Dimensioning 

 What is a Working Drawing?

  • A drawing from which a Trades person could build the object as specified.
  • A drawing must have all the necessary views to explain the shape.                     
  • A drawing must have all the dimensions and specifications needed to build the object to size, using the proper materials.

Ask Yourself – “Can this object be built without further instructions.”

Dimensioning Rules

  • There are approximately 500 rules - too many to remember.
  • You must learn to use references and textbooks for examples.

Basic Dimensioning Rules:

  1. Dimension lines are spaced 10mm from the object and 8mm apart from each other.  Overall dimensions should be placed outside smaller dimensions and should not cross.
  2. Do not duplicate dimensions (one change should be all that is necessary). 
    • Do not over dimension - only what dimensions are needed to build it.
  3. Usually dimension on the view that will be easiest to understand which is usually:
    • First on the front view
    • Secondly on the top view
    • Lastly, if needed, on the side view.
  4. Usually dimension:
    • Between the views
    • To the right side of the view.
  5. Avoid dimensioning to or from hidden lines.

Parts of Dimensions

The computer does most of the work for you when dimensioning – you just specify the start and end points and how far from and what side you want the dimension to be located

To make changes to the settings in the computer program you need to understand the parts (names) of the dimension.