Bar and Tube Fabrication Enhancements

Improved Stock Shape Recognition for User-Selected Overrides

aPriori 2026 R1 SP2 introduces an improved stock shape recognition algorithm for Bar and Tube Fabrication that gives users more flexibility to override the automatically-selected stock form. Previously, when aPriori did not automatically identify the desired stock form, manually selecting the desired stock form often failed because the same strict geometry checks applied to both automatic and user-selected recognition.

In this release, if you enable the new stock-shape recognition algorithm, aPriori extracts an extrusion profile and uses it to shrink-fit your requested stock shape to the part, allowing aPriori to accept a much wider range of user-selected overrides regardless of how closely the final part geometry matches the standard stock specification.

Eanble the new, shrink-fit algorithm by setting the site variable enableUserStockFormShrinkFit to true.

Note

In cases where the stock is heavily machined to produce the final part, or where the user’s stock selection does not closely reflect the actual part shape, the shrink-fit algorithm may select a stock that requires significant material removal. In some cases, this material removal is not yet accurately represented as GCDs, and therefore the manufacturing operation and cycle time estimate to perform the material removal may ne inaccurate.
See the examples below.

Consider the following example parts:

Example 1

This is a rectangular tube with two walls completely cut away. By default aPriori determines the stock form is Generic Extrusion. In previous releases, you could not successfully override the stock form to Rectangular Tube:

In aPriori 2026 R1 SP2, the new shrink-fit algorithm allows the manual override to Rectangular Tube:

However in this example the ComplexHole GCD includes the inner wall surfaces and does not include one of the two surfaces that are cut away. Cycle time and cost estimates for that material removal likely are inaccurate. This type of issue occurs when the complete cross-section of the stock form does not remain intact anywhere on the part.

Example 2

This is another part that is made from rectangular tube and is initially recognized as a Generic Extrusion. In this case, when the user overrides the stock form to Rectangular Tube, aPriori creates ComplexHole and End GCDs that correctly capture the material that needs to be removed , supporting an accurate estimate (see highlighted GCDs below):

Note

Due to the limitation in the first example and the potential for inaccurate material removal estimates, the new algorithm is disabled by default in aPriori 2026 R1 SP2 (site variable enableUserStockFormShrinkFit = false). Users who are having difficulty selecting the correct stock shape are encouraged to enable this feature by setting the site variable to true, but should review results carefully to be aware of potential under-estimates or over-estimates. aPriori plans to enhance the manufacturing process model to more broadly support machining of standard stock forms in a future release.