The basic format of CNC machining comes in a 3-axis design. This handles vertical, horizontal and depth positions. Various formulas of the three in different amounts then produce different positions which, when tooling is guided on the same, creates specific shapes. Then, if one wants particularly high-detailed work, a 5-axis approach adds rotation and tilt for an even greater number of results and output possibilities. However, between those two choices increasing demand for CNC systems and their possibilities, there is another alternative, the 4-axis CNC machine approach. It is not the most widely known choice, but it can be ideal for certain part production needs, especially when the intricacy of a higher level is not needed, but the basic 3-axis isn’t detailed enough.
4-axis CNC machining, at least by design approach, existed before other more practical systems came into place. However, to start producing real applications, limiting things to a 3-dimensional capability was easier, creating a foundation for enhancements after the fact. The addition of the 4-axis approach essentially adds basic rotation to the target material. This isn’t rocket science; for years many manual artisans have been utilizing spinning tables for their work, making it easier to achieve a specific angle. However, for the CNC machine environment, the target resource was generally fixed, with the tools working around it. By adding rotation, the tools can apply continuous work in a rotational aspect, or they can effect changes at different positions automatically as the item is spun, stopped, spun again, stopped and so on. It all depends on the programming applied to control the tooling. The key result is arcing, the ability to apply a shaping as the part is turned.
In practice, programmers take advantage of the 4-axis option with two methods: continuous or indexing. The indexing is, as described above, a stop-and-go approach. It locks the target material when the rotational axis is locked. Then the item is rotated again to the next position and locked. Each stop is a fixed increment, which then allows for a systematic application of work around the part instead of in just one location. Continuous, on the other hand, has the rotation or 4th axis moving and not stopping. The changes are grinded or beveled off the target part as the part spins, creating an arc application or circular removal of material from the part, either on the outside or internally to create cavities.
Applications vary but the 4th axis CNC machining is definitely useful for gears and circular parts that need to be ideally round but might have different edging and formations for their function. Gears, for example, require various types of divots, teeth, impressions and even waves, depending on how the gear is supposed to drive energy to the part that it is mated to. Fabricating these parts typically involved manual work or stamping, i.e., pressure applied shaping. However, with 4-axis CNC machining gears of different varieties, shapes, movement and drive can be created, not just with very high accuracy but also with efficient mass production as well. That makes the same product generation go much faster, especially when the same gears are needed for the assembly process and other manufacturing deadlines, depending on the parts being available.
Other components, part styles and shapes are far more possible with a 4-axis approach as well. Conic or cylindrical part creation is definitely another practical example, especially where the cylinder or cone is changing diameter from one side to the other. This can apply in engineering fabrications, intricate motoring, and timed sequence assemblies. Again, specialized part creation that mates with other parts is targeted with this tooling capability, and it’s been put to good use in industries where far more challenging shaped parts are needed in different plane types. However, as robotics is coming into vogue, similar parts are needed as well for that environment and its constructs.
Another big advantage of 4-axis CNC machining comes in the form of applied contact, particularly with engraving needs. Since the target material is rotated, the user doesn’t need to focus on shaping or cutting material from a flat perspective. Instead, the target material just rotates, and the engraving is applied on a diameter-measured edge surface. This is particularly useful for labeling, key coding, instructions, part numbering and similar on curved surfaces.