5.2 Orthogonal drawing

An orthogonal drawing , which is also known as the “parallel projection method,” is an image of an object, some of which are projected in parallel onto two (or three) mutually perpendicular planes. This is the most accurate and rational method of depicting an object on a plane, on which the entire system of modern projection drawing is based. An orthogonal drawing is the most common form of communicating information about a projected object, which allows not only reliably transmitting in the image the geometric parameters of the form, but also, by means of large-scale transformations, correlate its image with the true dimensions of the object.

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For the main projection planes, there are six sides of the cube, onto which any object can be projected. The combination of these faces with the frontal plane provides a certain mutual position of the six projections of the depicted object. Depending on the content of the image are divided into types, sections, sections.

A view is an image of the visible part of the object surface facing the observer. Section is a part (object), mentally dissected by one or several conditional cutting planes. A cross section is a figure obtained as a result of dissecting an array of a part by a secant plane.

In the performance of orthogonal drawings should:

- execute the drawing in accordance with the mandatory orientation of the drawing projections relative to the vertical and horizontal axes;

- arrange drawing projections in such a way that between them there is a projection relationship;

- consider the composition of the drawing to be the subject of special attention, for which it is necessary to carefully weigh the compositional interrelation of drawing projections, inscriptions, dimensions, scale lines, etc.

If there is no accurate, detailed linear pencil drawing with the image of axes, dimension and scale lines, digital and font lettering, then there can be no high-quality touch stroke of the drawing, good execution of the wash-off or color graphics.