What Are Mechanical Assembly Drawings – Mechanical Drafting Course

There are several different types of assembly drawings. They are Outline or Setting Drawings, Erection Drawings, Assembly Working Drawings, Diagram Drawings, Part Assembly Drawings, and General Assembly Drawings.

1. The Outline Assembly shows the machines outline with no details. Center distances and over-all dimensions are given. An outline assembly drawing is used both for illustrations for a catalog and to show prospective customers an outline of the machine. In this case, only the general appearance of the machine is need.

2. Erection are those used in the erection of a machine. Each part is numbered and named so that it can be identified easily. These drawings give the exact location of each and every part and the proper order of the procedure in the erection of the machine.

3. The Assembly Working Drawing is used when only a few machines are going to be built. Each part is fully dimensioned therefore making it possible for the mechanic to build the machine from the assembly drawing instead of having to refer to various detail sheets. Using this method, a time is saved in the drafting room, since each detail does not have to be drawn individually.

4. A Diagram shows either a sectional or an external view of the entire machine. In this kind of an assembly drawing, all the parts are either numbered and named. A list of the parts is also included on the drawing.

5. A Part Assembly is the one that only a few parts of the machine are illustrated. In this instance, the parts should be shown relative to the entire machine and also to one another. An assembly drawing is made of the parts and each part is fully dimensioned so that greater detail is not needed in the part drawings.

6. General assembly are the illustrations used in designing a complete machine. When the design of a machine is undertaken in a drafting office, the drafter begins the process by making the preliminary sketches from the engineers notes and sketches and then creates a general assembly drawing. This general assembly drawing shows all the needed dimensions that limit the strength or working capacity of the machine and shows the general relation of the various parts to each other in the assembled machine.

This drawing is then turned over to another drafter who specializes in detailing or creating detail sheets where all the parts are drawn with all detail and dimensions.