Design Drawing Formats

WhiteLight Design uses standard practices for generating and formatting product development Layout Drawings. Layout Drawing plans are typically prepared in a standardized Architectural or Engineering orthographic (front, top, side) view formats. Layout plans are generated on standard (A) 8-1/2″ x 11″ , (B) 11″ x 17″ office-sized paper or on larger (C) 17 x22″, (D) 22″ x34″ and (E) 34″x44″ size sheets in units scales based on the U.S./ inches foot or metric system. The choice of scale depends on the end product scale, but full scale is preferred unless the product to is big to fit on the selected size paper. Preferred layout formats including use of the US engineering scale (10 – 1000 increments per inch ) or Metric (Millimeter and Meter) or architectural (2 – 64 increments per inch). hand drawn skecthes or thumbnail – line drawings are commonly used to visualize in 3D, to generate accurate projection representations of the product. Isometric and perspective – line and shaded or color rendered views are used to communicate marketing level 3D form and geometry, styling and appearance. Drawing formatting is very important to generating CAD models as well as the USPTO patent process and the required exact drawing, layout, line quality and shading requirements, to meet the application and patenting process.

Drawing – Format
Scale & Units: United States (Imperial) & Metric units
In the United States, and prior to metrification in Britain, Canada and Australia, architect’s scales were marked as a ratio of x inches-to-the-foot (typically written as x”=1′-0″). For example one inch measured from a drawing with a scale of “one-inch-to-the-foot” is equivalent to one foot in the real world (a scale of 1:12) whereas one inch measured from a drawing with a scale of “two-inches-to-the-foot” is equivalent to six inches in the real world (a scale of 1:6). Typical scales used in the United States is full scale, with inches divided into tenths or sixteenths of an inch.

The following scales are generally grouped in pairs using the same dual-numbered index line:

(3″=1′-0″) three-inches-to-the-foot  (ratio equivalent 1:4)/one-and-one-half-inch-to-the-foot (1-1/2″=1′-0″) (1:8)
(1″=1′-0″) one-inch-to-the-foot  (1:12)/one-half-inch-to-the-foot (1/2″=1′-0″) (1:24)
(3/4″=1′-0″) three-quarters-inch-to-the-foot (1:16)/three-eighths-inch-to-the-foot (3/8″=1′-0″) (1:32)
(1/4″=1′-0″) one-quarter-inch-to-the-foot (1:48)/one-eighth-inch-to-the-foot (1/8″=1′-0″) (1:96)

Metric units
In Britain the standard units used on architectural drawings are the SI units millimeters (mm) and meters (m), whereas in France centimeters (cm) and meters are most often used. In Britain, scales often found on architect’s scales are:

1:1/1:10
1:2/1:20
1:5/1:50
1:100/1:200
1:500/1:1000
1:1250/1:2500
Scale
Plans are usually scale drawings, meaning that the plans are drawn at specific ratio relative to the actual size of the place or object. Various scales may be used for different drawings in a set. For example, a floor plan may be drawn at 1:50 (or 1/4″=1′-0″) whereas a detailed view may be drawn at 1:25 (or 1/2″=1′-0″). Site plans are often drawn at 1:200 or 1:100.

Architect’s or An Architectural scale 1/4″ = 1′-0″ is US based fractions of an inch based on increments to foot An architect’s scale is a specialized ruler. It is used in making or measuring from reduced scale drawings, such as blueprints and floor plans . It is marked with a range of calibrated scales (ratios). A device for drawing straight lines is a ruler. In common usage both are referred to as a ruler not to be confused with a weighting scale.

Engineers scale   An Engineering scale defines scale based on the U.S. inch or EU meter divided into tens or thousands, increments to the inch/foot or meter (cm/mm) One half scale 0.50 = 1.0 or one tenth scale 0.10 = 1.0 or one tenth = one foot/meter or one-tenth size” The scale was driven from mass production when machined parts and components and manufacturing equipment required a greater precision to accommodate tolerance fits, for example, in laying out printed circuit boards with the spacing of leads from integrated circuit chips as one-tenth of an inch. The engineering scale is the standard used in industrial design, mechanical and manufacturing engineering to define, design and measure parts to see if they meet specifications.

In Canada and the United States, this scale is divided into decimalized fractions of an inch, but has a cross-section like an equilateral triangle, which enables the scale to have six edges indexed for measurement. One edge is divided into tenths of an inch, and the subsequent ones are directly marked for twentieths, thirtieths, fortieths, fiftieths, and finally sixtieths of an inch. Scale model kits are standardized for the EU. On a metric engineer’s scale, common scales are 1:100, 1:200, 1:250, 1:300, 1:400, and 1:500. In English-speaking countries, such terms as “1/72″ were used, but the format with a colon as “1:72″ is preferred or “1:72.5″  The metric and US systems can also be mixed, such as “4 mm:1 ft” or “1 mm:3 in”, but the dimensionless form makes conversion more convenient.

Choice of Scale
The choice of scale is really a matter of who’s going to prototype and manufacturer it. For example the nominal height of a man in the US, inch-based system: is approximately six feet. Many traditional scales are derived so that a common figure, such height can be simple relation or proportions such as six feet or 72 inches. The metric system has specified scales for CAD – CAM applications, however when it comes to models, there are conversion issues, for example the nominal man is 180 centimeters. Additionally, in scale landscape and railroad models the conversion gauge is a simple number, the height of a person being secondary. Trade authorities in metric countries are attempting to specify scales that are simple multiples of 2 and 5, but neither tracks nor people seem to fit. In such cases, rationalization may actually be invoked for competitive advantage, to prevent interoperability with products from another manufacturing country.

Military and industrial development traditionally uses the metric system where the number of millimeters relate to the relative height of the human figure based on 180 cm. Therefore, 25 mm scale refers to 1:72 scale, the 15 mm scale is 1:120. Manufacturers refer to 15 mm as 1:100 scale). The 50 mm scale is the same as 1:35 military model scale and 5 mm equals 1:350 naval scale. The choice is typically based on the Designer common practice and knowledge of the end manufacturers needs. In product development, when CAD – CAM modeling in the US inch system, be aware that when converting to the metric system, the conversion numbers and are not convenient to work with and can stretch out 5 to 7 decimal places long, i.e. 10mm = .39370 inches. Likewise, conversion from metric to us also brings in uncommon numbers, i.e. 3/32″ or .09375 inches = 9.525 mm or 3/16″ or .375 inches = 4.7625 mm.

Views and Projections
Because plans represent three-dimensional objects on a two-dimensional plane, the use of views or projections is crucial to the legibility of plans. Each projection is achieved by assuming a vantage point from which to see the place or object, and a type of projection. These projection types are:

Orthographic projection, including:
Plan view or floor plan or top view
Elevation, usually a ‘head-on’ view front of an exterior of the product
Section, a cutaway view of the interior of the product
Isometric projection
30 degree x 60 degree x 90 axis grid
30 degree x 30 degree x 90 axis grid
Prospective projection
1 point perspective (room view)
2 point perspective (2 left / right – vanishing points)
3 point perspective (2 left / right and base vanishing points)