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LO6 - Coggle Diagram
LO6
Dimensions
TYPES OF DIMENSIONS
Dimensioning of small features
arrow heads placed outside the extension lines instead
Dimensioning of multiple features
use n x dimension
Dimensioning of radius
shows a radius dimensioned with the centre of radius located on the drawing
Rules of dimensioning
Avoid dimensioning to hidden lines and features
Dimension lines, extension lines and object outlines should not cross or overlap
Dimensions should not be repeated
Tolerance
The Importance of Tolerance
Tolerance will ensure that mating parts of an assembly interface and fit well
The range of tolerance will translate into the manufacturing method needed, since different manufacturing method has different degree of tolerance
if tolerance is not given,exact measurement of the parts must be made. Rejection rate will be very high and is not realistic
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Tolerance ensures good quality control for parts from different companies
Types of Tolerance
Bilateral Tolerance
allowed to vary in two directions from specified dimension
Unilateral Tolerance
only allowed to vary in one direction
Limit Tolerance
the upper and lower limits of the dimension are specified
Assembly models
multiple parts that are brought together to define a larger and more complex product presentation
Dimensions
TYPES OF DIMENSIONS
superimposed running dimension
simplifies parallel dimensions in order to reduce the space used on a drawing
Parallel dimensions
consists of several dimensions originating from a common reference surface
Chain dimensioning
used only when function of object would not be affected by the accumalation of tolerances
Combined dimensioning
uses both chain and parallel dimensioning