Questions: 13 Pages: 12 ©Copyright for part(s) of this examination may be held by individuals and/or organisations other than the Tasmanian Qualifications Authority.

Tasmanian Certificate of Education

DESIGN GRAPHICS

Senior Secondary 5C

Subject Code: TE836

External Assessment

2007

Time: Three Hours

On the basis of your performance in this examination, the examiners will provide results on each of the following criteria taken from the syllabus statement: Criterion 4 Develop skills in interpreting and transferring drawings. Criterion 5 Solve problems. T

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CANDIDATE INSTRUCTIONS You MUST ensure that you have addressed ALL of the externally assessed criteria on this examination paper. You must answer SEVEN questions in total: ALL FOUR questions from Section A ONE question from each of Sections B, C and D You should spend approximately 60 minutes on Section A and approximately 40 minutes on each of the other three questions. You are required to use correct linework and presentation, and are encouraged to include freehand sketches, where necessary, to show the development of ideas in the solution of problems. Construction must be shown. All written responses must be in English.

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SECTION A

Answer ALL questions in this section. Question 1 – This question assesses Criterion 4. Construct a regular pentagon in an 84mm dia circle. Use the pentagon to draw three elevations of a 55mm high pentagonal prism in Third Angle Orthographic projection. Question 2 – This question assesses Criterion 5. Draw the largest possible tetrahedron (equilateral triangular pyramid) that will fit into a 60mm diameter sphere. Question 3 – This question assesses Criteria 4 and 5. Draw an isometric view of an ellipse with a 75mm major axis and 40mm minor axis. Question 4 – This question assesses Criteria 4 and 5. Freehand draw and dimension a mechanism that will cause the hammerhead in Figure 1 to move up and down through a vertical height of 35mm while the handle of the hammer is free to rotate around the pivot at P. Name the type of motion imparted to the hammer by the mechanism.

Figure 1

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SECTION B

Answer ONE question from this section. This section assesses Criteria 4 and 5 weighted 1:4 respectively. Question 5 One method of connecting a vertical sheet of plywood to a horizontal sheet is to use a glue fillet. This is done by filling the corner at the join with glue then dragging a circular disc held at right angles to the join line along the corner to produce a quarter round fillet of glue, as shown in Figure 2. The excess glue is removed after the operation. Construct the shape of the glue fillet if the disc is inclined in the direction of the arrow at 45˚ to the join.

Figure 2

Section B continues opposite.

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Section B (continued) Question 6 A round reflector R is fitted to a bicycle wheel as shown in Figure 3. Show the path of the reflector R as the wheel rolls for one full revolution.

Figure 3 Section B continues over the page.

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Section B (continued) Question 7 Draw a plan and two elevations of the symmetrical 25mm side pentagonal dodecahedron shown as a three dimensional view in Figure 4. Note: Opposite pentagonal faces are parallel.

Figure 4

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Not drawn to scale

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SECTION C

Answer ONE question from this section. This section assesses Criteria 4 and 5 weighted 4:1 respectively. Question 8 Figure 5 shows the simplified side view of a clown’s bicycle with an off-centre back wheel axle. Draw the path of the seat centre S for one full rotation of the back wheel as the bike moves from left to right.

Figure 5

Section C continues over the page.

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Section C (continued) Question 9 Develop all the surfaces of the quarter-sphere ladle (excluding the handle) shown in Figure 6.

Figure 6 Question 10 Draw an isometric view of the ladle shown in Figure 6.

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SECTION D

Answer ONE question from this section. This section assesses Criteria 4 and 5 weighted equally. Question 11 Figure 7 shows a simplified rack onto which engages a pinion. The pinion requires a helical thread, as shown by the thread profile A, on the shaft to engage the teeth of the rack and move the rack to the left or right as the thread is rotated anticlockwise or clockwise respectively. The thread is to be cut within the WXYZ rectangle. Construct two turns of the required thread.

Figure 7 Section D continues over the page.

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Section D (continued) Question 12 Figure 8 shows the plan and elevations of a bedroom. Included is a viewing (eye) position (E. P.) with four closed Venetian slats covering the window. Construct a view of the blind as seen from the Eye Position (E. P.).

Question 13 If the slats in Figure 8 are at rotated 45o to the glass, show graphically whether the greatest view from the eye position is possible from the top or bottom of the window.

Figure 8

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