Mold Dimensions
Estimates for mold dimensions are a factor in both machine selection and tooling cost estimates.
The mold dimension estimates are based on the following factors:
• Cavity dimensions (see Part Length, Width, and Height)
• Undercut depth information (see Undercut Depths)
• Clamp force used (see Required Clamp Force)
• Number of mold cavities (see Number of Mold Cavities)
Mold Length = Cavity Length * Lengthwise Number of Cavities +
Mold Border on –L Side +
Mold Border on +LSide +
Lengthwise Gap between Cavities * (Lengthwise Number of Cavities – 1)
Mold length is the sum of the following:
• Cavity length * lengthwise number of cavities (see Part Length, Width, and Height and Number of Mold Cavities)
• Mold border on the –L side (see Mold Borders)
• Mold border on the +L side (see Mold Borders)
• Lengthwise gap between cavities * (lengthwise number of cavities – 1) (see Gaps between Cavities)
Mold Length = Cavity Length * Lengthwise Number of Cavities +
Mold Border on –L Side +
Mold Border on +LSide +
Lengthwise Gap between Cavities * (Lengthwise Number of Cavities – 1)
Mold width is the sum of the following:
• Cavity width * widthwise number of cavities
• Mold border on the –W side (see Mold Borders)
• Mold border on the +W side (see Mold Borders)
• Widthwise gap between cavities * (widthwise number of cavities – 1) (see Gaps between Cavities)
Mold Borders
Each of the following considerations imposes a minimum size on mold borders:
• Clamp force: the border must be large enough to withstand the required clamp force (see Required Clamp Force). As the clamp force increases, the minimum border size increases. aPriori looks up the minimum border size by clamp force in tblMoldBorderXDirection (for the –L and +L borders) and tblMoldBorderYDirection (for the –W and +W borders).
• Slides: the border on a given side must be large enough to accommodate any slides that might be present on that side of the cavities (see Undercut Depths). As the specified undercut depth for that side increases, the minimum border size increases. Note that the increase in mold size is significantly greater than the undercut depth, since a slide mechanism is considerably larger than the largest undercut it handles. See Slide Lengths for more information.
The cost model estimates the border size as the larger of these two minima. That is, the cost model uses either the border size required by the clamp force or the border size required by the slides, whichever is larger.
Gaps between Cavities
Each of the following considerations imposes a minimum size on the gaps between two cavities:
• Clamp force: gaps must be large enough to withstand the required clamp force (see Required Clamp Force). As the clamp force increases, the minimum gap size increases. aPriori looks up the minimum gap size by clamp force in tblSlidelessGapBetweenCavities.
• Slides: the gap between two cavities must be large enough to accommodate any slides that might be present on the cavity sides that flank the gap (see Undercut Depths).
The lengthwise gap between two cavities must accommodate any slides on the +L side of one of the cavities as well as any slide on the –L side of the other cavity.
The widthwise gap between two cavities must accommodate any slides on the +W side of one of the cavities as well as any slide on the –W side of the other cavity.
As the specified undercut depth for that side increases, the minimum border size increases. Note that the increase in mold size is significantly greater than the undercut depth, since a slide mechanism is considerably larger than the largest undercut it handles. See Slide Lengths for more information.
The cost model estimates the gap size as the larger of these two minima. That is, the cost model uses either the gap size required by the clamp force or the gap size required by the slides, whichever is larger.
Slide Lengths
Slide lengths contribute to mold size (see Mold Dimensions).
Slide Length = Undercut Depth + (Multiple * Part Height) + Slide Clearance
Slide length is the sum of the following:
• Undercut depth (see Undercut Depths)
• Multiple of part height (see Part Length, Width, and Height)
• Slide clearance
Multiple = {
1.5 if Part Height <= 152.4mm;
2 otherwise}
Multiple is one of the following:
• 1.5 (if part height is less than or equal to 152.4mm)
• 2 (otherwise)
Slide Clearance = {
5.0mm, if Number of Cavities == 1;
12.7mm otherwise)
Slide clearance is one of the following:
• 5.0mm (for single-cavity molds)
• 12.7mm (for multi-cavity molds)