Dimensional Inspection of Tube Bending

The role and impact of technology

Dimensions of a bent tube are represented by either length, rotation and angle (LRA) or XYZ coordinates. This data can be gleaned from the information provided in most specification drawings, and are the guideposts used to inspect and verify the dimensional accuracy for a bent tube or pipe.

For all bending projects, a first article inspection is required; the frequency and timing of additional inspections during manufacturing is dependent on the complexity of the part and the type of equipment used. For less-complicated bends, manual tools can be used to verify angle, length and perpendicularity. Even a tape measure has a place in certain situations. 

For more complex parts, technology is important. Specialized inspection equipment is used to provide real-time visibility to dimensions (using either LRA or XYZ coordinates) during manufacturing and gives feedback on necessary adjustments. This data can be immediately transmitted to the CNC bending machine, retained for reporting purposes and used for future projects. In contrast to a manual approach, this saves time and production hours and is highly accurate and reliable, resulting in shorter throughput to achieve a dimensionally accurate part.  

Using digital, high-definition cameras, inspection equipment visually measures the geometry and sizing of a bent tube, and verifies angles and tolerances based on the specifications in the digital file, generating a multi-dimensional image of the bent part. The cameras scan to create an outline or model of the tube to verify conformance with the parts specifications. Multiple angles are captured with the cameras, providing the operator with immediate results. The 3D digital image can be viewed at multiple angles and retained in the customer record.

Overall, inspection technology provides increased accuracy and consistency, offering real-time diagnostics that provide visibility to micro- and macro-data needed for quality assurance and verification. If needed, adjustments can be made quickly and easily, reducing handling time and allowing for greater throughput and accuracy when processing single parts, multiple batches or large-volume orders. 

This blog was authored by Randy Krickeberg, Plant Manager, Sharpe Products. Randy can be contacted at randyk@sharpeproducts.com.