Free Hand Sketching

Freehand Sketching
Sketching is an important method for quickly and economically communicating your design ideas. Visualizing objects in three dimensions is aided by sketching.

Sketching is a process of creating a rough, preliminary drawing to represent the main features of a design, whether it is a manufactured product, a chemical process, or a structure. Commonly, sketches are produced freehand, with a minimum of instrument use. The tools used for sketching consist of pencil, eraser and paper. Software-based systems (e.g. AutoCAD®) may also be used, but paper and pencil are far more transportable, less costly, and are often close at hand.

Sketches take many forms, and vary in level of detail. The engineer determines the level of detail based on clarity and purpose of the sketch, as well as the intended audience. Sketches are important to record the fleeting thoughts associated with idea generation. Clarifying a technical detail can be aided through sketching. Explaining a complicated manufacturing or chemical conversion process can be visualized through use of a well-developed sketch.

Sketching is an important tool for communicating with other members of the design team and is most commonly used in the idea generation stage of the project. Sketching is often used to explore ideas, capturing mental images that result from the creative thinking process. Sketches are typically less detailed than design drawings, so the engineer is free to rapidly produce and capture ideas in a less restrictive form.

A freehand sketch is not a messy drawing, nor should a messy drawing be considered a freehand sketch. There are rules that apply to freehand sketching, just as rules apply to every other form of communication. Why? Recall the objectives for producing a freehand sketch in the first place (rapid, preliminary drawings to convey the main features of your design to other people). Secondly, recall that if you are investing the resources (your time, money, and your supervisor’s time) in recording a design idea, then it is best done correctly, the first time.

Sketching Tools

Pencils
Use of a medium hardness pencil lead (e.g., H, HB) is often best for sketching. Mechanical pencils retain a point better than wooden pencils, allowing greater control over the quality of the lines being drawn. If only a single pencil is used, a 0.5-mm lead thickness is the optimum choice. Thicker lines may be drawn with a 0.7-mm lead mechanical pencil, if emphasis is desired.

Eraser
Use an eraser only to correct a mistake in drawing. If you want to change the design, make a new sketch.

Paper
One might use plain bond paper for the greatest degree of flexibility. Square grid and isometric grid paper is helpful for drawing straight lines and keeping the dimensions in proportion to each other. Tracing paper placed over grid paper allows one to produce a freehand sketch without contending with visible lines in the final sketch.

posted by:gloria and nissan