VMC 855 Vertical Machining Center: Precision and Power in Manufacturing

In the dynamic realm of modern manufacturing, the VMC 855 Vertical Machining Center has firmly established itself as a paragon of versatility and high - precision machining. This advanced machine tool is engineered to meet the exacting demands of a wide array of industries, from aerospace and automotive to electronics and mold - making.

Structural Design and Build

Robust Base and Bed

The VMC 855 is built upon a substantial base and bed, typically crafted from high - grade Meehanite cast iron. This material choice is strategic, as Meehanite offers exceptional rigidity, excellent damping properties, and remarkable dimensional stability over time. The base is designed with a broad footprint and an intricately ribbed internal structure. This not only provides a rock - solid foundation for the entire machine but also effectively dissipates vibrations generated during high - speed machining operations. The bed features precision - ground guideways, which are critical for ensuring the smooth and accurate movement of the table and other components. Some models may employ linear guideways, such as those from renowned manufacturers like Hiwin or PMI. These linear guideways are lauded for their low - friction characteristics, high load - carrying capacity, and outstanding positioning accuracy. They enable rapid and precise movement of the table, which is essential for efficient machining. In addition, the guideways are often hardened and ground to enhance their durability, ensuring long - term reliable performance even under heavy usage.

Sturdy Column and Spindle Assembly

The column of the VMC 855 is a key structural component. It is designed to support the spindle head and guarantee its precise vertical movement. Constructed with a large cross - section and a rigid build, the column can withstand the substantial forces exerted during machining. The spindle, which lies at the heart of the machining process, is housed within the spindle head. The VMC 855 offers a range of spindle options to suit different applications. Standard models often come equipped with a belt - driven spindle, which strikes a balance between cost - effectiveness and performance. However, for applications demanding higher speeds and greater precision, direct - driven spindles are available as an option. These direct - driven spindles can achieve impressively high rotational speeds, often ranging from 6000 to 12000 RPM or even higher in some advanced configurations. They also offer reduced vibration and enhanced torque transmission, resulting in superior surface finishes and more accurate machining. The spindle is supported by high - precision bearings, carefully selected to handle the high speeds and loads associated with machining. These bearings ensure smooth rotation and minimal run - out, which is crucial for achieving the tight tolerances required in modern manufacturing.

Versatile Table and Workholding

The table of the VMC 855 is designed to securely hold and accurately position the workpiece during machining. It typically has a rectangular shape and is equipped with a T - slot pattern. This T - slot pattern allows for the easy installation of various workholding devices, such as vises, clamps, and fixtures. The table size of the VMC 855 is commonly around 1000 x 550 mm, providing a generous working area that can accommodate a diverse range of part sizes. The table is capable of moving in the X and Y directions, which are perpendicular to each other. Its movement is achieved through the use of high - quality ball screws, which are driven by servo motors. These ball screws convert the rotational motion of the motors into smooth and precise linear motion, enabling the table to move with exceptional accuracy. The table also has a maximum load - carrying capacity, which is an important consideration when machining large or heavy workpieces. In the case of the VMC 855, the table can usually support loads of up to 500 kg, depending on the specific model, ensuring it can handle a wide variety of machining tasks.

Machining Capabilities

Milling Operations

Face Milling

Face milling is one of the fundamental operations carried out on the VMC 855. In this process, a face milling cutter, featuring multiple cutting teeth, is mounted on the spindle. As the spindle rotates the cutter at high speeds, the table moves the workpiece in a precisely controlled manner. This allows the cutter to remove material from the surface of the workpiece, resulting in a flat and smooth finish. Face milling is extensively used in applications where a large flat surface needs to be machined, such as in the production of machine bases, plates, and other components with planar surfaces. The VMC 855's ability to precisely control the feed rate, spindle speed, and depth of cut ensures that the face - milled surfaces meet the tightest tolerances. For example, in the manufacturing of aerospace components, the flat surfaces produced by face milling on the VMC 855 must have extremely low surface roughness and tight dimensional accuracy to ensure proper fit and function.

Peripheral Milling

Peripheral milling, also known as slab milling, involves using a milling cutter with teeth on its periphery. This type of milling is used to create grooves, slots, and other features on the sides of the workpiece. The VMC 855 can perform peripheral milling operations with great accuracy. When machining a keyway in a shaft, the operator programs the VMC 855 to move the table in a specific path while the spindle rotates the peripheral milling cutter. The machine's high - precision positioning capabilities ensure that the keyway is machined to the exact dimensions required. This is crucial in industries such as automotive, where precise keyways are necessary for the proper functioning of components like gears and shafts.

Contour Milling

Contour milling is a more complex operation that enables the creation of intricate shapes and profiles. The VMC 855 utilizes its multi - axis control (usually three - axis, but some models may offer additional axes for more complex machining) to move the cutting tool along a predefined path, following the contour of the part design. This is particularly valuable in the manufacturing of molds, dies, and parts with complex geometries. By programming the appropriate tool paths, the VMC 855 can produce parts with smooth curves and sharp corners, meeting the high - quality standards demanded by industries such as aerospace and medical device manufacturing. For instance, in the production of medical implant molds, the VMC 855 can precisely machine the complex contours required to create molds that will produce implants with the correct shape and surface finish for optimal patient use.

Drilling and Boring

Drilling

The VMC 855 is well - equipped to handle a wide variety of drilling operations. Drill bits of various sizes can be mounted in the spindle or in the tool magazine for automatic tool changes. When drilling, the spindle rotates the drill bit at a high speed while the table moves the workpiece to the desired location. The machine's control system precisely regulates the feed rate of the drill bit into the workpiece, ensuring that holes are drilled straight and to the correct depth. Drilling operations on the VMC 855 are used in numerous applications, from creating holes for fasteners in mechanical assemblies to producing holes for fluid passages in hydraulic components. In the automotive industry, for example, the VMC 855 may be used to drill holes in engine blocks for the installation of various components.

Boring

Boring is another important operation that the VMC 855 can perform. Boring is used to enlarge an existing hole or to create a more accurate and smooth - walled hole. A boring bar, with a cutting tool attached to its end, is mounted in the spindle. The operator programs the VMC 855 to move the boring bar in a controlled manner, adjusting the diameter of the hole as needed. This operation is crucial in applications where precise internal diameters are required, such as in the manufacturing of engine cylinders, bearings, and other components where a tight fit is essential. In the aerospace industry, the VMC 855 may be used to bore the internal diameters of turbine engine components to extremely tight tolerances to ensure efficient engine performance.

Tapping

Tapping is the process of creating internal threads in a hole. The VMC 855 can be programmed to perform tapping operations with great accuracy. A tap, which is a specialized cutting tool with threads, is mounted in the spindle. The machine's control system coordinates the rotation of the spindle and the feed of the tap into the hole to create the internal threads. Tapping on the VMC 855 is used in the production of parts that require threaded connections, such as nuts, bolts, and components in mechanical assemblies where threaded holes are needed for fastening. In the electronics industry, for example, the VMC 855 may be used to create threaded holes in the casings of electronic devices for the installation of screws that hold the device together.

Technical Specifications

Axis Travel

The VMC 855 typically offers an X - axis travel of around 850 mm, a Y - axis travel of 550 mm, and a Z - axis travel of 600 mm. These travel distances provide a spacious working envelope, allowing for the machining of a wide range of part sizes. The ability to move the cutting tool and the workpiece over these distances enables the creation of complex parts with multiple features. For example, in the machining of large mold components, the generous axis travels of the VMC 855 allow for the complete machining of the mold cavity and core without the need for multiple setups.

Spindle Speed and Power

The spindle speed of the VMC 855 can vary depending on the model and spindle type. Standard spindle speeds usually range from 40 to 8000 RPM, while high - speed spindles can reach up to 12000 RPM. The spindle power is generally in the range of 7.5 - 11 kW, which provides sufficient power to drive the cutting tool through various materials, including metals, plastics, and composites. The combination of high spindle speed and power enables efficient material removal and high - quality machining. For instance, when machining aluminum alloys, the high spindle speed can be utilized to increase the material removal rate, while the sufficient power ensures that the cutting tool can handle the cutting forces without overheating or breaking.

Feed Rates

The VMC 855 has both rapid feed rates and cutting feed rates. The rapid feed rates, which are used to quickly move the axes to the starting position for machining, can be quite high. The X and Y axes may have rapid feed rates of up to 36 m/min, while the Z - axis may have a rapid feed rate of 30 m/min. The cutting feed rates, which are used during the actual machining process, can be adjusted according to the material being machined, the type of cutting tool, and the desired surface finish. The cutting feed rates typically range from 1 to 10000 mm/min, allowing for precise control over the machining process. For delicate machining operations, such as finishing a surface to a high - quality finish, a lower cutting feed rate can be selected, while for roughing operations, a higher cutting feed rate can be used to remove material more quickly.

Tool Magazine Capacity

The VMC 855 is equipped with a tool magazine to enable automatic tool changes. The tool magazine capacity can vary, but common options include 24 - tool positions. This allows for the storage and quick access to multiple cutting tools, reducing the time required for tool changes during the machining process. The tool magazine can be of different types, such as a carousel - type or a disc - type. A carousel - type tool magazine, for example, offers a simple and reliable design, while a disc - type tool magazine may provide faster tool - change times. The tool change time is relatively short, typically within 1 - 3 seconds, further enhancing the productivity of the machine.

Control System and Operation

The VMC 855 is operated using an advanced computer numerical control (CNC) system. Popular CNC systems for the VMC 855 include those from well - known manufacturers like Siemens, Fanuc, Mitsubishi, and also domestic systems such as KND and GSK. These systems allow operators to program the machining operations with a high degree of precision. The CNC programming language, often based on ISO standards, is used to input instructions for the movement of the axes, spindle speed, feed rate, and tool changes. The control system features a user - friendly interface, which may include a touch - screen display or a combination of buttons and a display screen. This interface allows operators to easily enter and edit programs, as well as monitor the machining process in real - time. The CNC system also has the ability to store multiple machining programs, making it convenient for batch production or for quickly switching between different part - machining jobs. Additionally, the VMC 855 may be equipped with a communication interface, such as RS232, USB, or Ethernet, which allows for the transfer of programs from an external device, such as a computer. Some advanced models may even offer features like remote monitoring and diagnostic capabilities, enabling technicians to troubleshoot issues without being physically present at the machine.

Applications

Mold and Die Making

In the mold and die making industry, the VMC 855 is widely used. Molds and dies often have complex geometries and require high - precision machining. The VMC 855's ability to perform contour milling, drilling, and boring operations with tight tolerances makes it an ideal choice for creating molds for plastic injection molding, die - casting, and forging processes. When manufacturing a mold for a plastic automotive part, the VMC 855 can be used to machine the intricate cavities and cores with the required surface finish and dimensional accuracy. The high - speed spindles and precise axis control of the VMC 855 enable the efficient production of molds with fine details, reducing the need for extensive manual finishing work.

Aerospace Industry

The aerospace industry demands the highest levels of precision and quality in its components. The VMC 855 can be used to machine parts for aircraft engines, such as turbine blades, compressor disks, and structural components. These parts need to be machined with extreme accuracy to ensure the safety and efficiency of the aircraft. The VMC 855's high - speed spindles, precise axis control, and ability to handle tough materials like titanium and nickel - based alloys make it a valuable asset in aerospace manufacturing. For example, in the production of turbine blades, the VMC 855 can precisely machine the complex airfoil shapes and cooling holes, ensuring optimal engine performance.

Automotive Industry

In the automotive industry, the VMC 855 is used for machining a variety of components. It can be used to produce engine parts such as cylinder heads, crankshafts, and camshafts. These parts require high precision to ensure the smooth operation of the engine. The VMC 855 can also be used to machine transmission components, such as gears and shafts, as well as parts for the suspension system. The ability to produce parts with tight tolerances and in a repeatable manner makes the VMC 855 suitable for the high - volume production requirements of the automotive industry. The fast tool - change times and efficient machining capabilities of the VMC 855 help to increase production throughput and reduce manufacturing costs.

General Machining and Prototyping

For general machining workshops and in the prototyping phase of product development, the VMC 855 is a versatile tool. It can be used to produce custom - made parts, repair damaged components, or create prototypes for new product designs. The manual override capabilities of the VMC 855, combined with its CNC precision, make it suitable for small - batch production and for making on - the - fly adjustments during the machining process. This flexibility is highly valued in industries where quick turn - around times and the ability to adapt to changing requirements are important. In a small - scale manufacturing shop, the VMC 855 can be used to produce one - off or low - volume parts for various applications, from hobbyist projects to small - business products.

In conclusion, the VMC 855 Vertical Machining Center is a high - performance machine tool that combines precision, versatility, and efficiency. Its robust construction, advanced machining capabilities, and user - friendly control system make it a top choice for manufacturers across a wide range of industries. Whether it's for high - precision aerospace component production, large - scale automotive manufacturing, or small - scale custom work, the VMC 855 has the potential to meet and exceed the demands of modern manufacturing, driving innovation and productivity in the manufacturing sector.