LGCSE DESIGN AND TECHNOLOGY 0189 REPORT FOR TEACHERS

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Sabrina Hutchinson
5 years ago
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1 LGCSE DESIGN AND TECHNOLOGY 0189 REPORT FOR TEACHERS The 2016 Design and technology Paper was composed of 16 questions of which 10 of them formed part A and were compulsory and contributed 28 marks. These were general short answer questions. Part B was composed of two sections; Section 1 was based on tools and materials. There were three questions which carried equal marks, on which candidates were to answer two from the three questions. Section 2 also had three questions from which candidates had to answer any two. All questions were based on processes and carried equal marks. Question 1 required candidates to name two main groups of natural timber; The expected responses were; Hardwood and softwood. Most candidates provided the correct responses except few who mentioned any two softwoods or any two hardwoods. Question 2 was based on a table which candidates were to copy and complete: TOOL Ratchet brace Plough plane USE Planning curves on wood Expected response for toll was spoke shave Use of Ratchet brace; To hold bits when boring holes e.g. on confined spaces Use of plough plane; Marking grooves and rebates on softwoods. Most candidates provided curve cutting tools instead of curve planning tools. On the Ratchet brace majority of them said it was used for boring holes. Only a few candidates gave the correct response while others just stated the use of other planes that they know e.g. Block plane, smoothing and Jack plane. Question 3 required candidates to give two reasons why polystyrene is used for packaging. Expected responses were; Shock absorption light weight and easy to form into different shapes. Most candidates were able to mention only one reason which is light in weight few were able to state two correct reasons while others stated reasons which were irrelevant to packaging such as does not easily loose heat.

2 Question 4 was divided into sub-sections a and b. In a candidates were to state two uses of copper and in b they were to state two working properties of copper. a Expected responses; electric wires, water pipes, soldering bit head etc. Here most candidates gave correct responses. b Expected responses; ductile, good conductor of both heat and electricity. A lot of candidates provided the correct answers, except few who confused uses and properties. Question 5 showed three workshop tools and candidates were to name them. Tool A was coping saw, tool B a Try Square and tool C Odd Leg Calipers. A lot of candidates were able to name the tools correctly. Question 6 was divided into sub-sections a and b in a candidates had to give two working properties of plywood and in b, they were to state two methods of joining wood temporarily together. Expected responses for a stable, remains flat in any working condition, does not easily split etc. This part was well responded to by majority of candidates except a few who provided uses. Expected responses for b screwing, bolds and nuts, nailing and joints etc. Here candidates generally responded well. Question 7 was composed of two parts a and b. Candidates were to provide two safety precautions observed during grinding of metal and during cutting of plastic with hot wire cutter. Expected response on grinding; use of safety goggles, leather gloves, eye shield, and apron etc. A lot of confusion was observed here as most candidates referred to angle grinder. Expected precautions for use of hot wire cutter; wear leather gloves, respirator and ensure a well ventilated place. Most candidates were too general when providing answers e.g gloves instead of specifically mentioning leather gloves. Question 8 required candidates to give two safety precautions observed when using a hammer.

3 Expected responses were; never use a hammer with loose head/handle, do not use a hammer with a mushroom head. Most candidates provided correct responses in this question. Question 9 required candidates to give two uses of stainless steel. Expected response; making of surgical instruments, kitchen utensils, steel rule, jewelry etc Almost all candidates were able to respond accordingly. Question 10 Candidates were expected to state the use of (a) rivet set and snap, (b) hacksaw Expected responses; (a) rivet set is used for pressing/pulling pieces of metal together while the rivet snap forms the snap head. Most candidates did not know the use of the tool and therefore provided many different uses which were irrelevant. Expected responses; (b) cutting metals at any direction in their cold condition and also for cutting some plastics e.g. Acrylic. PART B Question 11 was based on figure 1 which showed two bits A and B (a) Candidates were to name and state the use of each bit. Expected responses were; A Center bit is used for boring holes up to 50mm, marking/starting centres for twist bits and also for boring shallow holes. B twist drill is used for boring holes in wood, metal and plastic. (b) (i) Candidates were to show how tool A could be used to make a smooth hole through a 20mm thick piece of hardwood. (ii) Here candidates were to state the effects of using a centre bit with; 1. Broken centre screw, 2. Broken cutting spur. In (i) candidates were expected to show method of holding work piece including showing of waste piece cramped to the back of the work piece. This was to be clearly shown using sketches. (ii) 1 Effects may include a hole which is not true or even bigger in size.

4 2 The hole will not be proper; too much pressure may result in injuries. Question 12 was from a stem which showed three different workshop tools A, B and C. (a) Candidates were to name and state the use of each tool shown. (b) Name the materials that are used to make the handle and body of tool A (c) Explain how to protect wood when shooting end grain using tool B (d) Candidates were to name process used to make the rough feature on tool C the spring dividers. (e) (i) candidates were to state two precautions to be observed when using tool A Expected response in; (ii) State two precautions to be observed when storing tool B. (a) Tool A flat file is used for finishing edges of work piece after cutting e.g. metal (b) Material for the handle could be plastic/wood (hickory/ash) and the body cast steel (c) Planning from the alternative side of the work piece or putting a waste piece at the edge of the work piece (d) The process to make the feature on tool C is knurling and the purpose for knurling is for finger grip. (e) (i) Safety precautions in relation to the use of tool A do not use a file without handle, do not a file on hardened steel and never drop a file as it is brittle. (ii) Safety precautions to observe when storing tool B The must be stored on its side to avoid the blade from getting gaped or leaving dents on the workbench, oiling the sole slightly to avoid rust, not storing it mixed with other tools to avoid blade becoming damaged.

5 This was the most popular question in this section and candidates really attempted it fairly well as compared to other questions. Tool B is the tool that candidates confused it to be smoothing plane. Question 13 (a) Copy and complete the table below. Material Properties uses Polypropylene Polyester resin Acrylic (b) Candidates were to name two main types of plastics. (c) Explain the term plastic memory. (d) Name any two methods of moulding plastics. (e) Give two advantages of using plastic over hardwood. (f) Name a specific plastic plastic for; (i) Cooker knob, (ii) Insulating electric cable. Expected responses in the table; (a) Material Properties Uses Polypropylene Hard and chemical resistant Kitchen ware, toys, syringes Polyester resin Resistant to ultra violet light, takes colour well Boat making, car bodies, canoes and roofing. Acrylic Easily shaped, machines easily Sign boards, car light cover, ceiling panels

6 Most candidates seemed to be familiar with only acrylic, its properties and uses. As for the other two plastics they just gave any use and property which were not relevant to the specific plastics. (b) Candidates were able to name thermoplastic and thermosetting plastics as well as their properties. (c) Expected definition of plastic memory ability of plastic to soften under heat even after moulding and then return to its state. About half of the candidates who attempted this question did not know plastic memory and ended up writing anything about plastics, including why plastics are used. (d) Expected methods of moulding plastics included; Blow moulding, extrusion and injection moulding. This question was well performed as almost all candidates got it correct. (e) Expected responses; light in weight, easy to clean, non-toxic and colourful Candidates were familiar with advantages of plastics and responded accordingly. (f) (i) Bakelite (ii) Plasticized P.V.C (Polyvinyl Chloride) Here only a few candidates were able to name correct plastics whereas others just stated any plastic they knew. Question 14 This question was based on a shaped wooden candle holder stand and sheet metal holder. (a) Name the process of shaping the holder stand. Expected response was turning on a lathe Candidates responded correctly well on this part. (b) Name the machine used for shaping the stand. Expected response was wood turning lathe. Candidates also responded well to this question. Candidates were to use notes and sketches to show how a wooden piece is marked out

7 before shaping as show on the stand. Expected response; marking centres on both ends, boring small holes on centres. Candidates did not show marking but showed mounting the work piece, sketches were Were also poor. Therefore this part was not well responded. (c) Candidates were to use notes and sketches to show three main stages of mounting the Work piece on the wood turning lathe. Expected response; locating centres, boring centres, securing work piece between Centres and tightening the work piece. Candidates showed piece already held on the machine, not step on how to mound it. (d) State two safety precautions when using the machine named in (b) Expected responses included use of nose bags, no loose clothing, use of aprons and Safety goggles. Most candidates responded well to this part of the question. (e) Use notes and sketches to show how the sheet metal holder and wax tray are made and joined together. Expected response involves marking out surface development of the holder and shaping it into a cylinder. Marking out the wax tray using spring dividers to obtain a circle, use of bossing mallet or doming hammers to shape it. The pieces could be joined together by grazing or soldering etc. Majority of candidates confused the processes involved in marking out and making the holder and the wax tray and they also used incorrect methods of joining them together. Question 15 was based on a sketch showing a house name plate. The name plate was enclosed in a wooden block and made from 2mmmm thick sheet plate. (a) Name a suitable material for making the 2mm thick sheet plate and give two reasons for your choice.

8 Expected materials; Acrylic, Copper, Aluminum etc. Reasons for choice Acrylic; easy to clean, water proof, easy to work with. Copper; cleans well, polishes well, light in weight. Aluminum; cleans well, easily machined and light in weight. (b) (i) Using material of your choice, use notes and sketches to show how the sheet plate is made from the 2mm thick material. Expected response includes marking out and cutting using correct tools and finishing edges correctly. (ii) Use notes and sketches to show how the writing of the name is done on the 2mm thick sheet plate. Expected responses would include, embedding, use of scroll saw to cut out the letters, painting, and etching using sulphuric acid. Cut different letters from another material and mount them on the sheet plate. All processes to be shown using clear sketches. (c) With notes and sketches, show how the plate will be fixed to a wooden block. Expected responses include use of screws, contact adhesive, epoxy resin, use of brackets and making of rebate or groove to accommodate the sheet plates. Most candidates were able to give correct methods of attachment. Question 16 This question was based on the sketch of a corner bracket made from a 5mm thick plate. (a) (i) Name a metal which could be used to make the corner bracket; Expected responses include; mild steel, aluminum etc (ii) Using the metal identified in (a) use notes and sketches to show how the bracket could be made in the school workshop. Expected response involves marking out to given dimensions and locating centres for holes, drilling holes using the correct tool and use of correct method of holding work piece. Bending at an angle of 90 or joining method if made from two pieces.

9 Most candidates who attempted this question were not really clear with the stages in producing the bracket from a metal as a result they omitted some major stages of production. (b) (i) Name a manufacturing process which could be used to form plastic corner bracket. Expected response; injection moulding. This question confused candidates as most of them bend acrylic in strip heater.

1. List or sketch five entirely different forms in which METAL can be supplied to the school workshop.

Homework 1 - Metals 1&2 1. List or sketch five entirely different forms in which METAL can be supplied to the school workshop. 2. Metals are usually classified as Ferrous and Non-ferrous. Explain what