The CNC Router
In as many sectors as of the mostly metal- or wood-processing industry, the so-called CNC milling is very popular. But what is a CNC Router machine? What materials can be processed with a CNC Router machine? And above all: How does such a machine work? In the following all these questions are answered.
What is a CNC Router ?
To understand what exactly a CNC milling machine is, it would be important to know what the word CNC means. CNC is an abbreviation of the English description “computerized numerical control”, and referres to an electronic method for controlling machine tools. Consequently, a CNC milling machine is nothing more than a machine tool, which is numerically driven with computer assistance to process a variety of materials, such as Metals, wood, granite and much more.
It is able to produce very precise and complex shapes and contours by machining materials with a tool. A CNC milling machine achieves these results via at least three axes, called X, Y and Z. The X-axis is horizontal, the Y axis vertical, and the Z-axis refers vertical to the other two axes. These, seen figuratively, result in a so-called portal, which is why CNC milling machines with such a portal formation (X axis designed as a bridge)are often called portal milling machines. In addition, some milling machines have an A, B and C axis representing a rotation around the main axes X, Y and Z.
How does a CNC Router machine work?
As already mentioned, CNC Router machines are controlled by a computer. All necessary data, in form of so-called G-codes, are assembled into a CNC program. The G-codes consist of a “G” followed by a number and type of milling work instruction. Since these codes are standardized, they may be based on a CNC control software used in almost all CNC milling machines. When all data has been inserted and the CNC program is ready to play, the milling machine can begin its work. Manufacturers have added their own codes to the ISO G-codes. Therefore, various post-processors exist to generate ultimately “matching” programs from CAM programs for all different machines.
By a rotation of the respective tool, or a spindle adapted to the material, opposite the clamped workpiece, a cutting movement is produced, which is necessary for the desired chipping. This has already been determined in the records based on the G-codes. The movement of the milling tool around the workpiece, ensures the predetermined shape. This can be done, depending on the design of the router, by displacement of the workpiece on a movable machine table. By using all axes, almost all workpiece geometries are possible e.g .:
- 3D models for architecture and model construction
- 3D freeform surfaces
- Rotosymmetrical workpieces
- Lettering in 2D or 3D
- Engravings in 2D and 3D
- and much more
Have a look at the versatile application possibilities of a milling machine!
What materials can a CNC Router machine process?
A milling machine has the ability to process many different materials.
Listed here are just a few materials that can be machined on a CNC milling machine 2D or 3D:
- Metals / Non-ferrous metals
- Noble metals such as silver, gold
- Steel and cast steel
- acrylic glass
- Granite and marble
Is important to note that some materials, such as e.g. Aluminum, require cooling during the actual milling operation. The heat generation means that chips can clogg or glue the flutes of the milling machine and the milling tool breaks. Suitable coolants and lubricants can be found in the range of most CNC milling machine manufacturers.
What criteria are decisive when buying a CNC Router ?
If you have decided to buy a CNC mill to facilitate some work or to make special work possible, immediately one question comes to mind: “What do I have to consider when buying a CNC machine?”
- The size
Before I search for a suitable manufacturer, I should have a good idea of in which size I want to edit the desired material. Because the maximum travel, dictates the maximum size of my workpiece. Do I perhaps prefer to process larger workpieces? Then I should observe the maximum travel of the selected CNC machine.
- The motor and its performance
Furthermore is crucial which materials I would like to process because this depends on the required performance of the milling spindle. Soft materials such as wood consumes significantly less drive power than hard metals such as steel or cast steel. Here a competent milling machine manufacturers will be happy to advise you.
- Hardness and toughness of the material
Also with respect to the torsional rigidity of the machine, the material to be processed is crucial. Soft materials will demand the milling machine other than hard materials, such as aluminum and steel. The harder a material is, the stiffer the CNC mill should be built. Only in this way a high accuracy in hard materials, especially metals, are guaranteed.
A CNC milling machine should be as well adapted to the material to be machined as possible . Someone who workes mainly wood should get a one-on tailored CNC machine. The more accurately the CNC milling machine fits to the demands of the material, the more accurate the milling results.
With these 4 questions I quickly find out what CNC milling machine is suitable for my needs:
- What size are my workpieces to be processed?
- What engine power do I need for my hard / soft material?
- How hard are the materials to be processed with regard to the required torsional stiffness of the CNC milling machine?
- How exactly is the selected CNC milling machine adapted to my desired materials / workpieces?