Auxiliary Views Information

AUXILIARY VIEWS & TERMINOLOGY

The Isometric Views shown below are of a Single Object from Four Directions. Study the Views carefully and then move to the bottom of this page to see a Multiview Drawing that includes Auxiliary Views.

SURFACES

NORMAL SURFACES are either vertical or horizontal planes that are parallel to the the six principal planes of projection or normal views.

INCLINED SURFACES are sloping upward or downward at some angle to the horizontal plane of projection or top view.

ANGLED SURFACES are vertical surfaces that are at some angle to the front, back or side views.

OBLIQUE SURFACES are at some angle to ALL sides of the object.

STUDY GUIDE - AUXILIARY VIEWS

Auxiliary views are supplemental views added to a multiview drawing that contains the normal top, front and right-side views of an object.
Auxiliary views are used to find the true length and point views of an oblique line; and to find the edge and true shape views of inclined, angled or oblique surfaces.
Oblique lines appear to be going upward or downward from the left to the right in the front, rightside and front views.
Angled surfaces appear as a shape in the frontal and profile views and as a line in the horizontal view. Angled surfaces are always perpendicular to the horizontal plane.
Inclined surfaces appear as a shape in the horizontal and frontal views and as a line in the profile view or as a shape in the horizontal and profile views and as a line in the frontal view. Inclined surfaces are always perpendicular to either the frontal or profile planes.
Oblique surfaces appear as a shape in the horizontal, frontal and profile views. Oblique surfaces are are not perpendicular to the horizontal, frontal and profile planes.
Auxiliary views can be classified as primary or secondary; and as an inclined or an elevation auxiliary view.
The primary auxiliary view can be projected from any of the normal (top, front or rightside) views.
The secondary auxiliary view can be projected ONLY from a primary auxiliary view.
The auxiliary inclined view can be projected from a front or a side view with a line of sight at some angle to the ground or horizon.
The auxiliary elevation view can be projected ONLY from a top view with a line of sight at some angle to the the front or side of the object and parallel to the ground or horizon.
Auxiliary views are created by adding a "line of sight" (LOS), a "reference line" and "projection lines".
The "LOS" represents the direction you are looking at an object. The "line of sight" must be perpendicular (90°) to any view of a line to find the "true length" (TL) of the line. The "line of sight" must be perpendicular (90°) to the "edge view of a surface" to find the "true shape" (TS) of the surface.
A "reference line" represents the intersection of two imaginary "projection planes" (Horizontal/Frontal) (Frontal/Profile) (Horizontal/Auxiliary Elevation) (Frontal/Auxiliary Inclined) and is used to measure distances from the planes to points on an object. "Reference Lines" are drawn as a "phanton lines" (long, short, short, long) and at 90° angles to the "LOS".
A "projection line" shows the relationship of two views of a point. "Projection Lines" are drawn as "dashed lines" and at 90° angles to "reference lines".
"Revolution" is an alternate method for finding "true lengths" and "true shapes". An "end point" of an "oblique line" can be rotate about a vertical or horizontal axis until the "oblique line" is parallel to a "reference line". The "rotated end point of the line" can be projected into the adjacent view and lined up with the original position of the "end point of the line". A new image of the rotated line can be drawn in the adjacent view and the "true length" measured. This method reduces the potential for errors when transferring measurements and requires less space on the drawing sheet.