Learning objectives: - Bigger picture: - Know about engineering processes used to produce modern engineered products Learning objectives: - Be able to explain what is meant by the term secondary machining Describe a range of secondary machining techniques Success criteria: - Provide a definition for different machining operations Correctly identify the sequence of machining for turning, milling and drilling.

Turning . . . Turning involves the use of the lathe to produce a given shape, usually cylindrical. Lathes have one thing in common: the work piece is held in a chuck and rotated while being machined to shape and size using a cutting tool.

Lesson task 1: Look at the common machining operations for lathe work Match up the operation with the description: Operation: Facing off Drilling Parallel turning Taper turning Parting off Description: A process used to cut off the work piece to the required length Removing material from the outer diameter of the work piece while maintaining the same size along its length Removing material from the end of a work piece to leave flat or square surface Removing material from the inside of a work piece using a drill bit A process used to create a conical shape by feeding a tool at an angle to the length of the work piece

Milling . . . Milling is a process used to shape products by removing excess material to produce a range of simple and complex shapes. A milling machine has a spindle that holds a rotating cutter in place. The work piece will be clamped to a table or held in a vice and fed under the cutter to form the desired shape. There are 2 main types of milling – horizontal and vertical.

Lesson task 2: Look at the common types of milling tools Match up the tool with the function: Operation: Face mills End mills Slot drills Slitting saws Description: Discs with saw teeth around the perimeter designed for cutting deep thin slots into the work piece A type of end mill designed to plunge into the work piece like a drill then be moved across to create a groove Cutter with multiple cutting tips – often called inserts – designed to move across the face of the work piece The most common tool used in milling, this has cutting teeth at one end and along the side

Drilling . . . Drilling is a process that creates circular holes in a work piece. The cutting device is called a drill bit. It usually has a shank that allows it to be held in a drilling machine. To drill a satisfactory hole in any material, the correct type of drill bit must be used. This is probably the most common machining operation you will perform. Good quality drill bits can be expensive but the key to good drilling is keeping the cutting edge sharp.

Lesson task 3: Look at the common types of drilling tools Match up the tool with the correct picture: Tool: Centre drill Tap Countersink Twist drill

Drilling The drill bit is placed into the chuck The chuck is tightened with a chuck key and the guard is positioned The work piece is clamped into a vice underneath the drill bit The drill is switched on The handle is slowly pulled down The drill bit is gradually forced through the material The lever is raised The drill is switched off Drilling

The tool is located in the tool holding device , tool post or tail stock The work piece is secured in the chuck, face plate or work holding device Coolant if required is switched on and directed onto the work piece Safety checks are undertaken, ensuring all guards are in place The tool is brought into contact with the work piece to produce the desired features The tool is removed from the work piece and a safe procedure is followed to shut down the machine Turning

Milling The tool is located in the chuck The work piece is secured in the work holding device If required coolant supply is switched on and directed onto the work piece Safety checks are undertaken including guards in place The tool is brought into contact with the work piece to produce the desired features The tool is removed from the work piece and a safe procedure is followed to shut down the machine Milling