Dimension Notes

Dimensions:
ANSI
American National Standards Instatute
They decide the standards for all drafting.
Why we dimension:
          Describe
          Locate details
The Big Three Dimensions:
-Width
-Depth
-Hieght

These are the first dimension always applyed while dimensioning a part.
Never apply two of the same dimensions on a drawing especially when you are dealing with three different views.
Always apply them in between views if possible ( Not always possible if dimensions get crowded).

The X, Y, Z
The normal axis points Y being Up/down, X being Side to Side,  and Z being Front to back.

Basic rules:
Make its convinient
No calculations necessary
No Double dimensions

Lines and Dimensions should be:
Lines and symbols inside lines if possible
If not put them outside

Extension:
1/16 in gap
No gap between extension line and center line

Leaders:
Leader scales = dim scale
Circles arch notes
Run at angle to show it's not part of the drawing
Short horizontal 1/4" tail
No Horizontal or Verticle angles
Not thru corners and short as possible

Linear Dims
H/W/D
In between views if possible
Where detail is best described
Don't dim hidden lines
Smallest dim are closest to part
No calculations
No double dims

Angle dims:
Same angle as object being drawn
Use degree symbol (##D)

Circuler dims:
Arc (less then full circle)
Circle use diameter
Arc us radius
Cylander in profile (Where it is best described)
Indicate finished surfaces.