CNC routers enhance one’s DIY capabilities significantly. However, the difficult part comes when you need to program the device to suit your cutting or machining needs. If you have worked with a manual milling machine, you should not find using the CNC router a challenge.
It uses a similar concept. CNC routers use CAD and CAM software, which you need to learn how to program to execute your needs. Once you have set up the equipment, proceed to:
Design the Part
The first step to cutting the material is to draw or create the three-dimensional object of the item you want to cut. Most people are used to 2D dimensional cut-outs, but in this case, we use a 3D drawing as objects take spaces in three directions (left to right, down, and front and back).
Alternatively, use a CAD program to generate the drawings. Software such as Inkscape and Draftsight come in handy though they are free AutoCAD software. Inkscape is suitable for generating artistic pieces, while Draftsight is ideal for creating dimensionally-driven images.
For 3D designs, Sketchup is the standard software, but you can also use Solidworks and Pro/E. Regardless of the design software, you need to allocate a decent amount of time figuring out how to generate the parts.
Note, designs for CNC wood routers are restricted to the capabilities of the machine. For example, if the device is designed to make cylindrical designs, then the machining process is limited as the tool is likely to create curved corner sections.
Also, the material getting machined, the machine’s tooling design, and work holding capabilities restrict the design possibilities with regard to thickness, size, and complexity of internal cavities.
Generating the G-Code
The formatted CAD design file then runs through a computer-aided manufacturing software to extract the acquired geometry and produce the digital programming code which controls the machine.
CNC routers use different programming languages, but the most common is the G-code and M-code. G-Code is a programming language used to control how, when, and where CNC tools move, i.e, when to turn the machine on or off, what path to follow, how fast to go to a specific location, on the workpiece. The M-code, on the other hand, controls additional functions of the machine. Such functions include automating the replacement or removal of the machine cover at the beginning and the end of the process
Generally, you don’t need to learn the entire G-code to program the CNC router. Instead, you can learn a few G-code commands and write your programs. Alternatively, purchase software that can write the codes.
Since such software is expensive, most professionals prefer using a CAM program to produce the G-code and translate the CAD model into the required format. Here are some CAM software plans you should consider:
- G-code tools for Inkscape: The software is available for free and ideal for art-generated on Inkscape. The documentation takes a little time to learn
- MeshCAM: This kind is suitable for 3D users. It boasts an attractive user interface and offers some pretty handy features.
- CAMBam: It is reasonably priced ($149) and has a free trial period professionals can use to try out before subscribing to a package
- ESTLCam: If looking for affordable software, the ESTLCam is an excellent buy. It is suitable for creating 2D designs
- Custom CAM routine: This software is ideal for professionals already versed in a programming language. It helps users write their Gcode generating script
Apart from interpreting the G-Code language, the software also helps you set up the feeds, depth of cut, and other parameters. It would help if you also considered the speed the CNC router can handle and what to do to avoid crashing the equipment.
Learning CNC Language
Whether you want to create an arc, a straight line, route a pocket, or drill a hole, you need to generate the right command. Some CNC phrases you can master include:
- Go: It is to move at full speed to a designated point
- G1: Instructs the machine to cut a straight line
- G2: A command to cut an arc in a clockwise direction
- G3: A command to cut an arc in an anti-clockwise direction
- G4o: The machine should cut the material in the middle
- G41: The machine cuts the material to the left of the line through the radius
- G42: CNC router should cut the material to the right of the line via the radius
- G20/G21: The commands are used to give coordinates in inches or millimeters
Controlling the Router
Once the CAM program generates the codes, the machine software will start creating the desired design on the work material. You may use software like the Mach3 if working on a DIY project.
It takes time to get used to it, but it has some pretty impressive results. However, you will realize that you need a parallel port for the device to work correctly.
Another option is the LinuxCNC. It delivers excellent results; the only challenge comes when using the new Operating System together with a new router. You may need a little time to get used to it.
Once you learn how to write G0-G3 and G40-G42 commands, then you can write simple programs. Also, practice programming in millimeters, e.g., by writing G21. When you have learned how to use these commands, then you know enough G Code to create various CNC programs.
Cutting the Wood
The final step involves using the router to cut the material. You get to watch all the work coming to life, the blank piece of wood transforming into the desired object. Before running the CNC program, prepare the machine for the operation.
You need to fix the workpiece onto the machine, machine vise, spindle, or similar work holding device and attach the required tooling (end mill, drill bit) to the machine component.
Then initiate the program for the machine to start executing the code. The program provides instructions as to how the device will move and what actions it will take. Be sure to remain close to ensure the machine does not encounter problems.