In the past free-form tubes were in demand primarily from the furniture business for design reasons, these days demand is generated from all industrial areas. Consequently, more tube benders need the right measuring systems which take the particularities of complex free-form tubing into account. This is where Aicon's optical measurement system TubeInspect offers an ideal solution. It carries out very precise testing of free-form tube geometries with the help of high-resolution digital cameras. But now Aicon has gone one step further: With immediate effect the company based in Braunschweig (Germany) offers an additional interface that connects TubeInspect directly with the free-form bending machine. This results in automatic correction values being identified for the formed tubes and transmitted to the bending machine. Thus set-up time is shortened considerably. A close cooperation with the bending machine manufacturer Wafios from Reutlingen has made this new development possible.

Peter Seidel, Sales Manager of the Tube Business Unit at Wafios, explains how this cooperation came about: "It's really important to us that our customers not only get the most innovative bending technology but, parallel to this, get reliable testing methods to carry out their quality assurance. That's why when Aicon approached us about working together, we immediately agreed to being a development partner for a direct interface between free-form bending machines and TubeInspect."

But why is correction on free-form bending machines so complicated? In contrast to tubes manufactured conventionally by draw bending which consist of calculated lines and bends and which feature constant radii, free-form tubes which are manufactured by push bending have a completely different set of parameters. In a CAD system they are often shown as a spline, a tube geometry in which, theoretically, at any point a different radius can exist. When correction takes place on a conventional bending machine, only the LRA values at the individual bending points have to be corrected. In comparison to this, to achieve the desired tube geometry using free-form bending, a multitude of different settings on the bending machine have to be adjusted and the bend radii optimized until the exact tube form has been bent. This set-up has - to date - been an unbelievably time-consuming process with high material usage, so that both automation and shortening of the process were the two main aims. Now TubeInspect has mastered this challenge with the newly developed interface which enables smooth communication between the bending machine and the measurement system.

A practical example: The demand for free-form bent tubes has increased dramatically especially from the automotive industry. Dr.-Ing. Werner Bösemann, Managing Director of the company Aicon 3D Systems, explains the reasons why: "Design demands or technical necessities call for tube forms, which often can no longer be manufactured on conventional machines. Maximizing efficiency however is another reason why many companies are migrating from conventional bending processes to free-form bending. One of our customers is currently testing the possibility of manufacturing its brake lines using push bending, a form of free-form bending. Their calculations show that employing this method would achieve significant cost-reduction, as the bending time per tube is lower." The company which already has a TubeInspect system can, thanks to Aicon's new development, connect the measuring machine directly to the Wafios tube bending machine B10 or the BMZ series and in doing so considerably reduce set-up and cycle time.