1 Reading a Drawing or Sketch Identify types of working and pictorial drawings commonly used for blueprints. Identify and Describe the five main types of lines used in drawings. Explain the system of dual dimensioning.

2 Drawing and Sketches n A drawing or sketch is a map you follow when making a project. It tells you: u exact size and # of parts. u how the project fits together. u style of joinery. u construction details. n There are two main categories of drawings. u Pictorial Drawings F shows the way the project looks. u Working Drawings F shows specific views of a project.

3 Pictorial Drawings n Pictorial Drawings show how a project will look. u ISOMETRIC u CABINET u PERSPECTIVE

4 Isometric Drawings n An isometric drawing has parallel lines drawn at angles of 120 degrees. u Advantages F Easy to understand F Works well with simple projects. u Disadvantages F Difficult to create when project is complex. F Does not “truly” represent the look of the finished project.

5 Cabinet Drawings n In a cabinet drawing the front of the object is drawn normally however the sides of the drawing are at an angle of 30 or 45 degrees. u Advantages F easy to understand details of front view. F Relatively simple to create. u Disadvantages F Distorted view of sides. F Not appropriate for more complex sides.

6 Perspective Drawings n A perspective drawing looks like a photo with one or two vanishing points. u Advantages F looks better F gives user a clearer representation of what the finished product will look like. u Disadvantages F Difficult to draw, especially when curves and irregular surfaces are present. F Does not allow for many dimensions to be located on drawing.

7 Working Drawings n Working drawings are used for construction of the project. These drawings often show 1,2,3, or more views of a part. Often called multi-view or orthographic projections. u Part dimensions are located along the edge of the views. u Views are placed in correct relationship to each other. F Advantages easy to create once you understand the basics. Details a LOT of information. F Disadvantages takes time to learn to understand and interpret.

8 Assembly Drawings n Assembly drawings are used to show the relationship of parts in a project and how they go together. u Often called “exploded” drawings. u Very useful for new woodworkers.

9 Detail Drawings n Detail drawings are used to show up close details of a project. Often including: u moulding profiles u assembly techniques u Glue-up instructions u ?????

10 Lines used in Drawings n Visible Line u shows the project and its outline. n Hidden Line u Indicates the outline of surfaces that cannot be seen from the given view. n Center Line u Shows the center of circles, arcs, or divides the drawing in two. n Extension Line u Extends from the object, allowing to show dimensions away from the project. n Dimension Line u Usually has arrowheads at each end gives the dimensions.

11 Dual Dimensioning System n With the prevalence of the metric system in society today, plans often include both standard and metric dimensions on the same drawing When this technique is found on a woodworking plan we can it Dual Dimensioning. u Saves the inconvenience of converting to your preferred units. (1” = 25.4 m.m.) u May use an equivalent size chart to keep drawing cleaner. NOTE: This technique can still have flaws as conversion from standard to metric can create difficult to measure, odd lengths. (ex. 1”=25.4 mm) It is better to design the project in metric if it is to be constructed with metric units.

12 Variations in Project Plans n Drawings for projects do not follow rigid rules. It may be common, actually expected, to find plans that include more than one style of drawing. The drawings chosen to represent a projects can be affected by: u what is appropriate for the project. u Skill level of person creating drawing. u Skill level of intended craftsperson. u Other??? NOTE: All plans and drawings are not created equal. When choosing a project, especially as a beginning woodworker, select those of high quality, that are clearly understood. The small expense pays for itself by reducing errors and increasing satisfaction during the construction of the project.