How to select the appropriate CNC internal grinder for your project. CNC (Computer Numerical Control) is a technique for producing products where material is moved and controlled via a machine rather than being manually moved. The most popular form of CNC is the additive method, where a pre-programmed, predefined blank tool path is followed by an automated, free-hand path. This allows for a much greater degree of control during the grinding or drilling operation. In CNC, the operator just lets the machine do the work.
Most CNC machines are designed with two or more grinding stages. The first, called the ‘ado’ stage, grinds the material to a high precision. The second, the ‘carburizing’ stage, which is also known as the ‘knife edge’ stage grinds material to a lower tolerance. Since the second stage is not as precise as the first one, it usually employs a lower tolerance printable product and is mostly used in CNC milling operations.
Grinding of aluminum and stainless steel is more difficult that of steel or brass. Typically, a CNC milling operation includes a number of diamond-tipped grinding stones set inside a resin bed. These diamonds are made of high-precision quartz crystals that lock together at the setting points. CNC internal grinders are particularly useful for applications where a high tolerance of chatter is required, such as precision component and switch board fabrication. Some internal grinders are also capable of processing both aluminum and stainless steel without significant degradation in either material. Some other examples of CNC internal grinders include blade grinders, which are primarily used in hand-engraving applications; and rotary grinders, which are primarily used in grinding solid materials such as granite.
The main advantage of a CNC internal grinder over other types of grinding wheels is that the interior of the rotating mechanism is completely sealed from dust, and heat. In addition, the interior of the wheel provides a very smooth riding surface, due to the absence of a metallic face to collect and redistribute heat. Also, due to the design of the inside of the CNC grinder, all the critical operating parameters are easily adjustable by means of a computer-controlled program. This enables the operator to fine tune each of the individual components for maximum performance.
The major disadvantages of CNC internal grinders are their somewhat steep learning curve. Since the machine operates on a program, the operator must be knowledgeable enough about how to operate the machine in order to successfully perform the necessary grinding tasks. Also, since each individual grinding stone in the CNC machine is precisely ground at the time of operation, there is typically no room left to make minor adjustments during the grinding process. Also, CNC internal grinders are only useful for cutting diamond-free material, because all possible cubic zirconia contaminants must be removed before the machine can be used to grind anything else.
CNC internal grinders are usually used in large-scale industry to provide the precision and accuracy needed in abrasive material grinding and polishing. Typically, CNC internal grinders are used in industries where high-quality parts and materials are a top priority. As with any type of machine, these types of machines are available in various sizes and configurations. However, the best way to choose a CNC internal grinding machine depends upon your specific needs, budget and available space. If you plan on operating your CNC machine in a production environment, then you should opt for a larger CNC machine with higher number of cutting stones and gears. Otherwise, a smaller machine will suffice for most applications.