Customizing Tooling Costs for Transfer Die
Following is a selection of some of the important, controllable factors that affect tooling costs:
Post-form Trimming
The cost model assumes that after forming has been performed, direct or cam trimming is required for blank edges that have tight tolerance.
Post-form trimming is triggered for edges whose positional tolerance is tighter than the threshold specified by the cost model variable edgeTrimmingPositionToleranceThreshold (2mm in starting point VPEs). If you haven’t specified the positional tolerance of an edge, the cost model assumes the tolerance specified by the cost model variable defaultPositionToleranceEdgeSegment (1.5mm in starting point VPEs). Note that all tolerances are bilateral; positional tolerance specifies the diameter of the tolerance zone. See also Die Station 2: Edge Trimming, Direct Piercing.
The cost model variable enableMultiStationTrimming controls whether trimming is distributed over two die stations (instead of using just a single station) if the trimmed scrap length exceeds a certain threshold. In starting point VPEs, enableMultiStationTrimming is set to false, so trimming is always contained to a single station. In this case, if the trimmed scrap length exceeds the threshold, additional tooling costs for scrap breakers are incurred instead of the cost of an additional station.
The scrap length threshold is specified by the cost model variable maxScrapSizeThreshold (457.2mm in starting point VPEs). This variable limits the size of the scrap pieces produced by edge trimming. If enableMultiStationTrimming is true, edges longer than the threshold require two edge trimming operations on two separate stations, rather than just one.
See also Edge Trimming, in the Quick Start.
Post-emboss Piercing
The cost model assumes that piercing operations must be performed subsequent to the Embossing operation, for holes that either have tight tolerance or intersect the embossed form. (Piercing is always performed subsequent to drawing.) Piercing after embossing can sometimes increase tooling costs by increasing the number of die stations or requiring a cam for piercing.
Post-emboss piercing is triggered for holes whose positional tolerance is tighter than the threshold specified by the cost model variable holePiercingPositionToleranceThreshold (2mm in starting point VPEs). If you haven’t specified the positional tolerance of a hole, the cost model assumes the tolerance specified by the cost model variable defaultGcdPositionTolerance (1.5mm in starting point VPEs). Note that all tolerances are bilateral; positional tolerance specifies the diameter of the tolerance zone.
See also Cam Trimming and Piercing below.
Cam Trimming and Piercing
Trimming a blank edge and piercing a hole requires a cam if the feature is not accessible from a direction that is sufficiently close to the ram direction. You can customize what counts as sufficiently close with the cost model variable maxRamDirectionTangentAngle (30 degrees in starting point VPEs). See also Edge Trimming, Cam Piercing, and Cam Bundling for Transfer Die.
Scoring, Tapping, Coining, and Shaving
Some operations are performed only if enabled, and can be disabled or enabled by the following setup options:
Restriking
In starting point VPEs, restriking is performed on a form if any of the following conditions hold:
• Material strength: selected material has a tensile yield strength that exceeds 344.74 N/mm2. You can customize this threshold with the cost model variable matlYieldStrengthRestrikeThreshold.
• Width-to-depth ratio: the form’s width-to-depth ratio is less than 0.5. You can customize this threshold with the cost model variable widthToDepthRestrikeThreshold. The width-to-depth ratio is the SER Width divided by the sum of Depth Up and Depth Down.
• Depth-to-thickness ratio: the ratio of the form’s depth to the blank’s thickness is less than 1000. You can customize this threshold with the cost model variable depthToMatlThicknessRestrikeThreshold. The depth-to-thickness ratio is the sum of Depth Up and Depth Down divided by the material thickness.
• Minimum radius of curvature: the form’s smallest radius of curvature is less than 10 times the blank thickness. You can customize the blank thickness multiplier with the cost model variable minRadiusOfCurvatureRestrikeThresholdMultiplier.
• Surface tolerance: the tolerance some surface of the form is tighter than 0.5. You can customize this threshold with the cost model variable minFormSurfaceToleranceRestrikeThreshold.
Restriking can occur on the same die station along with multiple other operations, providied those operations are not occurring on the surfaces being restruck and do not otherwise interfere with the restriking operation and tooling.
See also Die Station 3: Restriking.
Blank XY Orientation
By default, parts are oriented in the XY plane so as to minimize transfer pitch. You can control the part orientation with the setup options Blank XY Orientation within the Transfer Press and Determine Transfer Pitch Based on:.
Ram Direction
The choice of ram direction affects tooling cost by requiring or eliminating tooling components (such as lifters for down bends). You can modify the default choice of ram direction with the ram direction tool, , in the Viewer toolbar. See Ram Direction for Transfer Die.
Number of Concurrent Parts
In starting point VPEs, one part at a time is stamped at each station, by default. Stamping two parts concurrently can decrease cycle time, but it can increase tooling cost. For progressive die, you can control concurrency with the setup option Number of Concurrent Parts in Transfer Press.
Die Shoe Dimensions and Spacing
Transfer pitch is the blank pitch—see Blank Pitch—plus twice the value of the cost model variable dieShoeLengthAllowance (203.2mm in starting point VPEs), plus the value of the cost model variable interDieSpacing (25mm in starting point VPEs). Die shoe width (perpendicular to the pitch direction) is the value of the cost model variable dieShoeWidthAllowance (304.8mm in starting point VPEs).
Miscellaneous Setup Options
See the following setup options:
You can also specify the number of die stations directly by editing the number of occurrences of the Die Set component-level operation.