Page 95 - CITS - Fitter - Trade Theory

FITTER - CITS

7 Control of Machine Movements: The movement of the cutting tool and workpiece is controlled by the milling
machine’s axes of motion, which include the X-axis (horizontal), Y-axis (vertical), and Z-axis (depth). These
axes allow for precise positioning and movement of the cutting tool relative to the workpiece to create the
desired features and shapes.
8 Complex Machining Operations: Milling machines are capable of performing a wide range of machining
operations, including face milling, end milling, slotting, drilling, boring, contouring, and thread milling. Complex
machining operations involve coordinated movements of the cutting tool along multiple axes to create intricate
geometries and features.
9 Surface Finish and Accuracy: The milling machine’s rigidity, precision, and control systems contribute to the
achievement of high surface finish and dimensional accuracy in machined components. Proper selection of
cutting tools, machining parameters, and machine setup ensures consistent and reliable machining results.
10 Quality Control and Inspection: Machined components are inspected using precision measurement tools
such as micrometers, calipers, and coordinate measuring machines (CMMs) to verify dimensional accuracy
and compliance with specifications. Quality control measures ensure that machined parts meet quality
standards and customer requirements.
Parts of milling machine:
1 Base: The base is the foundation of the milling machine, providing support and stability to all other components.
It is usually made of cast iron or welded steel and provides a rigid platform for the entire machine.
2 Column: The column is a vertical structure mounted on the base and supports the other machine components
such as the spindle, table, and saddle. It may contain guideways or tracks to allow vertical movement of the
saddle along the column.
3 Saddle: The saddle is a movable component that travels vertically along the column. It supports the table and
provides the means for precise positioning of the workpiece during machining operations.
4 Table: The table is a flat, horizontal surface mounted on the saddle and supports the workpiece during
machining. It may have T-slots, clamping fixtures, or rotary tables for securing the workpiece in position.
5 Spindle: The spindle is the main rotating component of the milling machine and holds the cutting tool. It is
mounted vertically or horizontally depending on the type of milling machine and rotates at high speeds to
remove material from the workpiece.
6 Spindle Motor: The spindle motor provides the power necessary to rotate the spindle and cutting tool at the
required speeds. It may be an electric motor, geared motor, or other types of drive mechanisms depending on
the machine’s design and capabilities.
7 Tool Holder: The tool holder is a component that holds and secures the cutting tool in place during machining
operations. It may be a collet, chuck, or tool holder, and ensures proper tool alignment and concentricity with
the workpiece.
8 Guideways: Guideways are precision-machined surfaces that guide the movement of the saddle and table
along the column and base, respectively. They ensure smooth and accurate motion of machine components
and help maintain machining accuracy and repeatability.
9 Control Panel: The control panel contains the machine’s control interface, including switches, buttons, and
indicators for operating the machine. It may include manual controls for adjusting spindle speed, feed rate, and
axis movement, as well as digital displays or readouts for monitoring machining parameters.
10 Coolant System: A coolant system is often integrated into the milling machine to lubricate and cool the cutting
tool and workpiece during machining. Coolant helps reduce heat generation, chip formation, and tool wear,
resulting in improved machining efficiency and surface finish.

11 Power Drive Mechanism: The power drive mechanism provides the means for driving the spindle and moving
the saddle and table during machining operations. It may consist of electric motors, gears, belts, or hydraulic/
pneumatic systems, depending on the machine’s design and capabilities.

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CITS : CG & M - Fitter - Lesson 12