21. True or false? All answers will be found in the text or in the figures in Chapter 3.
■ The ISO type A' and 'B' line thicknesses should be in the proportion 1:2.
■ The line types 'C' and 'D' are interchangeable.
■ Cross hatch lines are at 45° wherever possible.
■ Sections are always cross hatched, irrespective of the size or length of the section.
■ It is not necessary to have a terminator at the end of a leader line.
■ Dimension projection lines do not always have to be type 'B' lines.
■ The ISO recommended decimal marker is a comma.
■ The Greek letter '<)>' must always be used to indicate diameter.
■ Flat surfaces such as squares, tapered squares can be represented in their side view by a'+' sign.
■ When drawing splines or gears, each and every tooth needs to be included in the drawing.
■ Colour is not recommended in engineering drawings.
22. Using your intuition, guesstimate the ranking of the 10 ISO line types in Figure 3.4 according to the frequency of their use in engineering drawings in general. To help you, I think type 'A' is used the most because it is the principal line for part outlines and shapes. I think type 'B' is a very close second because it is used for cross-hatching and dimensions. What do you think about my thoughts and about the other line types? Would you expect the ranking to be different for detailed drawings as opposed to assembly drawings? (Section 3.2.)
23. With respect to the movable jaw drawing in Figure 3.2, count the number of lines in each of the 10 ISO line type classes. Work out the percentages of each and from this, rank the 10 according to their frequency of use. Compare your answer with your guesstimate. (Section 3.2.)
24. With respect to the assembly drawing in Figure 3.1, count the number of lines on the drawing in each of the 10 ISO line type classes. Work out the percentages of each and hence determine the ranking of the frequency of use. Compare this answer with your guesstimate. (Section 3.2.)
25. Draw a section through a threaded bolt located in a threaded hole. The male threaded bolt should not be sectioned but the hole should be. The reason for this question is to ensure you understand the use of the line types A and B for male and female thread forms. (Section 3.8.3 and Figures 3.5 and 3.6.)
26. Using your template from Question 4, redraw the vice assembly drawing in Figure 3.1 in third angle projection but include the following views:
■ a full sectional front view (rather than the partial front view shown);
Include hidden detail as appropriate. Add a balloon reference system. Add an item list.
27. Using your template from Question 4, redraw Figure 3.3 of the hardened insert in third angle projection but without the dependency on the symmetry as given by the 'equals' sign. Add dimensions sufficient for it to be made. This could involve adding dimensions from the sides. Beware of the error of repeating dimensions. Include at least one auxiliary dimension.
28. Figure 2.16 shows the drawing of a flange. Assume the outside diameter is 150mm. Reproduce the two drawings as shown in third angle projection and, using scaling measurements, add dimensions sufficient for the flange to be manufactured. Use your template from Question 4.
29. Using your drawing template from Question 4, redraw in third angle projection the movable jaw in Figure 3.2 but draw the following three views:
■ the left-hand side view section through the centre;
■ a right-hand side section through one of the <|>5/<|>8 counter-bored holes.
Fully dimension the jaw sufficient for it to be manufactured and include hidden detail if you think it helps understanding. Add the title information.
30. With reference to Figure Q30, draw the nut, bolt and washer assembly full size for M20 as well as separate detail drawings of the nut, bolt and washer. Use third angle projection. The bolt length should be 60mm and the thread length 40mm. Dimension the detail drawings. Use your drawing template from Question 4.
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