Datum Dimensioning
This section shows how to create datum dimensions.
Datum dimensioning is useful to mark holes and other features on a part. The dimensions are parallel to each other (like chain dimensioning), and have a common datum point. Normally, design engineers use this type of dimensioning for parts that will be NC machined.
The three datum dimension commands are:
• DATUM LONG: creates dimensions using long base lines.
• DATUM SHRT: creates dimensions using short base lines.
• COORDINATE: creates dimensions without dimension lines. Useful if the geometry of the part will cause the dimension lines to be too close together.