MAKING A PICTORIAL SKETCH

Pictorial sketches allow the viwere to see details of an object in only one view. There are three types of pictorial drawings; oblique, isometric, and perspective. Isometric views are the most ocmmonly used because they show the true size on each side drawn. Oblique views are typically used when the object being drawn is a cylinder. a circular form or furniture.
Step 1 - ANALYZE THE OBJECT.
Study the object to determine the length, width and height. Determine the type of pictorial view (isometric, oblique or perspective). Select a proportional grid size (1/4" or 1/8") to represent a unit of measurement (1/4", 1/2" or 1") and the type of paper (plain white or graph) to work on.
Step 2 - LAYOUT THE AXIS FOR AN ISOMETRIC SKETCH.
Begin at a point to the right and below the center of the sheet. At this point sketch three axis (one vertical, one to the right at a 30° angle from horizontal and one to the left at a 30° angle from horizontal). The three axis should form a "Y" on the sheet.
Step 3 - ADD DIMENSIONS TO THE AXIS.
Estimate the height on the vertical axis and mark it with a dash. Estimate the width on the axis to the right and mark it with a dash. Estimate the length on the axis to the left and mark it with a dash. If the measurements do not fit in the space available, use a larger sheet of paper (11" x 17" or 17" x 22") or reduce the proportions of the views.
Step 4 - BLOCK IN THE VIEWS.
Sketch very light construction lines parallel to the axis to form a box that the object will fit in.
Step 5 - LOCATE DETAILS.
Use very light construction lines to locate changes in the shape of the object and to show the location of holes or rounded corners.
Step 6 - ADD DETAILS.
Use very light construction lines to create a diamond that represents the diameter of holes or the radius of rounded corners. Sketch in the holes and rounded corners using one or more arcs.
Step 7 - DARKEN VISIBLE LINES.
All lines that represent visible edges of the object should be shown as solid thick lines.
Step 8 - ERASE EXCESS LINES.
Hidden lines or center lines are NOT shown.

NOTE: Construction lines DO NOT need to be erased as they should be drawn very lightly.

revised: 9/17/06