Bend lines are not generated in 2D views, and the part cannot be bent back

Problem

Bend lines are not drawn in the 2D flat pattern view.

Solution

In case of problems, go through the following checklist:

• Ensure that the bend area geometry is valid. For example, poorly created fillets that extend into the bend area may interfere with the flat pattern, causing bend lines not to be generated.

• Verify that the surfaces to be flattened are not spline surfaces. Spline surfaces may cause bend lines not to appear. The issue can be resolved by modeling the part differently. Another option is to draw the bend lines manually in the 2D drawings.

Invalid geometry in sheet metal bends may also cause other issues with sheet metal parts.

You can display the surface type by enabling the option "Show geometry hint at cursor" in user settings. After this, hover the cursor over a surface in the model and keep it still for a moment to see the surface type.