Computer numerical control (CNC) milling is a subtractive machining technique that achieves the desired part shape using computerized controls and rotary, multi-point tooling. While the earliest milling machines were manually operated, most of today’s milling processes use advanced, computer-controlled CNC mill machining centers to maximize accuracy and efficiency. JTV Manufacturing, Inc. provides CNC milling as part of our extensive service offerings to support our commitment to precision and excellence in all we do.
CNC Milling Process
Although CNC milling is a common secondary process to add finishing features to a part, it can also create finished, usable components out of raw materials for full production capabilities. The optimal type of milling equipment, design software, and cutting tools will vary depending upon a workpiece’s material and the part design. However, milling processes will typically involve:
- CAD model design and conversion. First, the operator uses computer-aided design (CAD) software to generate a 2D or 3D model of the part. Once complete, computer-aided manufacturing (CAM) software receives the design and converts it into a program compatible with the CNC equipment, essentially translating the needed operations for the CNC machine to direct and control its actions.
- Machine preparation. The operator prepares the milling equipment by securing the workpiece to the worktable, vise, or similar holding component. The required cutting tools are then selected and affixed to the spindle.
- Process execution. After programming the design instructions and setting up the equipment, the machinist initiates the milling process. The cutting tool will progressively and selectively cut material away from the workpiece, rotating at speeds as high as thousands of RPMs for fast, efficient precision machining.
Types of CNC Milling Machines
Milling machines are available in several types, with common equipment including:
- Knee-Type CNC Milling Machines
Knee-type milling machines are vertical mills equipped with stationary spindles and worktables that move along the vertical (Y) axis. The knee provides support to the saddle, which holds the vertically adjustable worktable. - Ram-Type CNC Milling Machines
With ram-type milling machines, a spindle mounted to the movable housing, or ram, on the machine’s column enables the cutting tool to travel along the horizontal (X) and vertical (Y) axes. - Bed-Type CNC Milling Machines
The worktable on bed-type milling equipment is attached right to the bed of the machine, restricting the workpiece’s movement along the Y and Z axes to provide longitudinal movement only. The movable spindle, however, may move tooling along X, XY, or XYZ axes, depending on the machine. - Planer-Type CNC Milling Machines
Similar to bed-type equipment, planer-type milling machines feature a fixed worktable on the Y- and Z-axis, with a spindle that moves the tooling along the X-, Y-, and Z-axis. They are unique, however, in that they can utilize as many as four machining tools at once for added speed and efficiency.
CNC Milling Machine Materials
The versatility of CNC milling makes it suitable for machining virtually any material with sufficient hardness. Choosing the best material for your project involves careful consideration of several factors, including the part design, the specific milling equipment being used, and the conditions of the application. Examples of materials that are compatible with the milling process include:
- Metals, including alloys, exotic materials, and hard and heavy-duty metals
- Plastics, including thermoplastics and thermosets
- Elastomers
- Ceramics
- Composite materials
- Glass
CNC Milling Machines at JTV Manufacturing
As a contract manufacturer with in-house CNC milling and turning capabilities, JTV Manufacturing is equipped to meet a wide range of design requests and production needs. Below is a list of the machines we use for these processes in our 85,000-sqft. facility, along with a description of their features.
