No supplementary references are needed for this task. 1. Introduction
In the previous four tasks, we covered a great deal of information concerning drafting, shop drawings and blueprints.
As a repair shop technician, you will be required, from time to time, to interpret shop drawings and blueprints, not only to enable you to explain and teach lower ranking personnel, but also to enable you to brief higher authority on the status of work within the shop. In this task, we are going to cover production drawings and interpret a shop drawing.
Production drawings are used to aid a craftsman in the manufacturing of an object. They are generally either detail drawings or assembly drawings. A detail drawing usually presents only one object. An assembly drawing presents several objects together.
It is sometimes difficult to realize that the picture portion of a drawing is only one part of the total finished drawing. The title block, revision block, and drawing notes are just as important as the picture portion, and often they are just as time-consuming to prepare.
a. Assembly Drawings. Assembly drawings show several objects joined together. An assembly drawing must include all information needed by the craftsman to correctly assemble the parts. They do not usually include specific object dimensions which are necessary for assembly.
Figure 88 (on the following page) illustrates an assembly drawing. Each object is identified by part number, but it is not dimensioned. Hidden lines have been omitted to make the drawing easier to read. This is not always possible, especially for assemblies that contain internal parts.
If any specific operation is to be performed by the assembler, it must be noted on the assembly drawing. For example, if several parts are to be joined together by a bolt, the bolt hole should, if possible, be drilled during the parts assembly to ensure that all the parts align properly.
Assembly drawings sometimes reassign new part numbers to the various component pieces that make up the assembly. Assembly numbers are usually one or two digit numbers (1, 2, 3, 14, 22, etc.) and are added to save printing the larger, more complicated part numbers on the assembly drawing. If assembly numbers are used, include them in a column in the parts lis t next to and to the l eft of the part numbers.
b. Detail Drawings. Detail drawings are used by the craftsman to produce a finished object. They are a set of instructions that should include all information necessary for the complete and accurate manufacture of the object. They should include, among other things, a complete size and shape definition of the object; the material from which the object is to be made; all necessary information on the treatment of the materials; surface finish requirements; references to applicable specifications; any necessary inspection information; and, if necessary, instructions for handling the finished object. Figure 89 (on page 102) illustrates a detail drawing.
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