dimensions, tolerances and assemblies
dimensions
parallel dimensioning
superimposed running dimensioning
chain dimensioning
combined dimensioning
dimensioning small features
dimensioning of multiple features
dimensioning of radium
dimensioning of circle, arc and hole
dimensioning angles
rules of dimensioning
dimensions and drawings must be neat
every feature must be dimensioned once
dimension lines, extension lines and object outlines should not cross or overlap ; dimensions should be placed outside the object
avoid dimensioning hidden lines and features
dimension features or surfaces should be done to a logical reference point
tolerances
bilateral tolerances : allowed to vary in two directions from the specified dimension. Both directions need not vary by the same amount.
Unilateral Tolerance: allowed to vary in only one direction
Limit Tolerance: the upper and lower limits of the dimension are specified
tolerances formula : upper limit-lower limit
types of fit
clearance fit : maximum shaft diameter is smaller than the minimum hole diameter
interference fit : minimum shaft diameter is larger than the maximum hole diameter
assembly modelling
In an assembly model, multiple parts are brought together to define a larger, more complex product representation.
types of join
rigid join : fixes two components to one another; it provides no degrees of freedom.
revolute join : has a single rotational degree of freedom, much like a hinge.