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ENGINEERING, AE 2025 HSC 19 MC

The orthographic views of a part are shown.
 

What is the total number of true lengths that are visible in ALL three views?

  1. 9
  2. 10
  3. 12
  4. 15
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\(B\)

Show Worked Solution
  • A true length appears when a line is parallel to the projection plane — it shows its actual length in that view.
  • Top view: the base rectangle has 4 true length edges; the base diagonal is also a true length = 5 true lengths.
  • Front view: the base line is true length; one slant edge is true length = 2 true lengths.
  • Side view: the base line is true length; both slant edges are true length = 3 true lengths.
  • Total: \(5+2+3=10\)

\(\Rightarrow B\)


♦♦♦ Mean mark 30%.

ENGINEERING, AE 2017 HSC 26b

Orthogonal and pictorial drawings of a sheet metal electrical cable cover are given below.
 

  1. Draw a half-development of the electrical cable cover. Use the centre line to position the development.   (4 marks)
     

  1. A 20 mm diameter hole is to be punched through the top of the electrical cable cover before folding.
  2. The ultimate shear stress of the material used to manufacture the cover is 110 MPa.
  3. Calculate the force required to punch out the hole if the thickness of the sheet metal is 0.5 mm.   (3 marks)
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i.   
         

ii.   `3.46\ text{kN}`

Show Worked Solution

i.   
         

Key Points for this Drawing:

  • Find true length of each line from the diagrams given
  • Do not dimension
  • Only complete a half development, not a full development
  • Use lighter lines for the the bends/folds and heavier lines for the outline
  • Label all points
ii.    `delta_S` `=F_S/A_S`
  `F_S` `=delta_S xx A_S`

 
`A_S = pid xx t=pi xx 20 xx 0.5 = 31.4\ text{mm}^2`

`:.F_S= 110 xx 31.4=3455.7\ text{N}=3.46\ text{kN}`


♦ Mean mark (ii) 42%.

ENGINEERING, AE 2022 HSC 27b

The top and front views of a transition piece in an aircraft air conditioning duct are shown.

Complete a half-pattern development of the transition piece, starting from the line `a`-1 given below.   (6 marks)
 

     

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Notes on this drawing:

  • Ensure you find the true length of lines
  • Ensure fold lines are lighter than the outline
  • Since the half development cuts through a side, ensure you use a break line
  • Do not dimension
  • Only complete a half development and not a full development
Show Worked Solution

 

Notes on this drawing:

  • Ensure you find the true length of lines
  • Ensure fold lines are lighter than the outline
  • Since the half development cuts through a side, ensure you use a break line
  • Do not dimension
  • Only complete a half development and not a full development

♦ Mean mark 40%.

ENGINEERING, AE 2018 HSC 12 MC

A transition piece is shown.
 

Which of the following correctly represents the development of the transition piece?
 

 

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`A`

Show Worked Solution
  • As shown in the diagram, the longer ends of W, X, Y and Z are all at the same end of the piece.
  • A is the only answer which suits this criteria.

`=>A`

ENGINEERING, AE 2022 HSC 8 MC

It is appropriate to produce a half development of a transition piece when the piece

  1. is very large.
  2. is symmetrical.
  3. is very complex.
  4. needs to be produced quickly.
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`B`

Show Worked Solution
  • Half development of a transition piece is appropriate when it is symmetrical.

`=>B`