The Milling Machine

Safety rules and Precautions:

Introduction:

Milling machines rotate at high speeds and therefore carries the risk of shavings and chips of metal flying all over the machine while it is operating. It is important to think safety at all times while operating the milling machine. Do not operate the machine if you are not familiar with the safety rules and precautions. The following is a guideline to operating the milling machine safely.

Wear the correct PPE (Personal Protective Equipment)

PPE include the following

• Safety glasse to protect your eyes against flying shavings metal chips
• Overalls or coats without long wide cuffs to protect clothes. (wide lose cuffs can get caught in rotating machinery) 
• Appropriate safety boots/footwear to protect feet against injury.
• A safety cap or hair net to cover long hair that can get caught in revolving machine parts.

Make sure all machine gaurds are in place

When operating a milling machine the operator must ensure that machine gaurds are in working order and in place on the machine. All workers in the workshop is safer with the machine gaurds in place.

Machine gaurds are normally put over all revolving machine parts, such as gear assemblies, motors and couplings. Some machines will not start if the machine gaurds are not in place.

Provide enough space around a clean work area

• Do not clutter the workspace with unnesessary equipment, tools and materials. 
• Keep the work area clean and dry.  Clean up coolant and oil spillage immediately 
• Allow enough space around the work area for loading and unloading of work.
• Demarcate areas for finished goods and raw materials
• Remove all chips, offcuts and shavings from the machining area.
• Tools and equipment must be stored in a storage area.
•  Keep the floor area clean, dry and oil free to prevent slippage and accidents.

General safety rules:

• Use Gloves when mounting Milling cutters. Milling cutters have sharp edges and wearing gloves prevents small cuts on fingers.
• Switch off the machine before loading or unloading workpieces to prevent injury by rotating cutters.
• Switch off the machine when you do measuring or cleaning.

Plan your work on the Milling Machine.

The following factors should be kept in mind when planning your work on a milling machine.

1. Spindle speed: This is the rotational speed of the cutting tool and it is measured in revolutions per second.
2. Tool diameter: The size of the cutting tool measured in diameter.
3. Feed rate: The rate at which the material is fed into the milling machine. This is measured in mm/min.
4. Cut depth: The amount of material that is cut away in one pass. This is measured in mm.
5. Surface cutting speed: the speed that each tool cut through the material. This is measured in m/mm

Diffirent cutters used on the Milling Machine.

On the Milling Machine you will use diffirent cutters to achieve diffirent cuts and finishes on a work piece. We will look at diffirent cutters but please note that you will find many more specialised cutters in the engineering environment.

1. End Mill Cutters: This is the most commonly used cutter to use on a milling machine. The cutter rotates on a vertical axis in relation to the workpiece but it can be tilted to produce tapered surfaces.
   
2. Face Cutters: These cutters rotate perpendiculer to the workpiece. It is mostly used for facing with cutting edge on the face and edge of the cutters.
   
3. Ballnose Cutters: These cutters have a round (ball or hemispherical) shape. They are used to form round grooves or three-dimentional shapes.
   
4. Slab cutter: The cutting teeth are on the uotside edge of the cutter and the cutter rotates parallel to the workpiece.
   
5.  Side and face cutter: This cutter has teeth on it side and Circumference which make it possible to cut on one side only.
   

Determining the cutting speed

The most common mistake made with cutting speed is a result of presure to produce. Using the correct cutting speed is important or else the milling machine, cutter or workpiece can be damaged with a loss in production time as result. Here is a typical recomended cutting speed chart.

Calculations for milling operations are being look at seperately so please browes the blog for more milling machine information.

Level 2 Fundamentals Test 2015

ENGINEERING FUNDAMENTALS

NQF LEVEL 2

QUESTION 1:  SA MANUFACTURING, ENGINEERING AND TECHNOLOGY

1.1	Careers in manufacturing, engineering and technology can be classified into categories. Name FOUR main categories of careers in manufacturing, engineering and technology.		(4)
1.2	What is a Code of Conduct in an engineering workplace?		(1)
1.3	Quality Work Life (QWL) refers to a person’s overall satisfaction with his or her working life. Name THREE elements of a good quality work life.		(3)
1.4	Choose a description from COLUMN B that matches a legislation in COLUMN A. Write only the letter (A – D) next to the question number (1.4.1 - 1.4.4) on your  ANSWER script.

			COLUMN A		COLUMN B
	1.4.1 1.4.2 1.4.3 1.4.4		Employment Equity Act (EEA) Labour Relations Act (LRA) Basic Conditions of Employment Act(BCEA) Skills Development Act (SDA)	A B C D	the Act will make the employees more productive and will help  to make the business successful the Act gives rules for the relationship between employer and employee and to support the rights and responsibilities of employees and employers the Act promotes equal opportunity and fair treatment in employment through the elimination of unfair discrimination the Act protects employees by giving them a right to fair labour practices by laying down rules for basic conditions of employment, such as sick leave and annual leave.
					4x1			(4)
1.5		What is understood by work ethics?					(2)
1.6		You are a supervisor in a manufacturing company and one of your juniors did not follow a code of conduct. What steps will you take or use to discipline him/her?					(5)
1.7		Give ONE reason why an employee joins a trade union.					(1) [20]

QUESTION 2 : SAFETY PRACTICES IN THE ENGINEERING WORKPLACE

2.1

Indicate whether the following statements are TRUE or FALSE. Choose the answer and write only 'true' or 'false' next to the question number (2.1.1 -2.1.5) in the ANSWER BOOK.

2.1.1 2.1.2 2.1.3 2.1.4 2.1.5

Good housekeeping improves productivity and workmanship. Prohibitory signs tell people about actions that are not allowed at a specific area. Warning signs are signs that give you general information. Color codes are often used to define demarcated areas. Machine guards are fitted to machines to protect workers from moving parts of the machines.

(1) (1) (1) (1) (1) (5)

2.2

List FIVE safety precautions to be kept in mind when using a bench or pedestal grinder.

(5)

2.4

Name TWO types of machine guards that are used on machines in the industry.

(2) [15]

QUESTION 3: BASIC FIRE FIGHTING

3.1	Name the FOUR  essential elements that must be present for a fire to keep burning		(4)
3.2	Describe FOUR types of fires that can start in the workplace.		(4)

3.3	State TWO conditions that can cause fires.				(2)
3.4	The following steps on how to use a fire extinguisher are NOT in the correct order. Arrange and write them on your  ANSWER  SCRIPT in the correct order. Write only the answer next to the question number (3.4.1 – 3.4.4).
	3.4.1 3.4.2 3.4.3 3.4.4		Squeeze the handle to release the extinguishing agent. Move the extinguisher from side to side so that you cover the whole area. Pull out the pin at the top of the extinguisher to break the seal. Aim the extinguisher nozzle at the base (the bottom) of the flames.		(1) (1) (1) (1) (4) [14]

QUESTION 4: BASIC FIRST AID.

4.1 4.2 4.3 4.4	What is first aid? What is the primary duty of a first aider? Give THREE symptoms of shock. What is the difference between dressing and a bandage?		(3) (3) (3) (2) [11]
TOTAL			60

MARKING GUIDELINES. ENGINEERING FUNDAMENTALS LEVEL 2

1.1	• Extraction – based careers.  • Installation – based careers.  • Maintenance – based careers.  • Manufacturing – based careers.				(1) (1) (1) (1) (4)
1.2 1.3	A code of conduct is a written set of rules explaining how workers must behave in the workplace. • Good safety regulations. • A fair salary. • A healthy work environment. • Reasonable working hours. • Not too much stress.                                                                ( ANY THREE FACTS)				(1)  (1) (1) (1) (1) (1) (3)
1.4	1.4.1 1.4.2 1.4.3 1.4.4	1 – D 2 – B 3 – A 4 – C		(1) (1) (1) (1) (4)

1.5

Work ethics refers to the way we behave at work. It is about our attitude towards our work, fellow workers and our supervisors

(2)

1.6	(a) (b)  (c)   (d)  (e)	Counseling  Verbal warning  Written warning  Final written warning  Summary of dismissal		(1)  (1)  (1)  (1) (1) (5)
1.7	·  ·  ·	Workers feel that they are stronger as a group and can protect themselves from powerful employers who might not treat them fairly. Workers want to be paid well and feel that the unions will be able to get better wages for them. Workers feel more secure in their jobs when belong to a trade union and can protect them if they are dismissed unfairly.                                                                                      (ANY FACT)		(1) (1) (1) (1) [20]

QUESTION 2: SAFETY PRACTICES IN THE WORKPLACE

2.1 2.2

2.1.1 2.1.2 2.1.3 2.1.4 2.1.5 ·  ·  ·  ·  ·  ·  ·  ·

True False False True True Always wear safety goggles or face shield when using a pedestal or bench grinder. Always use wheels that are rated consistent with the speed rating of the pedestal or bench grinder. Only dress the face of the wheel with a suitable wheel dresser. Never use a wheel that vibrates Never start a grinder with a work piece against the wheel Keep your hand and fingers at least 50mm away from the rotating wheel.  Cool the work piece by dipping it in water. Do not apply coolant water directly onto the wheel. Always clean the pedestal or bench grinder work areas upon completion of a grinding task.                                                                       (ANY FIVE FACTS)

(1)  (1)  (1)  (1)  (1)  (5)  (1) (1) (1) (1)  (1) (1) (1) (1) (5)

2.3

·  ·  ·  ·  ·  ·

Protection signs WW- Warning signs FB-Fire Equipment warning signs PV- Prohibitive signs GA- Informative signs MV- Safety clothes and equipment to be worn                                                                      (ANY THREE FACTS)

(1) (1) (1) (1) (1) (1) (3)

2.4

·  ·  ·  ·  ·

Fixed Guards Interlocking Guards Automatic Guards Distance Guards Trip Guards                                                                      (ANY TWO FACTS)

(1) (1) (1) (1) (1) (2) [15]

QUESTION 3 : BASIC FIRE FIGHTING

 

3.1	·      Heat ·      Oxygen  ·      Fuel ·      Chemical Reaction			(1) (1) (1) (1) (4)
3.2	·  ·  ·  ·  ·	Class A – ordinary materials such as paper, wood, textiles, grass. Class B – flammable liquids such as petrol, alcohol, paraffin. Class C – live electrical installations, such as cables, generators. Class D – metals that burn at high temperatures, e.g. Sodium. Class E – high pressure flammable gasses such as propane.                                                                        (ANY FOUR FACTS)		(1) (1) (1) (1) (1) (4)

3.3

·  ·  ·  ·  ·  ·

Electrical faults Open flames Chemicals reactions Hot surfaces Friction Lighting                                                                           (ANY TWO FACTS)

(1) (1) (1) (1) (1) (1) (2)

3.4

3.4.1 3.4.2 3.4.3 3.4.4

Pull out the pin at the top of the extinguisher to break the seal. Aim the extinguisher nozzle at the base (the bottom) of the flames. Squeeze the handle to release the extinguishing agent. Move the extinguisher from side to side so that you cover the whole area.

(1) (1) (1) (1) (4) [14]

QUESTION 4: BASIC FIRST AID.

4.1

First aid is the emergency care given- to an injured person Or suddenly ill person- using readily available materials

(3)

4.2

·  ·

To Preserve and sustain life (To safe life) To Prevent casualty’s condition from becoming worse To Promote casualty’s recovery

(1) (1) (1) (3)

4.3

·  ·  ·  ·  ·  ·

Weak.  Nauseous.  Frightened.  Restless.  Thirsty.  Disorientated                                                                        (ANY THREE FACTS)

(1) (1) (1) (1) (1) (1) (3)

4.4

·  ·

Dressing is a covering on a wound A bandage is any kind of materials that holds a dressing in place                                                                                                                                                                                                                                                                                                                                                                     TOTAL:

(1) (1) (2)  [11] [60]