Vertical Machining & CNC VMC: A Comprehensive Introduction

The knife is attached and rotated in a housing called a "spindle". Due to the sharpness of the tool and the strength of the table pushing the material into the knife, the material is deformed and is properly cut or shaved. The force axis can be directed up / down (called the Z axis) left / right (called the X axis) or from front to back (called the Y axis).

VMCs can be equipped with many adjustments. For example, there are many approach angles, as well as rotary and other positioning devices on the work table. Later versions of the VMC project added power and hydraulic feeding devices to make the system more automated, and finally computerized controls were added to allow greater automation of work, repeatability, tool selection / change and contour control. These new CNC machines took the "milling machine" to a new level of efficiency and therefore the term VMC (Vertical Machining Center) was born.

 

CNC VMC: Fundamentals of the process

VMCs are primarily used (though not exclusively) as metal cutting machines that remove steel, aluminum or other hard materials - thus forming a raw block of material into a precisely formed or "machined" surface.

VMC can be used not only for cutting, but also for drilling, carving, engraving, threading, countersinking, chamfering and many other applications. Due to their versatility and relatively low cost, these are extremely popular machines that can be found in workshops around the world. In fact, there is a good chance that the machine works just a few kilometers from where you are now.

All VMC consoles use common components, which are as follows:

Rotary spindle - A spindle that is perpendicular to the work surface or table can accommodate various cutting tools (or mills, as they are sometimes called). The spindle cartridge is mounted in a housing that moved up and down - this direction of movement is called the Z axis.

Table - The table is a platform on which workpieces can be mounted - directly or by means of various devices, such as milled aluminum plates or hard clamping vices. The table has left and right movement, which we call the X axis, and from front to back, which is called the Y axis. These two motion axes, in conjunction with the Z axis, allow virtually unlimited contouring on the planes of motion.

 

Additional Common Elements

Wide range of vertical machining center

Tool changer - The tool changer significantly increases the VMC performance by enabling automatic, computer-controlled tool selection for a variety of tasks, from roughing to fine hole drilling.

Cooling system - To maintain the cooling and lubrication of parts and cutters, most VMC machines use some type of recirculating cooling system; which is usually a mixture of soluble oil and water, but can also be a diverse liquid.

Chip / screw conveyor - To remove chips from the work area, various chip conveyors and chip screws can be used to increase efficiency and reduce downtime caused by manual removal of waste chips.

Full covers / housings - these can be added to reduce spattering / spattering caused by milling operations and to protect operators and the environment from machining.

Rotary tables - adding additional axes to the machine can significantly increase its efficiency by transforming a simple three-axis machine into a four or even five-axis system capable of machining complex elements with different surfaces (such as turbine blades).

Quick charging of chargers - Another great addition significantly increasing productivity is the use of shuttle tables or other automatic parts loading systems. This can reduce downtime and significantly extend the spindle ON time in most VMC systems.

Typical VMC applications include: Machining parts for assembly, castings, automotive, mold / die production, and many other metal cutting tasks.

 

Vertical machining centers with advanced functions and functions are gaining popularity as more productive members of the arsenal of CNC machines in workshops. Today's VMCs challenge the view that they must be sent to some rarely visited dark corners of the store or limited to post-treatment. VMCs have traditionally been cheaper compared to horizontal machining centers, but without the possibility of production.

To some extent, the latest additions to advanced technology have enabled VMC to close the productivity gap and provide competitive advantage in fast and precise applications as diverse as the aerospace, medical, energy and similarly demanding industries. The functionality of VMC has been significantly increased by adding table and spigot table configuration for the fourth and fifth axis, many pallet changers, more tools and high speed spindles. VMCs are able to process the most complex components such as jet rotor blades, turbine blades for power generation, large aircraft components and precision molds and dies.

The advanced features of some machines allow you to ensure the shortest possible machining cycles, especially in exact increment programs for simultaneous five-axis operations and free die machining, says the company. These features include high gain feed control, fast rotary axis speeds, variable acceleration control and intelligent pocket milling. Special gear design software and metrology units can be integrated into the closed-loop machining process.

VMC advanced axis offsets accommodate parts up to 19.88 inches (505 mm) in diameter and 12 inches (305 mm) high. The fast rotation speeds for these three linear axes are 1181 ipm (30 m / min). Some machines are equipped with a high-performance CAT-40 spindle with a speed of 12,000 rpm for machining of all common materials, including steel, aluminum and cast iron. Optional spindle speeds of 15,000 rpm and 20,000 rpm are available.

The ATC 60 tool helps reduce setup time, allows unnecessary tooling and provides an increased number of unmanned, uninterrupted operations. This process gives workshops a highly precise and cost-effective option for machining small and medium gear lots with standard tools.

See Product: Auto Tool Changer