Bend tables for sheet metal materials

Autodesk Inventor allows flat patterns to be generated by unfolding sheet metal features using: a uniformly applied linear KFactor, a bend table or a custom unfolding equation. Because a bend table can take into account specific (nonlinear) equipment behavior, the piece parts produced from models using bend tables are closer in tolerance to the folded model.

A bend table is a table of bend deductions arranged in rows and columns. Each row specifies a bend angle while each column specifies a bend radius. When unfolding, Autodesk Inventor interpolates between adjacent values in the table if a bend radius or angle does not correspond to a specific entry.

A bend table file can contain multiple bend tables as long as the tables are for different materials or thicknesses. Typically, a bend table file contains a bend table for each sheet thickness that is used. Since aluminum deforms differently than steel, a separate bend table file should be created for each material type.

Autodesk Inventor provides an integrated editor for creating and editing bend tables. You can also edit bend tables with a text editor or spreadsheet. The integrated editor supports using either text files or spreadsheets: text files can be imported while ranges of cells can be pasted in as required. Sample bend table text files and spreadsheets are included in the following location:

Bend tables are saved as an ASCII text file (*.txt).

Note: A bend table for a particular part need only have rows for the angles used within the part. If a part only uses a single bend radius, a bend table only requires a single column. If a part only has 90 degree bends of a single bend radius, there is no benefit in using a bend table versus adjusting the uniformly applied KFactor value. A useful bend table for a particular shop floor machine has a full-range of angles and bend radii. Each cell in such a table requires measured sample pieces to ensure the highest accuracy.