CNC machining

CNC stands for Computer Numerical Control. It's a manufacturing process that uses computerized controls to operate machine tools.   Working Principle   - The CNC system reads a set of coded instructions (the G - code and M - code). These instructions tell the machine tools, like milling machines, lathes, or routers, how to move and operate. For example, in CNC milling, the machine precisely cuts away material from a workpiece to create a specific shape according to the programmed instructions.   Advantages   - High Precision: It can achieve very accurate and repeatable results. For example, in the production of aerospace components, CNC machining can ensure that parts are made with extremely tight tolerances. - Increased Productivity: Once programmed, the CNC machine can work continuously and often at a faster speed than manual operation. It also allows for lights - out manufacturing, where the machine can operate without human supervision for extended periods.   Applications   - Automotive Industry: CNC machines are used to manufacture engine parts, transmission components, and body parts. - Aerospace: To produce turbine blades, structural components of aircraft, and other precision parts. - Furniture Making: For cutting and shaping wood or other materials to create furniture components with complex designs.    

  Tool access is one of the main design limitations in CNC machining. To reach all surfaces of the model, the workpiece has to be rotated multiple times.  Whenever the workpiece is rotated, the machine has to be recalibrated and a new coordinate system has to be defined. While designing, it is important to consider machine setups for two reasons: The total number of machine setups affects the cost. Rotating and realigning the part requires manual work and increases total machining time. This is often acceptable if the part needs to be rotated up to three or four times, but anything above this limit is excessive. To achieve maximum relative positional accuracy, two features must be machined in the same setup. This is because the new calibration step introduces a small (but non-negligible) error. What is 5-axis CNC machining? A 5-axis CNC machine moves cutting tools or parts along five axes at the same time.  Multi-axis CNC machining can manufacture parts with complex geometries, as they offer two additional rotational axes. These machines eliminate the need for multiple machine setups. What are the advantages and limitations of 5-axis CNC machining? Five-axis CNC machining allows the tool to remain constantly tangential to the cutting surface. The tool paths can be more intricate and efficient, resulting in parts with better surface finish and lower machining times. That said, 5-axis CNC has its limitations. Basic tool geometry and tool access limitations still apply (for example, parts with internal geometries cannot be machined). Moreover, the cost of using such systems is higher. CNC machining undercuts Undercuts are features that cannot be machined using standard cutting tools, as some of their surfaces are not accessible directly from above. There are two main types of undercuts: T-slots and dovetails. Undercuts can be one-sided or double-sided and are machined using special tools. T-slot cutting tools are made of a horizontal cutting blade attached to a vertical shaft. The width of an undercut can vary between 3mm and 40mm. We recommend using standard sizes for the width (i.e. whole millimeter increments or standard inch fractions), as it is more likely that an appropriate tool is already available.  For dovetail cutting tools, the angle is the defining feature size. Both 45- and 60-degree dovetail tools are considered standard. Tools with an angle of 5-, 10- and up to 120-degree (at 10 degree increments) also exist but are less commonly used.