technical drawing Workshop Practice E102A

introduction Technical drawings: Clearly define aspects of engineered items Conform to standards Minimize confusion 1.8ish Build this!

obstacles between the real world and your drawing We live in a 3-dimensional world. Paper constrains us to 2 dimensions. You cannot easily measure a drawing.

solutions 3-dimensional objects can be represented in a 2D space by two primary methods: Orthographic Projection Isometric Projection

orthographic projection Orthographic projection uses multiple views of the subject, from points of view rotated about the subject's center through increments of 90°.

isometric projection Isometric projection captures the object from an upward angle and disregards perspective This can cause some confusing issues

dimensioning Dimensions in cooperation with a drawing should provide sufficient information to allow anyone to machine the object. With complex objects involving many dimensions, dimensioning can get messy.

dimensioning types Parallel dimensioning: Parallel dimensioning consists of several dimensions originating from one projection line.

dimensioning types Superimposed Running Dimensions The common origin for the dimension lines is indicated by a small circle at the intersection of the first dimension and the projection line.

dimensioning types Chain Dimensioning Chains of dimension should only be used if the function of the object won't be affected by the accumulation of the tolerances.

dimensioning types Dimensioning by Co-ordinates Two sets of superimposed running dimensions running at right angles can be used with any features which need their centre points defined, such as holes.

line styles visible lines - are continuous lines used to depict edges directly visible from a particular angle. hidden lines - are short-dashed lines that may be used to represent edges that are not directly visible. center lines - are alternately long- and short-dashed lines that may be used to represent the axes of circular features.

why? If you want your idea or mechanism to be seriously considered, submit technical drawing demonstrating the functionality and form.