Tips and Tricks: Working with Spinal Bends in Creo 3.0,Tips and Tricks: Working with Spinal Bends in Creo 3.0

The Spinal Bend tool bends a solid or quilt about a curved spine by continuously repositioning cross sections along a curve. If you’re not familiar with it, you can use spinal bends for creating advanced complex geometry (like the turbo scroll in the video example below) or even something as simple as modeling an engaged zip tie in an assembly. If you are already familiar with the tool, note that the UI and some capabilities have been enhanced in Creo 3.0.

Solid before spinal bend.

Solid after spinal bend. (Notice that the system extends the length of the rod to match the length of the spine.)


By default, the Spinal Bend tool bends selected geometry along a spine to match the length of the spine. If the spine is longer than the geometry, the geometry is stretched along the spine (see image above). If the spine is shorter than the geometry, the geometry is compressed along the spine.  Also by default, the tool bends all of the selected geometry.

That said, many interesting options exist for modifying these default behaviors. For example, you can limit the length of the bend, bend just a portion of the geometry, or remove unbent geometry. The following steps and video describe how.

To Create a Spinal Bend

Before you start, note that the spine must be C1 continuous (tangent). If the spine is not also C2 continuous (curvature continuous), the feature surfaces might not be tangent. The plane that passes through the start point of the spine and is normal to the spine must intersect the original quilt or solid feature. To create a spinal bend, follow these steps:

Spinal Bend tab. Note cursor points to “specified depth” icon described in step 3 below.

  1. Select a spine for the bend, and then click Model> Engineering >  Spinal Bend. The Spinal Bend tab opens.
  2. Right click on the graphic window, select Bend Geometry collector, and then select the geometry to bend. (After the spinal bend is created, the original solid becomes invisible. However, you can still select it in the Model Tree.)
  3. Define the region to bend by selecting an option:
    • Bend the geometry from the start of the spine to its end.
    • Bend the geometry from the start of the spine to a specified depth. Type or select a depth value from the start point (selected in figure of Spinal Bend tab above).
    • Bend the geometry up to a selected reference. Select a point, a vertex, or a plane.
  4. To maintain the original length of the geometry after bending it, select the Lock Length check box.
  5. To remove the geometry that is outside of the bend region, select the Remove unbent geometrycheck box.
  6. Click the green check to complete the operation.

To see how it works, watch this short video.


There are several more options for creating your spinal bends. For example, you can specify a different start point for the bend along the spine, select a quilt rather than a solid, or control your cross section properties. For details , visit the Creo Help page