A milling machine is a mechanical machine that is used in heavy-duty milling of wood, metal, and many more solid materials. Due to the structural and operational differences, this machine is highly helpful in every machine shop. The following are the most prevalent milling machines that are used in the industry.
Type Of Milling Machine
- Ram Turret Milling Machine
- Knee Type Milling Machine
- Bed Milling Machine
- Horizontal Milling Machine
- Universal Milling Machine
Ram Turret Milling Machine
The ram-type milling machine is characterized by a spindle mounted to a movable housing on the column to permit positioning the milling cutter forward or rearward in a horizontal plane. Two popular ram-type milling machines.
Knee Type Milling Machine
Knee-type milling machines are characterized by a vertically adjustable worktable resting on a saddle that is supported by a knee. The knee is a massive casting that rides vertically on the milling machine column and can be clamped rigidly to the column in a position where the milling head and milling machine spindle are properly adjusted vertically for operation. The plain vertical machines are characterized by a spindle located vertically, parallel to the column face, and mounted in a sliding head that can be fed up and down by hand or power. Modern vertical milling machines are designed so the entire head can also swivel to permit working on angular surfaces, The turret and swivel head assembly is designed for making precision cuts and can be swung 360° on its base. Angular cuts to the horizontal plane may be made with precision by setting the head at any required angle within a 180” arc.
The plain horizontal milling machine’s column contains the drive motor and gearing and a fixed position horizontal milling machine spindle. An adjustable overhead arm containing one or more arbor supports projects forward from the top of the column. The arm and arbor supports are used to stabilize long arbors. Supports can be moved along the overhead arm to support the arbor where support is desired depending on the position of the milling cutter or cutters.
The milling machine’s knee rides up or down the column on a rigid track. A heavy, vertical positioning screw beneath past the milling cutter. The milling machine is excellent for forming flat surfaces, cutting dovetails and keyways, forming and fluting milling cutters and reamers, cutting gears, and so forth. Many special operations can be performed with the attachments available for milling machine use. The knee is used for raising and lowering. The saddle rests upon the knee and supports the worktable. The saddle moves in and out on a dovetail to control the cross feed of the worktable. The worktable traverses to the right or left upon the saddle for feeding the workpiece past the milling cutter. The table may be manually controlled or power fed.
Bed Type Milling Machine
A bed-type milling machine is generally made out of a stable, generally, low-vibration machine bed, upon which the workpiece is placed. A variety of clamping methods are used for the workpiece, including a clamping slot and a clamping claw, and the corresponding screws. The clamping device of a bed milling machine can be mechanical, hydraulic, electric, or implemented using compressed air. These kinds of milling machines allow large and heavy workpieces to be processed without risk of tipping, as opposed to the quick clamping devices. For the most part, the machine bed serves as the machine table at the same time, thus ensuring a low-vibration process and increasing the durability of the cutting edge. Additionally, a bed-type milling machine contains one or two machine stands that store the tool units. This means that components can be processed per clamping.
Horizontal Milling Machine
A horizontal mill has the same sort, but the cutters are mounted on a horizontal spindle across the table. Many horizontal mills also feature a built-in rotary table that allows milling at various angles; this feature is called a universal table. While endmills and the other types of tools available to a vertical mill may be used in a horizontal mill, their real advantage lies in arbor-mounted cutters, called side and face mills, which have a cross-section rather like a circular saw but are generally wider and smaller in diameter. Because the cutters have good support from the arbor and have a larger cross-sectional area than an end mill, quite heavy cuts can be taken enabling rapid material removal rates. These are used to mill grooves and slots. Plain mills are used to shape flat surfaces. Several cutters may be ganged together on the arbor to mill a complex shape of slots and planes. Special cutters can also cut grooves, bevels, radii, or indeed any section desired. These specialty cutters tend to be expensive. Simplex mills have one spindle, and duplex mills have two. It is also easier to cut gears on a horizontal mill. Some horizontal milling machines are equipped with a power-take-off provision on the table. This allows the table feed to be synchronized to a rotary fixture, enabling the milling of spiral features such as hypoid gears.
Universal Milling Machine
Is a milling machine with the facility to either having a horizontal spindle or a vertical spindle. The latter sometimes being on a two-axis turret enabling the spindle to be pointed in any direction on desires. The two options may be driven independently or from one motor through gearing. In either case, as the work is generally placed in the same place for either type of operation, the mechanism for the method not being used is moved out of the way. In smaller machines, ‘spares’ may be lifted off while larger machines offer a system to retract those parts, not in use.