Technical Design: 2010

Tuesday, May 18, 2010

Sectional Drawing

Part Drawings:

Detail drawings completely describe a single part with multiview orthographic projections
Should provide all the information necessary to economically manufacture a high quality part

Assembly Drawings:

Assembly drawings are used to the show the position and functional relationship of parts in an assembly, also via multiview orthographic projections
Generally they have no dimensions on them
Parts are 'balloon' identified and referenced to either detail drawings numbers or catalog numbers, via a Bill of Materials (BOM)

Section Views:

Section views are used to clarify internal detail and to avoid dimensioning to hidden lines
They are established by referencing a cutting plane
Cutting planes depict the exact location on the part from which the section view will be projected, and should have associated arrowheads, indicating the direction from which the section view will be observed
Cutting planes are constructed as an integral feature of the parent view, and cutting plane arrowheads always indicate the direction for the observer's line of sight

Crosshatching Section View:

Crosshatching is a repeating graphic pattern which is applied throughout all areas of the part that would be in contact with the cutting plane. Thus, the hole is not crosshatched
The recommended angle for the standard crosshatch pattern is 45, 30, or 60 degrees with horizontal. Similarly, crosshatch lines should be neither parallel nor perpendicular to the outline of the feature in section- if avoidable

Half Section:

Half section views are the result of cutting planes being positioned on parts in such a manner that only half of the resulting view or projection is shown in section
Half sections are generally used on objects of symmetry, individual cylindrical parts, or assemblies of parts

Offset Section:

Offset sections allow us to provide greater breadth of detail with fewer section views. All of the features are aligned with the cutting plane

Coordinate Dimensioning and Tolerancing:

The collective process of modeling, defining, and describing geometric sizes and feature relationships, and providing all of the required technical information necessary to produce and inspect the part is called dimensioning and tolerancing

Thursday, April 15, 2010

The forklift gets its name from the two forks that protrude from the front of the machine. These forks can be maneuvered not only by being raised and lowered vertically, but also by tilting downward and upward. These movements are accomplished with a hydraulic cylinder used to apply pressure against a bar equipped with roller chains. The roller chain is attached to a frame at one end and the forks at the other.