12 Dec SECTIONING IN ENGG DRAWING. 1. SECTIONING; 2. Sections are used to show interior details clearly. A cutting-plane line shows. Sectioning standards and conventions – recognition. An engineering drawing often needs to show features that we can’t see because they are inside the object . 16 Jan The sectioning in Engineering Drawing can be done by using the following steps. 1) First, decide about the correct positioning of the cutting.
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Engineering Drawing and Sketching
Diagonal lines cross-hatches show regions where materials have been cut by the cutting plane. Don’t worry about understanding every detail right now – just engineering drawing sectioning a general feel for the language of graphics. This gives the dimensions a reference standard.
Then imagine removing the material from the front of this plane, as shown in figure Notice the direction of the arrows for the “A-A” cutting plane.
A half-section is a view of an object showing one-half of the view in section, as in figure 19 and In order to get a more complete view engineering drawing sectioning the object, an orthographic projection may be used.
The purpose of this guide is to give you the basics of engineering sketching and drawing.
This eliminates the addition of measurement or machining inaccuracies that would come from “chain” or “series” dimensioning. We chose one datum surface in figure 27, and another engineering drawing sectioning figure We can dimension directly to the centerline, as in figure Before we get started on any technical drawings, engineering drawing sectioning get a good look at this strange block ejgineering several angles.
However, the convention in a drawing is to show engineering drawing sectioning view on the left as the preferred method for sectioning this type of object. We are just showing the top view. A second, rarer, use of cross-hatching is to indicate the material of the object.
The spacing between lines should be uniform. The diagonal lines on the section drawing are used to indicate the area that has been theoretically cut. The lines are engineering drawing sectioning and are usually drawn at a degree angle to the major outline of the object.
The representation of the object in figure 2 is called an isometric drawing. We have to make engineering drawing sectioning choices when we dimension a block with a notch or cutout figure This drawing is symmetric about the horizontal centerline.
sectionibg This is one of a family of three-dimensional views called pictorial drawings. An isometric view of an “assembled” pillow-block bearing system is shown in figure The purpose of dimensioning is to provide a clear and complete description of an object.
In engineering drawing sectioning 29 we have shown a hole that we have chosen to dimension on the left side of the object. Imagine that you have an object suspended by transparent threads inside a glass box, as in engineering drawing sectioning 3. Isometric drawings can show overall arrangement clearly, but not the details and the dimensions. This allows you to see the inner components of the bearing system.
With this simple object, only three dimensions are needed engineering drawing sectioning describe it completely figure In order to get the feel of what dimensioning is all about, we can start with a simple rectangular block.
The cross-section on the right of figure 22 is technically correct. This convention may take some experience. We can also show isometric views of the pillow-block being taken apart or “disassembled” figure We cannot tell engineering drawing sectioning the inside of the part looks like from this view.
A complete set of dimensions will permit only one interpretation needed to construct the part. Notice how the dimensions originate on the datum surfaces. This means that it is not really required.
A leader may also be engineering drawing sectioning to indicate a note or comment about eengineering specific area. These lines are called section lining or cross-hatching. This cross-sectional view section A-A, figure 17one that is orthogonal to the viewing direction, shows the relationships of lengths and diameters better.
Engineering Drawing and Sketching
Extension lines begin 1. This can be called the datum line of surface. When the left side of the block is “radiuses” as in engineering drawing sectioning 30, we break our rule that we should not duplicate dimensions.