Machining involves the use of tools to help shape, plane, cut or turn a workpiece in order to prepare the surface for further finishing, or to help complete the part. For instance, machining may help remove burrs of excess metal formed on the exterior of a metal part during the die casting process. This step may also prepare the surface of a part for welding or for eventual assembly operations. A machinist may create holes in workpieces to hold bolts, screws or rivets, for instance.
During previous historical eras, machinists sometimes employed a variety of manual tools. However, the rise of computers has allowed automation to play a more significant role during this manufacturing step. Today, manufacturing firms sometimes use computerized machining tools in conjunction with libraries of software programs to help automate the machining phase.
All “CNC” machines rely on a computer numerical control process to direct the movement of a cutting tool during machining. Typically, a software program will direct the movements of spindles containing cutting tools across a vertical or horizontal grid.
CNC machines vary widely in their use of computerized interface devices. Additionally, different CNC machines may use spindles and cutting tools of variable sizes. Several important types of CNC machines in widespread use today in production facilities include:
A software program directs the movement of an automated rotary cutting tool held perpendicular to a workpiece. Milling may produce a desired surface texture on a machined part during finishing, for instance. These machines often help prepare the surface of a metal part to accept specific coatings, also.
These computer-controlled machines permit the automated turning of a workpiece at desired angles. Typically this action allows portions of the surface of a workpiece to come into contact with one (or more) cutting blades.
A computer-directed machine uses a revolving vertical spindle and cutting tool to mill out the surface of a metal or wooden workpiece. The surface of the tool may create grooves or channels across the surface of a workpiece, for instance.
CNC Plasma Cutters
A computer-controlled plasma arc cutting machine employs a constrained cutting plasma arc to cut through a metal workpiece quickly and easily. The arc, often shielded and constrained by an outer layer of flowing gas, melts the substrate rapidly.
CNC Laser Cutters
A software program directs the movements of a cutting laser channeled through a constricted opening, sometimes in conjunction with a vaporizing gas cutting tool.
5-Axis CNC Machines
A 5-axis CNC machine typically moves a cutting tool across a 3-dimensional range of motion, while also permitting the angling of the cutting tool along two axes.
These machines offer some important advantages. First, they may permit a machinist to generate complex shapes without extensive re-tooling. Second, a more flexible machine may lower the cutting head closer towards the work surface, minimizing the vibration of the tool and permitting rapid cutting.
For example, machinists using these tools may gain the ability to drill precise holes in workpieces quickly and easily. The ability to vary the angle of the holes slightly along a work piece often increases the speed of a subsequent assembly process.
5-Sided (3+2 Machining) vs. Simultaneous 5-Axis
An important distinction exists between 5-sided (or “3+2” machining) and 5-axis machining. During 5-sided cutting, the tool cannot adjust while moving; instead, it remains in a specific position dictated by two rotational axes.
Continuous minute adjustments of the cutting blade by contrast occurs during simultaneous 5-axis machining. These machines enable the blade to always maintain a desired perpendicular angle vis-à-vis the workpiece. This procedure tends to require far more complex software programs as a result, and implementing simultaneous 5-axis machining may challenge the programming departments of some fabrication companies. Nevertheless, it does offer the ability to reproduce very complex parts quickly.
5-Axis Machining vs 3D Printing
During 5-axis machining, a machinist uses finishing tools to shape a workpiece in a desired way, usually by cutting away excess material. In the process of 5 axis machining, a workpiece will often undergo striking changes. For example, a software program in a 5 axis CNC machine may direct a cutting tool to create grooves and drilled holes to generate a finished component from a workpiece.
By contrast, during the entirely different process of 3D printing, a software program directs the automated construction of a desired shape using a powdered substrate and a specialized computer printer. Today, most 3D printers work with plastic materials, although some do allow the fabrication of metal items. Since 3D printing may require extensive time to complete, this manufacturing process does not yet compete commercially in most settings with machining.
5-Axis CNC Benefits
By using multi-axis machining techniques, a manufacturer can often obtain a more comprehensive finish on workpieces. Additionally, the automation provided by computer numerical control “CNC” technology usually permits faster production while also reducing the number of required machinists.
Instead of manually turning parts, human operators instead spend time supervising the performance of automated 5 axis machining equipment capable of performing on a 24/7 basis. While a manufacturer must still implement rigorous quality control operations, of course, software-directed CNC machining permits the production of uniform parts in large quantities. The generation of high volumes may justify the more significant capital investment in automated 5-axis CNC machinery.