Page 224 - Engineering drawing from first principles using AutoCAD

Technical drawinqs for industry 217

Figure 10.6 shows the front and plan view of a cast anchor bracket in first angle projec-
tion. We are required to draw the given front view and project in first or third angle
projection the following views:

• a plan view taken as a section on the cutting plane AA;
• a sectional end view on the cutting plane BB.
This example is a typical casting where a central boss is supported by four webs. Other
details include two counterbored holes in the base, two slots and four chamfered
corners at 45°. At the right-hand side of the boss there is a tapped hole. The example
is also given to show how these details are dimensioned and section planes are
indicated.

Copy this drawing and accurately position all fillet radii. Save your drawing under a
different drawing number and then convert it into the given solution including sec-
tions A-A and B-B. Note that the cutting plane for section B-B incorporates the BS
308 convention relating to thin webs, which are not cross-hatched. In Fig. 10.7 the
solution is given in first angle projection. Fig. 10.8 shows a third angle projection
solution, assuming that the same vertical section plane is used but that the arrows
point in the opposite direction to show an alternative end view. There are three points
to remember:

• the section plane indicates the position where the component is cut;
• the arrows point to the part of the component to be drawn;
• the projection angle dictates where the drawing will be positioned on the solution.

a~ stdO'~ O. d~f
(~~std ~~4~~.d~f
a~..,td~~4"1.(,bd
a~std ~~~~O.d:sd

--l1I
1...---

Figure 10.18