make requirements

if you want to install slicer4rtn system-wide:

% make install

which installs the app and sane defaults in /usr/share/slicer4rtn/ but edit your personal settings per core slicer
in ~/.config/slicer4rtn/ as those will not be overwritten in future upgrades with the same filename as in /usr/share/slicer4rtn/.

Usage

% ./slicer4rtn
USAGE Slicer4RTN 0.6.0: [<opts>] <file.stl> ...
   options:
      -v or --verbose      increase verbosity
      --version            display version and exit
      -k or --keep         keep all temporary files (temp.stl, temp.gcode)
      --rotate=<x,y,z>     rotate model
      --translate=<x,y,z>  translate model
      --scale=<s>          scale uniform
      --scale=<x,y,z>      scale individually
      --recenter           recenter model X- & Y-wise
      --subdivide=<n>      set midpoint subdivisions (default: 2)
      --mode=<mode>        set cone mode, either 'outside' or 'inside' (default: 'outside')
      --output=<fname>     override default naming convention file.stl -> file.gcode
      --axis=<axis>        set axis count of printer: 3, 4 or 5 (default: 4)
      --angle=<angle>      set angle of cone (default: 45)
      --center=<cx,cy>     set conic slicing center (default: 0,0)
      --bed-center=<cx,cy> set bed-enter, only affects output G-code (default: 100,100)
      --layer-height=<z>   set conic layer height (default: 0.2)
      --rot-gcode=<v>      set G-code symbol for rotation (default: A)
      --rot-revolv=<mode>  set rotation revolution, 0 = unlimited, 1 = once (default: 0)
      --rot-offset=<a>     set rotation offset (default: -90)
      --rot-fixed=<angle>  set fixed rotation angle, usable if --axis=3 but 4-axis or 5-axis printer is target
      --tilt-gcode=<v>     set G-code symbol for tilt for 5-axis operation (default: B)
      --zoff=<v>           set z-offset, will be added to G1 ... Z<v>
      --erate=<f>          set extrusion rate (multiplier, default: 1)
      --efmin=<v>          set extrusion factor minimum, (default: 0.01)
      --efmax=<v>          set extrusion factor maximum, (default: 3)
      --inter-steps=<n>    set interpolation steps per mm (default: 2)
      --motion-minz=<v>    set minimum Z level for motion (without extrusion) (default: 0.2)
      --max-speed=<s>      set maximum speed (default: 0)
      --slicer=<slicer>    set core slicer slic3r, prusa-slicer, CuraEngine{Legacy}, cura-slicer, mandoline (default: 'slic3r')
      --start-gcode=...    set start gcode (disables core slicer's start-gcode)
      --end-gcode=...      set end gcode (disables core slicer's end-gcode)
      --slicer.<k>=<v>     add additional slicer arguments, e.g. --slicer.infill-density=0
      --<k>=<v>            all other arguments not for slicer4rtn will be passed to the core slicer (slic3r)
   examples:
      slicer4rtn sphere.stl
      slicer4rtn overhang.stl --output=sample.gcode
      slicer4rtn overhang.stl --axis=5 --output=sample.gcode
      slicer4rtn overhang.stl --axis=3 --output=sample-belt-printer.gcode --fill-density=5
      slicer4rtn model-6.stl --angle=25 --subdivide=5

Todo

improve extrusion accuracy (needs to be tested more thoroughly)
more core slicer support
- Slic3r 1.2.x (slic3r): gives reliable results for now
- Prusa Slicer 2.x (prusa-slicer): it makes assumptions of printability, e.g. an inverse conic mapped cube creates “Empty layers detected, the output would not be printable”, and fails to be sliced; not recommended
- Cura Engine 4.x (CuraEngine): gives very good results, but is tedious to configure without GUI
  - Cura CLI Wrapper (cura-slicer): easier to use than CuraEngine
- Cura Engine Legacy 15.10 (CuraEngineLegacy): gives good results as well
- Mandoline (Python) (mandoline): creates faulty G-code for now, struggles with pointy structures after inverse conic mapping, not recommended yet (but might become the most relevant slicer in the future of slicer4rtn)
port to Python: larger developer pool than with Perl (must be fully compatible with its Perl version) in order to push development like
support for Multi Cone-Mode/Centers printing, requires overhang recognition and sub-volume segmentation

3-, 4- and 5-axis Printing

3-axis: use --angle=25 or so, and preview the G-code before you print, see 90 deg Overhangs without Support Structure with Non-Planar Slicing on 3-axis Printer
4-axis: not yet tested in physical, only as simulation
- RotBot: use --rot-gcode=U, --rot-revolv=0 and --rot-offset=0 (untested)
5-axis: not yet tested in physical, only as simulation

See Rotating Tilted Nozzle for more details.