392 Machine Drawing
dharm
d:\N-Design\Des20-1.pm5
20.2.2 Working Assembly Drawings
It is usually made for simple machines or jobs, consisting of a relatively smaller number of simple
parts. All the dimensions and information necessary for the manufacture of a part and for the
assembly of the parts are given directly on the assembly drawing. Separate views of specific parts,
in enlargement, showing the mating of parts, may also be drawn, in addition to the regular
assembly drawings. Figures 20.3 and 20.4 show the detailed assembly of a tea-poy and crank
assembly respectively.
Fig. 20.3 Detailed assembly drawing
20.2.3 Detailed Drawings and Manufacturing Methods
The type of manufacturing process influences the selection of material and detailed features of a
part (Fig. 20.5). As shown in Fig. 20.5a, if the component has to be cast, then rounds and fillets
are to be added to the part. Additional material will also be provided where surface requires
finishing.
Several drawings may be made for the same part, each one giving only the information
necessary for a particular stage in the manufacture of the part. A component which is to be
produced by forging, for example, may have one drawing showing the forged part (Fig. 20.5b) with
no machining details and a separate drawing for the machining of the forging (Fig. 20.6).
