Difference between revisions of "File formats"

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(What file formats does Carbide Create save?)
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* http://pypi.python.org/pypi/pyautocad/
* http://pypi.python.org/pypi/pyautocad/
* lack of units in DXFs: https://forums.autodesk.com/t5/autocad-forum/dxf-units/td-p/2077502
* lack of units in DXFs: https://forums.autodesk.com/t5/autocad-forum/dxf-units/td-p/2077502
* STEP https://www.iso.org/fr/standard/72237.html

Revision as of 06:50, 26 September 2021

What are the kinds of graphic file formats?

Files for graphics output are divided into two notable categories:

  • pixel --- short for picture element, these are files which are made up of dots which are either on/off, shades of grey or black or white, or colours. Also known as raster, common extensions are bmp, jpg, png, tif --- imagine a sheet of graph paper with squares filled in or left blank --- these are used for background images as templates, and potentially as texture or other inputs for CAM
  • vector --- these are files which are made up of mathematically described dots, lines, arcs, and/or curves, making up either open or closed paths. Note that it is possible for most vector file formats to also include pixel elements, or even to be nothing more than a wrapper around a pixel file, common extensions are .ai, .eps, .pdf, .svg

Note that it is possible for some file formats to include both elements, SVG and PDF are both notable for allowing this. ​

What file formats does Carbide Create save?

Carbide Create outputs two different file formats in the normal course of its usage:

  • .c2d --- this is its native format, such files are warned of not being saved on closing. A .c2d file once saved may be re-opened and modified and adjusted or completed
  • .nc --- these are exported, not saved, and are G-Code which are simply machine instructions on how to move the machine and are an output, not a reusable file format. A .nc file may be opened in Carbide Motion Machine Control Software to the machine, but Carbide Create cannot re-open it (in theory such a file can be processed using 3rd party tools such as G-Code Ripper by Scorchworks or pstoedit and converted into an editable format).

Recent versions have gained the ability to export the geometry as an SVG, or a depth map of the Pro mode's 3D model as a PNG.

What file formats can I use with the Nomad883/Shapeoko 3?

The Nomad883 and Shapeoko 3 use Grbl, an opensource motion control program which implements the G-Code standard (or at least, a subset of it, providing the entire standard is neither feasible nor desirable) for the Carbide Motion micro-controller.

This means that one can use as a design source, any file which can be imported into a CAM (Computer Aided Manufacturing) program which will export to G-Code.

Both the Nomad and Carbide 3D's SO3 support Carbide Create, an all-in-one drawing program which does design, and CAM, in concert with Carbide Motion: http://carbide3d.com/carbidecreate/download/ (CC will import .dxf and .svg files, and will also V-carve or engrave drawings and/or text, and will allow one to place pixel images on a background layer to trace or re-draw them)

  • DXF (Drawing Interchange Format, or Drawing Exchange Format) is a CAD data file format developed by Autodesk for exchanging drawings. Most CAD programs are able to export to a .dxf, e.g., AutoCAD, Cadintosh, LibreCAD, DraftSight, PowerCADD, FreeCAD (n.b., MeshCAM supports the R12 standard) as well as some vector drawing programs.
  • SVG (Scalable Vector Graphics) --- when opened, one will be able to specify the thickness to which filled elements will be set

Carbide Create can also import pixel images to place on the background for re-drawing, and has an option Pro, 3D modeling mode which allows the import of texture files so that they may be cut --- this texture feature may be used to cut greyscale pixel images as depth maps mapping grey values to heights/depths.

For the Nomad883, a MeshCAM license is included with the purchase of a machine, so one may use the additional file formats which it supports:

  • STL (STereoLithography) is a 3D file format which defines 3D shapes as a mesh of triangles. Most 3D CAD programs will export to .stl, e.g., Rhino, Solidworks, Autodesk Inventor, Viacad, Blender, Sketchup, Tinkercad, AutoCAD, Alibre, ZBrush and OpenSCAD (licensing discussion)
  • Image files (JPG, BMP, or PNG) --- MeshCAM also supports importing a pixel image and converting it into a 3D file for cutting. Carbide Create allows one to place a pixel image on a background layer so as to use it as a reference and in "Pro" mode can import pixel images to use as 3D textures.

One may if desired, purchase a license and use MeshCAM with a Shapeoko 3. http://www.grzsoftware.com/

It is also possible to convert vector drawings, (EPS, SVG, some PDF files, i.e., those done in a Bézier curve drawing program/as vectors) into files which the machine can cut using a CAM program which accepts such files. One free and opensource toolchain for this is Inkscape and MakerCAM:

  • Inkscape is an opensource vector drawing program (available for Windows, Mac OS X and Linux) which uses SVG (Scalable Vector Graphics) as its native file format. It may be downloaded from: https://inkscape.org/. Commercial programs able to create .svg files include Adobe Illustrator (Windows and Mac OS X) and Affinity Designer (Mac OS X)
  • MakerCAM is an opensource CAM program which will import an appropriate SVG and allow one to assign operations such as drill, follow path, pocket and profile so as to cut the design out as one wishes. A Flash file, it is available on-line from: http://www.makercam.com/

A further option is to simply directly engrave text, Carbide Create has added support for this. Some tools allow direct use of a pixel image, an opensource tool for this is F-Engrave.

Once CAM is complete, the machine instructions will be saved as G-Code, usually with an appropriate file extension, typically .gc, .gcode, .ngc, or .tap.

Further information is available at Workflow.

Commercial file formats

  • .crv --- Vectric's proprietary format for Vcarve
  • .f3d --- Autodesk Fusion 360 project archive
  • .mcf --- MeshCAM native file format
  • .tps --- MeshCAM toolpath settings