About Sheet Metal Styles

Sheet metal parts can often be fabricated using various materials with minimal impact to the part functionality. Changing the material of a sheet metal part from aluminum to stainless steel requires changes to the attributes which define bends and corners and often requires changes to the shop floor machinery and set-ups used to fabricate the parts. Sheet metal styles capture the following:

• Complete material definition
• Bend relief shape and size
• Bend radius value
• GapSize parameter value
• Bend transition type
• 2-bend corner relief type and size
• 3-bend corner relief type and size
• Unfold method
• Custom unfold equations (when defined)
• Flat pattern punch representation definition
• Flat pattern bend angle reporting preference

All these attributes are now collected into styles which are created and managed using the Style and Standard Editor and which can be saved and globally shared through the Style Library (in early releases of Inventor these styles were saved and managed though the use of template files).

Sheet metal parts provide the same appearance, lighting style, and material settings as regular part files. Additionally, sheet metal parts will include a:

Sheet Metal Rule - Sheet metal parts made of the same material and thickness will often share common bend, corner and gap parameters. These settings and attributes are collected into a sheet metal rule that also contains preferences for the:

• representation of punch features
• bending angle or open angle reporting option

when the part is shown in the flat pattern state.

Sheet Metal Unfold Rule - Sheet metal parts are defined by their folded or functional state but are fabricated from a flat sheet. The bends that are applied to the flat pattern deform the material within the bending zone. The amount of deformation depends on a number of variables. Transforming the folded model to the flattened state requires accounting for this deformation using one of three methods:

1. a general mathematical approximation using a defined KFactor
2. empirical values captured in a bend table for specific materials, bend angle values and tooling
3. custom equations that provide for user-specific refinements when solving using the: bend compensation, bend deduction, bend allowance or KFactor approach

The method and settings are collected into an unfold rule which (when used with the sheet metal rule and material) allows maximum flexibility in the design of parts which may be manufactured of different materials using diverse manufacturing options.

Sheet Metal Style Migration from pre-R2010 Files

The objective of the migration task is to maintain legacy sheet metal style data. For a given sheet metal file, migration will:

• Migrate the active style information to an appropriately named local style or rule
• Migrate the inactive style information to appropriately named local styles or rules

Following migration:

• There will be no impact to the size or shape of the sheet metal part
• Unused styles or rules will be available for potential reuse or uploading to the global styles library

Prior to R2010, the management of sheet metal styles was accomplished exclusively at the document level. Templates were often created that contained all sheet metal style definition within a single file. In R2010, all defined styles within a sheet metal component are migrated (not just the active style). Additionally, all unfold methods listed for each sheet metal style (including those not referenced) are also migrated.

New for R2010 is a significant change to unfold methods and how they are managed. During the process of migrating files created prior to R2010, unfold methods are promoted to a new type of style that is called a Sheet Metal Unfold Rule. Named Sheet Metal Unfold Rules can be declared to be a part of a named Sheet Metal Rule. Use this new structure to leverage, reuse, and manage Sheet Metal Unfold Rules easily.

In legacy sheet metal styles, material style and thickness values were predefined and controlled by the selection of a given sheet metal style. In R2010 this convention is still utilized, allowing Sheet Metal Rules to drive the definition of material styles and thickness values as well as the Sheet Metal Unfold Rules.