NATIONAL CERTIFICATE (VOCATIONAL) ENGINEERING TECHNOLOGY NQF LEVEL 2 NOVEMBER 2010

Transcription

1 NATIONAL CERTIFICATE (VOCATIONAL) ENGINEERING TECHNOLOGY NQF LEVEL 2 NOVEMBER 2010 ( ) 24 November (X-Paper) 09:00 12:00 This question paper consists of 10 pages and 1 annexure.

2 ( ) -2- NC920(E)(N24)V TIME: 3 HOURS MARKS: 100 INSTRUCTIONS AND INFORMATION Answer ALL the questions. Read ALL the questions carefully. Number the answers according to the numbering system used in this question paper. ALL sketches must be neat, clear and in proportion. ALL work which you do not want to be marked must be clearly crossed out. Start each question on NEW page. Write neatly and legibly.

3 ( ) -3- NC920(E)(N24)V QUESTION Indicate whether the following statements are TRUE or FALSE. Write only 'true' or 'false' next to the question number ( ) in the ANSWER BOOK A hammer must be used to strike the handle of a vice when tightening it. A belt and cone pulley system on a pedestal drilling machine is used to adjust the speed of the drilling machine. A tape measure can be used to check the squareness of a large work piece. An inside micrometer is used to accurately measure the inside diameter as well as the inside measurement of two parallel surfaces. A centre or dotting punch is used to drive out pins. (5 1) [5] 1.2 Choose a description from COLUMN B that matches the item in COLUMN A. Write only the letter (A F) next to the question number ( ) in the ANSWER BOOK. COLUMN A COLUMN B Spanner Masonry drill bit Telescopic gauge A B a quick and accurate means of checking inside measurements unit of measurement expressed as Pascal Pressure Odd-legcallipers (Jenny) C D used to drill trough concrete, brick and stone used for tightening or loosening nuts and bolts E used to draw parallel lines or to find the centre of a round work piece F used to tighten screws (5 1) [5]

4 ( ) -4- NC920(E)(N24)V 1.3 Complete the following sentences by using the words in the list below. Write only the word(s) next to the question number ( ) in the ANSWER BOOK. outside micrometer; depth micrometer; hammer action; tap; centre punch; pin punch A is a tool used to cut internal threads in a drilled hole. The switch is only used when drilling into concrete, brick or other masonry materials. is mainly used to measure the outside diameter or external size of an object. The is supplied with a number of interchangeable rods for accurately measuring different depths. A is used to mark the centre of holes to be drilled. (5 x 1) (5) [15] QUESTION 2 You are asked to manufacture the MACHINE BLOCK (FIGURE 1) below. Study the diagram and answer the questions that follow. C (slots) W A (hole) φ 8 M10 B L FIGURE 1

5 ( ) -5- NC920(E)(N24)V 2.1 Name the power tool that you would use to obtain an accurate hole of diameter 8 mm at point A. HINT: The use of a portable drilling machine is NOT allowed due to the high accuracy needed. 2.2 Describe TWO safety aspects related to the power tool which will be used in QUESTION Explain what is meant by the term M10 as indicated at point B. 2.4 After the hole has been drilled to the correct size at point B (M10), name the hand tools that you would require to make the hole in QUESTION Explain what will happen if the drilled hole at point B is too small too big. 2.6 Name the hand tool used to cut the slots at point C. 2.7 Describe TWO safety aspects to consider when using the hand tool in QUESTION Using a ruler, take the following measurements of the MACHINE BLOCK in FIGURE 1. QUESTION Length (L) Breadth (B) Width (W) [14] 3.1 Study FIGURE 2 below and describe what is wrong with the chisel with respect to the cutting edge and head. FIGURE 2

6 -6- ( ) NC920(E)(N24)V 3.2 What would you do to correct the faults on the chisel? 3.3 Make a neat, labelled sketch of an engineer s square. (3) 3.4 State the function of a thread pitch gauge. 3.5 Name parts and on the inside micrometer in FIGURE 3 below FIGURE State ONE function of a clock gauge. 3.7 State TWO ways in which you would care for and store a vernier calliper. [14] QUESTION An operator is doing maintenance on the machne in FIGURE 4 below. Study the photo and answer the questions that follow. A FIGURE Name the machine in FIGURE Explain what task is being carried out in FIGURE Name tool A that is used to carry out the maintenance task in FIGURE 4.

7 ( ) -7- NC920(E)(N24)V 4.2 Name the protective equipment that must be used when drilling a work piece. 4.3 Copy TABLE 1 in your ANSWER BOOK and place each of the following power tools in the correct column according to the power source used to operate it. Power saw Impact wrench 10 ton press Hydraulic Electrical Pneumatic TABLE 1 (3) 4.4 State ONE function of a tape measure. 4.5 State the full names of the following SI units of measurement: mm mg 4.6 Convert 120 minutes to hours. 4.7 Calculate the weight of an object which has a mass of 68 kg. 4.8 Convert 120 MPa to Pa (Pascal). [14] QUESTION Analyse FIGURE 5. Determine whether or is the correct way of using the adjustable spanner FIGURE 5

8 ( ) -8- NC920(E)(N24)V 5.2 Name the following hand tools: Explain, with regard to your safety, the consequences of using a file without a handle. 5.4 Explain how the speed of a pedestal drilling machine (driven by V-belts) can be changed. 5.5 Name THREE methods of clamping a work piece to the machine table when using a pedestal drilling machine. (3) 5.6 What is the purpose of a ring test which is conducted on a grinding wheel? 5.7 State ONE function of each of the following power tools: Vertical band saw Hydraulic press 5.8 Make a neat drawing of only the barrel and thimble of an outside micrometer showing a measurement of 10,88 mm. [14] (3)

9 ( ) -9- NC920(E)(N24)V QUESTION Name measuring instruments and Study FIGURE 6 below and answer the questions that follow. FIGURE Name the measuring instrument used in FIGURE Describe the work carried out in FIGURE Name any THREE parts of a combination set. (3) 6.4 Name marking-off instruments and below

10 ( ) -10- NC920(E)(N24)V 6.5 Name any THREE marking-off media. (3) 6.6 State TWO ways of caring for and maintaining a centre or dotting punch. [14] QUESTION 7 FIGURE 7, ANNEXURE 1 (attached), is an isometric view of a machine part. Draw, to scale 1:1 and in first-angle orthographic projection, the following: 7.1 A front view (A) (3) 7.2 A top view (B) (4) 7.3 A left view (C) (3) 7.4 Insert ONE dimension per view. (3) 7.5 Insert the projection symbol in the space below the left view. [15] TOTAL: 100

11 ( ) -11- NC920(E)(N24)V ANNEXURE 1 B C A FIGURE 7