Engineering Drawing

Sketching SkillsGSMST

Objectives

Tips and TechniquesLetteringPatience and practice needed

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Sketching

Although most final drawings are computer generated, initial and freehand sketches are vital to the design processFreehand does not mean messy. Sketches should display an adequate amount of detail, and any pertinent notes/comments pertaining to the drawing For instance, if a line is supposed to be

straight, make it as straight as possible. A square will not pass for a circle.

Sketching

Sketching is a rapid, freehand method of drawing without the use of drawing instruments. Sketching is also a thinking process and a method of communication.

SketchingThis is not artistic sketching, but technical sketchingEmphasis will be on sketching geometric figures to represent features of objectsMedium grade pencils work best for sketchingAll lines should be dark enough to standout from the page

Engineering Drawing RulesAlways use a Pencil.Make all lettering the same size.Use Engineering or Drafting Paper.

Pencil Techniques

The best pencil for lettering on most surfaces are the H, F, and HB grades.Hold your pencil in the position shown. It should make approximately a 60o angle with the paper.

Pencil Lead Designation

Note: Reverse order below

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Sketching Tips: GeneralRelax and draw in a direction comfortable to youMark end points of the lines to be sketched and draw between themDraw long lines as a series of short onesUse grid paper when availableFollow sketching and text conventionsDo NOT use a straight edge to draw lines!

Sketching Tips

Sketching straignt lines does not mean they have to look like they are machine drawn.

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Sketching Tips: Construction Lines

Use construction linesBegin by drawing bounding boxes with construction linesMake construction lines much lighter and thinner than finished linesIdentify the major features and overall dimensionsLeave construction lines on the sketch

Drawing Circles

Two methods for sketching circlesBox in diameter and mark radiusDraw center-point lines and mark radius

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Sketching Tips: Miscellaneous

Do not shade the drawing – this is not pencil sketchingTitle information is requiredKeep views aligned (very important)Draw neat circles – change page orientation if needed

Sketching techniques

Use very light construction lines“Box in” the rough outline of the objectDarken only the lines you wish to keepClean up the edges and rough spots

Box In TechniqueBoxing in the outer dimensions is often the first step in producing a sketch

Sketching TipsIf you don’t have a ruler, you can estimate dimensions using your pencil when sketchingAlways keep your pencil at arms length. Why?

Sketching Tips

Layout of drawing using your pencil for dimensional reference

Lettering

The style of engineering lettering we will use in this course is Single Stroke Gothic Lettering An example of the characters is

shown on drawing numbers 1 and 2 Notice that only capital letters are

demonstrated, since we will use only capital letters on drawings

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Lettering Notes

Lettering Guidelines – HandoutLettering Styles Shape of Letters Order of Drawing LinesCharacter UniformitySpacing

Single Stroke Gothic Lettering

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Lettering – Vertical Gothic Font

Lettering with Fractions

Sketching Techniques