Metalwork - Exam Papers - HL - Paper - 1993

100 Marks

INSTRUCTIONS

1. Answer Question 1, Sections A and B and three other questions.
2. All answers must be written in ink on the answer book supplied. Diagrams should be drawn in pencil.
3. Squared paper is supplied for diagrams as required.
4. Please label and number carefully each question attempted.

1.
(40 Marks)

SECTION A - 20 MARKS
COMPULSORY
Answer any five questions

(a) Describe briefly, any contribution made by an Irish man or woman to Technology.

(b) The diagram on the right shows part of a modern car engine. Name three of the parts A. B. C. D and E.

(c) What is the purpose of the grooves and rings in part A ?

(d) Explain the function of the shaft G.

(e) With the aid of a sketch, show how shaft G could be driven without slip by shaft E.

(f) An Electric Soldering Iron has the following speed specification :- 25W - 220V - AC. Explain the meaning of: 25W, 220V and AC.

(g) What is meant by the term "tapping size hole" ?

(h) Examine the electronic circuit shown. Name two components and slate the function of each.

SECTION B - 20 MARKS
COMPULSORY
Answer any five questions

The illustration shows an Electric Bell.

(a) Explain how the bell operates.

(b) Name a material which could be used to make part A.

(c) Describe how Part A is made.

(d) What material property is required for Part B ?

(e) Explain the purpose of the cores.

(f) The base can be made from either 6 mm Acrylic or 12 mm Hardwood. Select one of these materials for the base and

  1. name the tools necessary to make the base
  2. describe, using sketches, how the semi-circle is formed to shape.
2.
(20 Marks)

(a) Starting with the words "Design Brief", list any three other stages in the design process.

(b) A sign for Bed and Breakfast which is to be hung from a limber post is shown opposite. You are to design a decorative bracket which will hold the sign and allow it to be attached to the post in the position shown. Your design should :-

  1. Show clearly how the sign is attached to the bracket.
  2. Show how the bracket is attached to the post.
Rough sketches to illustrate your ideas and possible solutions should first be made in your answerbook. Select the most appropriate final solution and make a working drawing (elevation only) of your design on the squared section below.
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
3.
(20 Marks)
(a) Name the furnace illustrated on the right.

(b) List the materials used in the charge.

(c) Explain how the furnace is charged.

(d) What is the function of part F ?

(e) What is the function of parts C ?

(f) State the materials taken away in the rail cars D and E. Give one use of each of these substances.

(g) What type of lining is used in this furnace ?
4.
(20 Marks)
A Cement Mixer is shown in the illustration on the right.

(a) The large ring gear A is attached to the drum. It rotates at 50 rev / min and is driven by a small pinion gear wheel B. If the ring gear has 150 teeth and the pinion gear has 10 teeth, what is the gear ration ?

(b) At what speed does the small pinion gear wheel B rotate ?

(c) Name two methods of powering the mixer and state one advantage for each method.

(d) With the aid of a sketch, describe how the mixer shown could be modified so that it might be towed slowly by a car.

(e) What is the function of wheel C ?
5.
(20 Marks)

(a)

  1. Name three of the parts of the micrometer shown opposite.
  2. Explain the function of part A.
  3. What precautions should be observed both before and after using a micrometer ?
  4. What is the reading of the 0-25 mm micrometer shown ?


(b)

  1. What are "Vee" blocks ? Why are they usually supplied in pairs ?
  2. Show by means of a sketch how round material is held in position on a Vee block during the drilling operation.
6.
(20 Marks)
Answer SECTION A or SECTION B but not both.
 
SECTION A
Parts for a Locking Device for a bicycle are shown opposite.

(a) Part 1 is made from 12 mm diameter alloy steel. Calculate the length of material required to make this part.

(b) Show, by means of a diagram, how the slot A in Part 2 is formed.

(c) Explain how the device is assembled.

(d) On squared paper, draw a front elevation of the assembled Locking Device. Insert three dimensions on your drawing.

(e) Explain, with the aid of a sketch, how the semi-circle is formed in Part 1.

or


SECTION B


(a) In CNC / CAM, explain the importance of testing the programme before machining the component. (Test Run)

(b) Describe how an item is selected from an on-screen menu in either a CAD or a CNC programme.

(c) Name two ways in which information can be stored in a computer.

(d) What is the unit of Computer Memory ?

(e) Answer one of the following: -

  1. For what do the letters DOS stand ?
  2. What is meant by the term Tool Library ?
  3. Give one example of a code used in CNC and give its meaning.

(f) An alloy steel bar of diameter 30 mm is to be machined on a CNC lathe. Calculate the approximate spindle speed in rev / min for the lathe if the surface cutting speed of the alloy is 60 metres per minute.