1. Six factors that determine the selection of tools for machining operations are:
a) Material being machined: Different materials require specific cutting tools to achieve optimal results. Harder materials may require harder and more durable cutting tools.
b) Cutting conditions: Factors such as cutting speed, feed rate, and depth of cut influence tool selection. Different tools are suitable for different cutting conditions.
c) Desired surface finish: The required surface finish affects the choice of cutting tools. Finer surface finishes may require specific tool geometries or coatings.
d) Tool life: The expected tool life impacts the selection of cutting tools. Longer tool life may be preferred to reduce tool change frequency and associated downtime.
e) Cost: The cost of cutting tools is considered in tool selection. Balancing performance and cost is essential.
f) Machining operation: Different operations may require specific tool types. For example, milling, turning, drilling, etc., each require specialized tools.
2. Five operations that can be carried out on a lathe machine are:
a) Turning: Removing material from the outer diameter of a workpiece to create a cylindrical shape.
b) Facing: Creating a flat surface on the end of a workpiece.
c) Drilling: Creating holes in the workpiece.
d) Boring: Enlarging or refining existing holes in the workpiece.
e) Thread cutting: Creating internal or external threads on the workpiece.
3. A machine tool is a power-driven device used for shaping or machining metal or other rigid materials. It provides the necessary controlled movements and forces to perform various machining operations accurately and efficiently.
4. Six types of machine tools are:
a) Lathe machine: Used for turning operations.
b) Milling machine: Used for milling operations, such as cutting, drilling, and shaping materials.
c) Drilling machine: Used for creating holes in materials.
d) Grinding machine: Used for grinding and smoothing surfaces.
e) Shaping machine: Used for shaping flat or curved surfaces.
f) CNC machine: Computer Numerical Control machines that automate various machining operations.
5. Drilling is carried out on a drilling machine by rotating a cutting tool called a drill bit and applying axial force to create a hole in the workpiece. The drill bit is held in a spindle, and the workpiece is clamped securely. The drilling machine is operated by lowering the rotating drill bit onto the workpiece while applying pressure. The drill bit removes material and creates a hole of the desired diameter and depth.
To generate flat surfaces on a lathe machine, a tool called a facing tool or facing cutter is used. The facing tool is held in the tool post and is fed perpendicular to the workpiece's rotational axis. The tool is advanced along the workpiece's surface, removing material and creating a flat surface. The lathe machine's cross-slide and carriage movements control the depth and width of the cut, allowing for precise and accurate surface generation.