FIGURE 11.1 below shows an off-centre rectangular to rectangular hopper - NSC Mechanical Technology Welding and Metalwork - Question 11 - 2019 - Paper 1

The true length AE is determined using the formula:

$AE = \sqrt{IE^2 + AI^2 + VH^2}$

1. From the figure, we have:

   • IE = 150 mm
   • AI = 350 mm
   • VH = 450 mm

2. Plugging in the values to compute AE:

   $AE = \sqrt{150^2 + 350^2 + 450^2}$

   Calculating:

   $AE \approx 590 \text{ mm}$

To find the plan length MK, use the formula:

$MK = LK - LM$

1. Identify lengths:

   • LK = 350 mm
   • LM = 200 mm

2. Therefore,

   $MK = 350 - 200 = 150 ext{ mm}$

To find the true length DH we utilize:

$DH = \sqrt{HK^2 + KD^2 + VH^2}$

1. From the figure:

   • HK = 150 mm
   • KD = 300 mm
   • VH = 450 mm

2. Thus,

   $DH = \sqrt{150^2 + 300^2 + 450^2}$

   Which approximates to:

   $DH \approx 498 \text{ mm}$

To draw the pattern for plate A:

1. Start with a rectangular shape with dimensions:
   • Base width: 900 mm
   • Top width: 400 mm
   • Height: 590 mm
2. Draw trapezoidal lines connecting the top corners of the rectangular shape to represent the hopper.
3. Ensure to include necessary dimensions for clarity.

For drawing the pattern for plate C:

1. Begin with a rectangular shape with dimensions:
   • Base width: 600 mm
   • Top width: 300 mm
   • Height: 498 mm
2. Similar to plate A, ensure to connect the top corners with trapezoidal lines.
3. Clearly mark the dimensions for reference.