The 2D CNC process from start to end
This is a description of the complete process of taking a graphic shape file and cutting a 2D object on a CNC machine. The first step is to find an graphic image that you want to cut. Sounds easy, just search the web for an image you like. If you have only a 2 axis CNC machine (like my hotwire cutter) then some graphics are much better then others, because they do not contain enclosed areas. If you have a 3 axis machine, then this does not matter, as the CNC machine can lift the cutting head and move it to any isolated areas. The picture below illustrates an image with lots of enclosed spaces and what would happen when you fill it in to make an outline silouette. A 3 axis machine would work fine on the original picture. So a 2 axis machine is going to limit you to doing pure silouettes.
If the image has only a few enclosed areas, then small cuts can be made in the image to allow a 2 axis machine to get to the enclosed areas in order to cut them out. It is a little more time consuming, as you have to find a good place to make the cuts, a place that is both visually pleasing and will maintain the overall shape integrity. Take the hiker image below. I would make three changes to the original in order to cut it on a 2 axis CNC machine. First, I two cuts in the image to allow the enclosed spaces to be cut out. Second the small rock on the right side is attached to the larger rock through a very small piece of material. I made the attachment to the larger rock a little thicker than the original image. All CNC machines have an absolute accuracy to their cuts and on a hotwire cutter making anything too small chances that it will cut (melted) completely through.
Now the image file needs to be turned into a computer aided design (CAD) file. Simply put an outline vector shape needs to be created around the existing image silouette. The vector shape file also needs to be formatted as a DXF to allow for the easy conversion to gcode.
1) If you can afford the software, Adobe Illustrator has a built in tracing feature that can trace images automatically and create a vector shape files. The Illustrator shape file can be read into a 3D program, such as Cinema 4D, which can write out DXF files. The DXF file can be read into the free DAK ACE converter to create Gcode for Mach3, a CNC machine controller program.
2) An alternative is to import the image file directly into a 3D program, in this case Cinema 4D, and set the image as a background. Then using the spline drawing tools in Cinema 4D manually trace around the image, exporting to a DXF file when finished. Other commercial 3D programs probably have a similar feature allowing DXF file creation.
3) Inkscape. Is an open source program like Adobe Illustrator. It can trace images automatically like Illustrator and create vector shapes. I am still experimenting with this program. Hopefully it will be the completely "free" way to create 2D Gcode.
In summary:
Search for an image on the web.
Download the image.
Edit the image for CNC use. Photofiltre is an excellent free image editing tool.
Create a DXF vector. Commercial 3D programs $, or hopefully Inkspace.
Create Gcode. The free DAK ACE converter.
Run CNC machine. MACH3 controller program $, MACH3 will do 500 lines of Gcode in its free demo mode. Free alternatives would be CNCPro or the shareware TurboCNC.
Also check out this website at Probotix for more CNC software options
1) If you can afford the software, Adobe Illustrator has a built in tracing feature that can trace images automatically and create a vector shape files. The Illustrator shape file can be read into a 3D program, such as Cinema 4D, which can write out DXF files. The DXF file can be read into the free DAK ACE converter to create Gcode for Mach3, a CNC machine controller program.
2) An alternative is to import the image file directly into a 3D program, in this case Cinema 4D, and set the image as a background. Then using the spline drawing tools in Cinema 4D manually trace around the image, exporting to a DXF file when finished. Other commercial 3D programs probably have a similar feature allowing DXF file creation.
3) Inkscape. Is an open source program like Adobe Illustrator. It can trace images automatically like Illustrator and create vector shapes. I am still experimenting with this program. Hopefully it will be the completely "free" way to create 2D Gcode.
In summary:
Search for an image on the web.
Download the image.
Edit the image for CNC use. Photofiltre is an excellent free image editing tool.
Create a DXF vector. Commercial 3D programs $, or hopefully Inkspace.
Create Gcode. The free DAK ACE converter.
Run CNC machine. MACH3 controller program $, MACH3 will do 500 lines of Gcode in its free demo mode. Free alternatives would be CNCPro or the shareware TurboCNC.
Also check out this website at Probotix for more CNC software options