Parallel motion

Manual drafting of design and construction drawings is generally carried out on a drawing board. The drawing board provides a large flat surface to which paper can be attached for the drawing to be created.

Some drawing boards include a parallel motion. This is typically a horizontal guide that is attached to cables, guides or counterweights at either end that allow it to move up and down along the surface of the drawing board so that lines can be dawn that are parallel to one another. Used in conjunction with set squares or protractors and rules, that can slide along the top or bottom edge of the guide, this allows lines to be drawn at any required angle at any point on the paper.

Less expensive drawing boards may use a T-square to achieve a similar result. T-squares are T-shaped guides that are not fixed to the drawing board. The head of the T-square is pushed against the edge of the drawing board and the edge of the blade can then be used to draw lines parallel to the edge of the drawing board.

Some drawing boards have a vertical rather than horizontal parallel motion, and some include complex arrangement of connected arms or rules fixed to the board that allow lines of any angle to be drawn.

[edit] Related articles on Designing Buildings

• Blueprint.
• Drawing board.
• Manual drafting techniques.
• Model.
• North American Paper Sizes
• Paper sizes.
• Perspective.
• Projections.
• Scale drawing.
• Scale rule.
• Scale.
• Symbols on architectural drawings.
• T-square.
• Technical drawing pen sizes.
• Technical drawing.
• Techniques for drawing buildings.
• Types of drawing.