Stock Machining¶
Cost impact for upgrades to aPriori Professional 2021 R1
Cost Model Version Summary¶
The following table shows the cost model version numbers for the last three major releases:
| Release | Cost Model Version | Status |
|---|---|---|
| aPriori 2021 R1 | 130 | New with this release |
| aPriori2020 R1 | 110 (20.1.0) / 120 (20.1.1) | From a prior release |
| aPriori 2019 R2 | 90 (19.2.0) / 100 (19.2.1) | From a prior release |
Summary of Platform Changes¶
The table below indicates whether there were geometry and/or cost engine changes for this process group. Such changes could impact costing results for configured Digital Factories.
| Platform Area | Was there a Change? |
|---|---|
| Geometry | Yes |
| Cost Engine | No |
Change Summary by Area¶
The table below indicates whether there were geometry and/or cost engine changes for this process group. Such changes could impact costing results for configured Digital Factories. For the first type of change (geometry or cost engine changes), the table indicates the impact level (High, Medium, Low, or No).
| Area | Impact? |
|---|---|
| Geometry or cost engine changes that might impact configured Digital Factories | Medium (can be disabled) |
| Bug fixes or small improvements to prior cost model versions that might impact configured Digital Factories | NO |
| Cost model changes that do not affect configured Digital Factories | NO |
Details: Geometry or Cost Engine Changes that Could Impact Configured Digital Factories¶
The following changes might impact costing, even for Digital Factories that use earlier cost model versions.
- Polygon Recognition: In the Stock Machining process group, aPriori now recognizes internal and external polygonal features (including hex shapes, square shapes, and other equilateral polygon shapes) and extracts them as Polygon GCDs. This new type of volumetric GCD is handled by the new machining operations Polygon Turning and Rotary Broaching. These operations are not present in older cost model versions.
If you are using a cost model based on a version from a previous release, disable polygon extraction by setting the site variable polygonExtractionEnabled to false. If you do not, some features that were previously extracted as Pocket GCDs may be extracted as Polygon GCDs instead, in which case some volumetric removal will be neglected by the cost model.
-
RingedHole Extraction: In this release, for a given internal volume that is symmetric about a turning axis, the GCDs that represent it might change compared to the previous release. aPriori uses one of the following methods to represent such a feature:
- Explicit RingedHole method: feature is represented by a SimpleHole, a Ring, or a RingedHole whose children are a central SimpleHole and one or more surrounding Rings (which represent enlargements of the hole).
- Implicit ringed hole method: feature is represented by a central SimpleHole and zero or more surrounding Rings. No parent RingedHole GCD is created.
-
MultiStepHole method: feature is represented by one or more SimpleHoles and/or one or more MultiStepHoles and/or one or more Rings if necessary. In the previous release, aPriori used the explicit RingedHole method if the site variable createRingedHole was set to GCD or MCD. It used the implicit ringed hole method if the site variable createRingedHole was set to None. In this release, by default, aPriori uses the explicit RingedHole method if the current routing is a turning routing. It uses the MultiStepHole method, by default, if the current routing is a milling routing. RingedHole extraction behavior is controlled by the site variable createRingedHoleMCD in the Machining process group. The site variable createRingedHole (introduced in Release 20.1.0) is now deprecated. The site variable createRingedHoleMCD has the following possible values:
-
All: This is the default. With turning routings, use the explicit RingedHole method. With milling routings, use the MultiStepHole method. This applies to all process groups that support RingedHoles.
- None: regardless of routing type, use the implicit ringed hole approach. This applies to all process groups that support RingedHoles.
- Net Shape Only: For net shape process groups (Additive Manufacturing, casting process groups, Forging, and Powder Metal), use the RingedHole method with turning routings and the MultiStepHole method for milling routings. For all other process groups that support RingedHoles (2-Model Machining, Bar & Tube Fab, and Stock Machining), use the implicit ringed hole method.
If you are upgrading from a release earlier than Release 20.1.0, you can generally restore the previous behavior by setting the site variable createRingedHoleMCD to its previous setting. If you used Net Shape Only previously, some behaviors may be different.
- Slot Recognition: In the previous release, aPriori extracted Slot GCDs only for traditional (full) dovetail slot features and slots with parallel walls. In this release, aPriori also extracts Slot GCDs for half-dovetail slots (also known as one-sided dovetail slots) and for modified dovetail geometry in which there is a straight-walled section below the undercut portion of the slot.
Previously these geometries typically were included in the BulkRemoval GCD; occasionally they were recognized as Pocket GCDs if they had a short, straight trajectory. In this release, as with traditional dovetail slots, half-dovetail slots are assigned (rough) slot milling and finish dovetail milling machining operations.
As a result, cycle times and costs for parts containing the new slot types increase compared to the previous release, for Digital Factories that use the new Machining cost model.
If you do not upgrade your Machining cost model to the latest version, cycle-time for one-sided dovetail slots will be overestimated and modified dovetail slots will fail to cost. Therefore, if you do not upgrade to the new Machining cost model. aPriori recommends that you disable recognition of these new slot types by setting the new site variable slotExtraction2Enabled to false.
Details: Bug Fixes or Small Improvements to Prior Cost Model Versions¶
The following changes might impact costing for Digital Factories that use earlier cost model versions.
- NO IMPACT
The Stock Machining process group may be impacted by the changes in the Machining process group. Please review the impact assessment in the Secondary Machining process group.
Details: Cost Model Changes that Do Not Affect Configured Digital Factories¶
The following changes do not affect costings with Digital Factories that use earlier cost model versions. The changes are available only in the latest cost model version.
- NO IMPACT