June 12, 2007 | By Paul Hogendoorn
Conventional quality control in tube bending operations usually means detecting the number of links on a tube bending mandrel. When such a system detects that a mandrel link is missing, it shuts down the system so personnel can discard the last bent tube and replace the mandrel. Unfortunately, the broken mandrel link usually is a symptom of a larger problem—one that may have produced poor-quality parts long before the mandrel broke.Another method, process variation monitoring, measures the tension on the mandrel and alerts the equipment operator when the tension changes. This lets the manufacturing personnel know that a problem is developing while it is still small and manageable.
April 11, 2006 | By Paul Hogendoorn
Most manufacturers measure or test parts to verify that the parts meet quality standards. This conventional approach is time-consuming because testing adds steps and time to the production process. Furthermore, it is only as good as the sample size. A different approach to quality is to use a strain monitor to measure strain on the machine's frame. Comparing the strain with a reference (measured when the machine was known to be producing good parts) is a way to monitor the production process, and it doesn't require extra time or steps.