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DIMENSIONING. Why are dimensions needed? ANSI Standards What style of dimensioning should be used Where should the dimensions be located Which dimensions are needed. READING DIRECTIONS for DIMENSIONS. UNIDIRECTIONAL (Preferred for Mechanical Drafting) ALIGNED - PowerPoint PPT Presentation
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DIMENSIONING1. Why are dimensions needed?
2. ANSI Standards 1. What style of dimensioning should be used
2. Where should the dimensions be located
3. Which dimensions are needed
READING DIRECTIONSfor
DIMENSIONS
• UNIDIRECTIONAL
(Preferred for Mechanical Drafting)
• ALIGNED (For Architectural Drafting)
• UNIDIREC TIONAL
ALIGNED
READING DIRECTIONSfor
DIMENSIONS
UNIDIRECTIONAL ALIGNED (Preferred) (Architectural)
STANDARDS FOR DIMENSIONING
• Fine solid line (Fine Solid Line)
ARROWHEADS
• General Rule:
KEEP ARROWHEADS SMALL!
GENERAL RULES FOR DIMENSIONING
• Place dimensions on the views that show the true shape of the object.
PREFERRED AVOID
GENERAL RULES FOR DIMENSIONING
• Unless absolutely necessary, dimensions should not be placed within the views.
AVOID
AVOID
GENERAL RULES FOR DIMENSIONING
• If possible, dimensions should be grouped together rather than scattered about the drawing.
GENERAL RULES FOR DIMENSIONING
• Dimensions must be complete, so no scaling of the drawing is required. It should be possible to determine sizes and shapes without assuming any measurements.
GENERAL RULES FOR DIMENSIONING
• Draw dimension lines parallel to the direction of measurement. If there are several parallel dimension lines, the numerals should be staggered to make them easier to read.
GENERAL RULES FOR DIMENSIONING
• Again, make sure there is no assuming any measurements.
• Dimension: length, width and heights.
GENERAL RULES FOR DIMENSIONING
• Dimensions should not be duplicated unless they are absolutely necessary to the understanding of the drawing. Omit all unnecessary dimensions
GENERAL RULES FOR DIMENSIONING
• Plan your work carefully so the dimension lines do not cross extension lines
GENERAL RULES FOR DIMENSIONING
• Circles, holes and Arcs
GENERAL RULES FOR DIMENSIONING
• COUNTERSUNK
• SPOTFACED
• COUNTERBORED
GENERAL RULES FOR DIMENSIONING
• Diameter Symbol is not necessary if the dimension is on the circular view itself.
• When the method on the right is used, only half a right side is needed.
GENERAL RULES FOR DIMENSIONING
• Leader Lines always point to the center of the circle
GENERAL RULES FOR DIMENSIONING
• Arcs are dimensioned by giving the radius, • The capital letter R indicates that the dimension is a
radius
GENERAL RULES FOR DIMENSIONING
• Round
• Fillet
Round
Fillet
• Location Dimensions-– Show where but now size
GENERAL RULES FOR DIMENSIONING
GENERAL RULES FOR DIMENSIONING
CORRECT
NO! NO!NO!
NO!
GENERAL RULES FOR DIMENSIONING
CORRECT NO!
GENERAL RULES FOR DIMENSIONING
CORRECT NO! NO!
GENERAL RULES FOR DIMENSIONING
LINEAR DIMENSIONS
GENERAL RULES FOR DIMENSIONING
LINEAR DIMENSIONS
GENERAL RULES FOR DIMENSIONING
What does this symbol mean?
GENERAL RULES FOR DIMENSIONING
• ANGULAR DIMENSION
GENERAL RULES FOR DIMENSIONING
ELIMINATE ONE
GENERAL RULES FOR DIMENSIONING
GENERAL RULES FOR DIMENSIONING
GENERAL RULES FOR DIMENSIONING
GENERAL RULES FOR DIMENSIONING
GENERAL RULES FOR DIMENSIONING
