7 Auxiliary Views

  • FRONT VIEW AUXILIARIES
  • TOP VIEW AUXILIARIES
  • SIDE VIEW AUXILIARIES
  • SKETCHING AUXILIARY VIEWS

When an object has a slanted or inclined surface, it usually is not possible to show the inclined surface in an orthographic drawing without distortion. To present a more accurate description of any inclined surface, an additional view, known as an auxiliary view, is usually required.

An auxiliary view is simply a “helper” view, which shows the slanted part of the object as it actually is. It turns, or projects, the. object so that the true size and shape of the surf ace (or surfaces) are seen as they actually are.

Auxiliary views are commonly found on many types of industrial drawings.

Front View Auxiliaries

There are three basic type of auxiliary views. In the first type, the auxiliary view is projected from the front view of a three view (orthographic) drawing. In the second and third types of drawings, the auxiliary views are projected from the top and side views.

Here is a front view auxiliary of a simple object with an inclined surface.

 

Graphic showing an auxiliary view. The image features a geometric drawing with five outlined shapes in a technical style. In the top right, there is a three-dimensional block with an inclined surface, labeled with the text "INCLINED SURFACE." This block appears trapezoidal from the top. Below it, on the left side, is a rectangular shape divided into two sections. In the center, a slightly rotated square shape is linked to another shape below it. The bottom shape resembles a parallelogram with another inclined surface on the upper side, also labeled "INCLINED SURFACE." Finally, in the bottom right corner, a simple rectangle is divided into two parts, creating a visual symmetry with the rectangular shape at the top left.

 

Notice that the projection lines are perpendicular to the slanted surface of the first view, and that only the slanted surface of the object is shown in the auxiliary view. · The rest of the object is omitted, however, for clarification portions of the adjacent· surfaces are sometimes shown. Also, notice that the slanted surfaces of the top and side views are shortened because of distortion, whereas the surface of the auxiliary view is true, or actual size.

To sketch an auxiliary view, you begin with orthographic. views of the object and add projection lines perpendicular (90◦) to the slanted surface, adding a reference line any convenient distance from the view with the slanted surface.

 

Auxiliary view explanation. The image consists of several geometric diagrams, each featuring rectangular shapes. In the upper left, there is a horizontal rectangle divided into two sections, labeled as A and B, with a reference line pointing above it. In the middle, a tilted rectangle is shown with lines extending outward, also labeled A and B, and labeled with a reference line. Below, there is a rectangle with one corner cut at an angle. Finally, on the lower right, there is a small square containing two sections.

 

Next, the distance CB on the auxiliary view is made the same length as the related distance in one of the orthographic views; in this example it’s the side view. This completes the auxiliary view.

 

Auxiliary view layout explained. The image consists of four geometric shapes labeled with points A, B, C, and D. The top left shape is a large rectangle with segments labeled on the top as A and B, and the right segment labeled as C and D. Below it is a trapezoid with the top labeled D, A and the bottom labeled C, B. The top right shape is a square rotated 45 degrees with vertices labeled A, B, C, and D. The bottom right shape is a vertical rectangle divided into two parts, horizontally, with labels A, B on the top and C, D on the bottom.

Top View Auxiliaries

A top view auxiliary is developed in the same way as a front view auxiliary, except that the auxiliary is projected from the top view.

Whether the auxiliary view is to be projected from the front, top, or side view depends on the position of the object, or which surface of the object is slanted. In this example, the top view is slanted. Therefore the auxiliary view must be projected from the top view.

Again, notice how the angled surfaces shown in the front and side views are not shown in true length.

 

Top Auxiliary view drawing process. The image displays a technical drawing with multiple views of a rectangular object and its auxiliary view. The top section shows a slanted rectangle alongside a rotated square labeled "Auxiliary View." The rectangle is aligned diagonally, connected to the square by lines, with corners labeled C, B, D, and A. The square has its own labeled corners, A to D, matching the rectangle's labels. Below, two rectangular projections are shown. The bottom left is a wide rectangle split into two sections, marked D, C on the left and A, B on the right. The bottom right is a smaller rectangle also divided into two sections with the same labels: D, C on the left and A, B on the right.

Side View Auxiliary

Side view auxiliaries are drawn in the same way as front and top view auxiliaries. Again, where the auxiliary view is to be projected depends upon the position of the object or which surface of the object is slanted.

 

Side view auxiliary view explained. The image consists of three simple geometric diagrams, each displaying a rectangle labeled with points A, B, C, and D. Starting from the top-left, the first diagram is a horizontal rectangle divided by a horizontal line, creating two sections; the labels are on the corners as follows: top-left C, top-right B, bottom-left D, and bottom-right A. At the bottom-left, a similar rectangle is oriented horizontally with points labeled: top-left C, top-right B, bottom-left D, and bottom-right A. The third figure on the right is a composite of two geometric shapes: a large tilted rectangle and a smaller, adjoining right triangle, with shared lines between points A and D. The rectangle is labeled with A at the bottom-right, B at the top-right, C at the top-left, and D at the bottom-left. The smaller triangle shares points A and D with the rectangle.

Obviously, these are very basic auxiliary view examples and are presented to introduce you to the concept of auxiliary views.

As objects with inclined surfaces become more complex, auxiliary views provide a means of presenting objects in their true size and shape.

Sketching Auxiliary Views

The following problems require and auxiliary view to be complete. Sketch the auxiliary views required in the spaces provided.

 

Drawing practice 1

3 orthographic views provided, draw the auxiliary view. The image consists of three geometrical shapes arranged on a white background. At the top left, there is a rectangle with a vertical line on its left side, appearing like a side view. Below it, a quadrilateral with one sloped side is positioned, resembling a right triangle attached to a rectangle, indicating a base with an angled side. On the right side near the bottom, a square with a horizontal line at the bottom sits, resembling another side view. An arrow labeled "AUXILIARY VIEW" points towards the center of the image from the top right.

Drawing practice 2

In this problem, a round hole is centered on the slanted surface and drilled through the object. The hole appears elliptical in the. front and side views because of distortion. It will appear in its true shape on the auxiliary view. Remember that the auxiliary is developed from the view with the slanted surface. Complete the auxiliary view.

 

Auxiliary drawing practice 2, orthographic views provided. The image consists of three separate diagrams, each outlined in black against a white background. In the top-left corner, a larger geometric shape is depicted. It starts as a rectangle on the left and transitions into a wedge with angled lines extending rightward, indicating depth or a cutout. The shape includes three diagonal dashed lines running parallel from the top left to the bottom right. At the bottom left, a rectangle is divided into two sections. The left section contains a circular shape with a dashed boundary and crosshairs in the center, possibly indicating a projection or alignment. The right section holds an ellipse with solid lines and its own set of crosshairs. To the bottom right, another smaller rectangle features an ellipse with crosshairs and a dashed line across it, implying sectioning or projection details.

Drawing practice 3

In this problem, a square hole has been cut part way into the object. Complete the auxiliary view.

 

Auxiliary view practice with 3 orthographic views provided. The image consists of three geometric drawings, each showing a rectangular solid with different views. The top view features a large rectangle containing a smaller, centered rectangle and a dashed line indicating hidden edges. There is a horizontal line near the top edge. The middle view, a front elevation, displays the same rectangle with a smaller rectangle centered within and a horizontal dashed line below the smaller rectangle. The bottom right shows the right-side view, which appears as a trapezoid with a slanted top line. A dashed outline of a rectangle is visible inside the trapezoid.

Quiz

Directions: Complete the auxiliary view in the space provided.

 

Auxiliary view practice, 3 orthographic view provided. The image displays three technical drawings of mechanical parts on a plain background. In the top left, there is a rectangular section with a circular detail, indicating a possible bore or hole with concentric dashed lines. The bottom left features an angular formation resembling a right triangle with reinforcing lines. The bottom right shows a vertical tab-like shape with a rounded top, incorporating a central circular marking. Each drawing is characterized by precise, black line work including solid and dashed lines, suggesting dimensions and hidden features.

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