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# Applying Shrinkage by Scale

You can shrink part geometry by scaling it in relation to
coordinate system directions.
• You can apply shrinkage by scale
to all three directions uniformly.
– Isotropic
• You can apply different shrinkage
ratios to each of the three
coordinate system directions.
– X-Direction
– Y-Direction
– Z-Direction

Figure 2 – Isotropic Shrinkage
by Scale Applied
Applying Shrinkage by Scale

Figure 1 – Model Before
Shrinkage Applied

Figure 3 – Different Shrinkage
Ratios Applied to Different
Directions
The Shrinkage by Scale method enables you to shrink the part geometry
by scaling it in relation to a coordinate system. You can specify different
shrinkage ratios for the X, Y, and Z-coordinates. If you apply shrinkage
in Mold mode, it applies only to the reference model and does not affect
the design model.
Shrinkage by scale is applied by creating a new shrinkage feature. When
you apply shrinkage in Mold mode, the shrinkage feature is created in the
reference model, not in the design model, unless the Same Model option was
used when assembling the reference model into the mold model.
To apply shrinkage by scale, you must specify the following items:
• Coordinate System — Specify the model coordinate system that the
shrinkage feature uses as a reference. The X, Y, and Z-directions of
the coordinate system determine the X, Y, and Z-directions used for the
shrinkage ratio.
• Formula — Specify the formula you want to use to calculate shrinkage.
• Shrink Ratio — Specifies the ratio of shrinkage you want to apply.
The following options are available when applying shrinkage by scale:
• Isotropic — When enabled, sets the same shrinkage ratio for the X, Y, and
Z-directions. You can clear this check box to specify a different shrinkage
ratio for each of the three directions.
• Forward References — When enabled, the shrinkage does not create new
geometry but changes the existing geometry so that all existing references
continue to be part of the model. You can clear this check box to have
the system create new geometry for the part on which shrinkage is being
applied.
Considerations when Applying Shrinkage by Scale
When applying shrinkage by scale in Mold mode, keep the following in mind:
• A negative shrinkage ratio shrinks the dimension, while a positive shrinkage
ratio expands it. For example, a positive 0.02 shrinkage ratio applied with
the 1+S formula expands all the model dimensions by 2 percent, while a
negative 0.02 shrinkage ratio shrinks all the model dimensions by 2 percent.
• It is never reflected in the design model, unless the design model is the
reference model.
• If it is applied to the design model in Part mode, then the shrinkage feature
belongs to the design model, not to the reference model. Shrinkage is
accurately reflected by the reference model geometry, but it cannot be
cleared in Mold mode.
• It should be applied prior to the definition of parting surfaces or volumes.
• It affects part geometry (surfaces and edges) and datum features (including
curves, axes, planes, and points)