sndcut is a program the generates LP records from audio files - it generates either a SVG file for laser cutting or g-code for a 3-axis cnc mill. Its implementation is inspired by https://github.com/mitsuhito/CuttingRecordGenerator but it does some additional things (e.g.: RIAA equalization) to improve sound quality of the records.

Usage

Using sndcut is very simple. To generate a record you simply have to invoke it with an audio file (usually a wav or ogg file since mp3 is not supported. Have a look here for supported file types.

The following examples will give you and idea of the basic usage. But you should be aware that you can tweak following parameters:

• The diameter of the record in mm
• The sampling rate in Hz of the resulting record. Automatic resampling will be done if it differs from the input file sampling rate. Setting this parameter to zero will adopt the sampling rate of the input file
• Target RPM of the record
• The maximum amplitude in mm
• The space in between lines in mm
• The inner margin of the record in mm
• The outer margin of the record in mm
• The center hole diameter in mm
• The stroke width in the svg file in mm
• The DPI of the laser cutter
• RIAA equalization
• Audio normalization
• Several options for g-code generation

Usage: sndcut [options] <audioFile>

Options:
  -d [ --diameter ] arg (=302)          The diameter of the record in mm
  -r [ --rate ] arg (=0)                The sampe rate in Hz of the resulting 
                                        record. Automatic resampling will be 
                                        done if it differs from the input file 
                                        sample rate. Setting this parameter to 
                                        zero will adopt the sample rate of the 
                                        input file.
  -m [ --rpm ] arg (=33.5)              Target RPM of the record
  -a [ --amplitude ] arg (=0.14999999999999999)
                                        The maximum amplitude in mm
  -s [ --spacing ] arg (=0.5)           The space in between lines in mm
  -i [ --inner ] arg (=120.65000000000001)
                                        The inner margin of the record in mm
  -o [ --outer ] arg (=5)               The outer margin of the record in mm
  -c [ --center ] arg (=7.2400000000000002)
                                        The center hole diameter in mm
  -t [ --stroke ] arg (=0.025000000000000001)
                                        The stroke width in the svg file in mm
  -p [ --dpi ] arg (=1200)              The machine DPI which is used to limit 
                                        the detail in the record. 
  -n [ --enable-normalize ] arg (=1)    Enable audio normalization
  -f [ --enable-riaafilter ] arg (=1)   Enable inverse RIAA equalization
  -g [ --gcode ]                        Output gcode instead of svg. PLEASE 
                                        NOTE: you have to specify all numeric 
                                        gcode arguments as positive numbers 
                                        even when convention dictates a 
                                        negative number (like for depths that 
                                        go below the target surface)
  --gmc arg (=1)                        Set the diameter of the milling cutter 
                                        (not the drag knife!)
  --gcf arg (=1100)                     Set the gcode cut feed rate
  --gpf arg (=1100)                     Set the gcode plunge feed rate
  --ggc arg (=5)                        Set the gcode cut feed rate for the 
                                        groove
  --ggp arg (=5)                        Set the gcode plunge feed rate for the 
                                        groove
  --gmd arg (=1.7)                      Set the gcode material depth
  --ggd arg (=0.11)                     Set the gcode groove depth
  --gsd arg (=10)                       Set the gcode save depth
  --gmi arg (=1)                        Set the gcode material depth increment
  --ggi arg (=0.10000000000000001)      Set the gcode groove depth increment
  -h [ --help ]                         Produce help message

Examples

In this repository included are 3 pregenerated examples. All were generated from the same wav file (imperial.wav). Please note that sndcut does automatic resampling of the audio data (default: 8000hz)

Command line used to generate imperial_short.svg for a laser cutter:

sndcut imperial.wav > imperial_short.svg

Command line used to generate imperial_long.svg for a laser cutter:

# a diameter of 300 millimeters
sndcut -d300 imperial.wav > imperial_long.svg

Command line used to generate imperial.nc.gz for a cnc mill:

# a 2mm milling cutter, a cut rate of 100mm/s, a plunge rate of 100mm/s, a material depth of 4mm, a groove depth of 0.1mm, a save depth of 10mm, a depth increment of 1mm for cutting and a depth increment of 0.1mm for the groove.
sndcut -r 44100 -p 10000 -g --gmc 2 --gcf 100 --gpf 100 --gmd 4 --ggd 0.1 --gsd 10 --gmi 1 --ggi 0.1 imperial.wav > imperial.nc
gzip imperial.nc

Laser Cutting

The material I used is 5mm acrylic. I used a Epilog Legend 36Ext (60W) with following settings:

• Green lines - Speed: 12%, Power: 100%
• Blue lines - Speed: 10%, Power: 3%

If you happen to own a Epilog Legend 36Ext laser cutter you can use the ".cut" files included in the examples folder. Those files have all settings done and are ready to laser with Ctrl-Cut

Packages

There are linux packages available for following distributions:

• Fedora 20
• OpenSUSE (13.1, 13.2, Factory)
• Debian 7.0
• Ubuntu (14.04, 14.10)
• Arch

Download

Download Arch Linux

Build

You'll need to install the development version of following libraries:

• boost_program_options
• libsamplerate
• libsndfile
• cmake

After you installed the dependencies all you have to do is type

./build_deps.sh
make

Aside from linux it has been reported to build on Mac OS X.