To Create a Cross Section Driven Unbend
1. Click > > 
Cross Section Driven Unbend. The (Xsec Driven Type) dialog box opens and the CHAIN menu appears.
Cross Section Driven Unbend. The (Xsec Driven Type) dialog box opens and the CHAIN menu appears.2. Select the needed attachment chain and options on the CHAIN menu.
3. Click Done after selecting the edges needed.
4. Define the curve to control the cross sections as they unbend:
◦ Select Curve—Selects a curve on a plane that is coplanar with the fixed edges.
◦ Sketch Curve—Sketches the cross section curve. The curve can be a straight line.
5. Define the side of the bend to remain fixed: Okay or Flip to change the direction.
6. Click OK. The unbend is created.