1.) Why are drawings composed of different line conventions?
Drawings are composed of different line conventions because they need to represent the object. So, the different line conventions help identify how the object looks. A hidden line shows what is behind the current view, object lines show what the object is. short break lines show detail or shorten a long part, and there are many more line conventions. They're all used so that drawings can show every part of the object (necessary) and accurately.
2.) What is the purpose of a sectional view?
The purpose of a sectional view is to show the internal structure of an object that can't be viewed from any of the main orthographic views.
3.) What is the purpose of an auxiliary view?
The purpose of an auxiliary view is to show the true size and shape of a feature on the object. It is often used to show features that are on a sloped edge and that are not viewed correctly in the main orthographic views.
4.) Why are symbols used instead of words to identify hole types?
Symbols are used instead of words to identify hole types, because they represent how the actual holes look. For example, the symbol for countersink holes shows how it ends with a point. The counterbore shows how the hole is flat-bottomed. The symbols are also useful because they are shorter and take up less space than writing "countersink" or "counterbore" to describe the holes.
5.) What advantages do CAD drawings have over paper sketches?
The advantages CAD drawings have over paper sketches include being more exact. The drawings in CAD make views directly from the object, so there will be no errors in how the views look, and no hidden lines will be missed. It is also easier, because if section views, detail views, or auxiliary views are made, you don't have to worry about visualizing and getting the view exactly right yourself. It takes much less time because of this, because the views are easy and quick to make. They'll also be more neat and organized to look at, because paper sketches are often messier.