Laser Tracker Integral to Mobile 5 Axis Smart Machining Processes

As smart factory processes have improved over the last two decades, machine tool designs and processes have remained largely static. Their accuracies and efficiencies have improved at regular intervals, but many manufacturers have taken an “if it isn’t broken, don’t fix it” approach to out-of-the-box to tool design and functionality. Metrom set out to change this mentality.

Since 2008, Metrom have specialized in mobile 5-axis machine tools that can move around the component for faster, more flexible machining. In recent years, Metrom has partnered with API to use the Radian Laser Tracker to streamline these processes and guarantee their accuracy. Working together the companies have been able to:

• Create new streamlined processes for work on large components
• Reduce downtime for part movement and shipping
• Expand the applications and accuracy for mobile machining

Mobile 5-axis Machine Tools Specialist Receives Innovation Awards

Metrom has been a manufacturer of processing machines based on patented parallel kinematics since 2001. Since 2008, these machines have also been supplied in particular as mobile 5-axis machine tools, which move on and around the component and do not, as is usually the case, machine the component inside a structure.

For this, Metrom has already been awarded the Saxon Innovation Prize 2009 and the Intec Prize 2011. To expand the applications, capabilities, and accuracies, Metrom began looking for a metrology partner that not had only equipment, but creative solutions to develop new processes. For these applications of mobile machining, API’s Radian Pro Laser Trackers have proven themselves perfectly as cost-effective and robust 3D measuring systems.

Successful initial test collaboration with Radian Laser Tracker

In 2017, Metrom and API started their first collaboration on a project in Denmark with Global Castings and other industry participants from the region. By jointly checking the application possibilities of Laser Trackers when moving the mobile processing machine on a rotor hub with subsequent measurement of the scar, the basis for new efficient processing possibilities on large components was created.

Use with API Laser Tracker as a service – also for digitizing and reverse engineering 

Since then, the knowledge gained from the project has been applied to other major projects, which involve the production of a tongue-and-groove joint for the fabrication of reactor joints.

Based on their first experiences with API’s technician (and the needed flexibility for their own implementation), 5-pm UG purchased their own Laser Tracker from API in 2018. Since 2018, 5-pm UG has been offering mechanical processing with the mobile Metrom machine and, in combination, calibration or separate measurements using the Laser Tracker as well as digitizing and reverse engineering using the laser scanner.

Very good results on a test component with 2m diameter

For Harald-Liebers-Behälter-und Apparatebau in Chemnitz, a test machining was carried out on a component with a diameter of 2 meters in the run-up to the planned main machining in order to prove the step-free machining during a complete milling of a tongue and groove contour on the circumferential plane. The results were extremely satisfying, and the project (planned with the mobile machine plus Laser Tracker) was scheduled for about 1 year later.

Convincing advantages: Mobile component measurement of huge components on site 

Machining of the real tongue and groove geometry for the 4 segments of a polymerization reactor was then carried out on site at the Harald-Liebers plant. The segments each had a weight of approx. 65 tons, a diameter of 5.5m and a length of 35m. A special transport with permits for 2 federal states would have been necessary to transport each of the 4 components to a correspondingly large processing center. The machining per area took 4 days, including the measurement. During processing, the components were left on the roller stand support, which was already used for the previous welding work. No special equipment or requirements for the environment were therefore necessary.

Perfect accuracy and project planning advantages

The result of the measurements after machining speaks for itself: across a diameter of 5.5m, the process maintained an accuracy of 80µm. Possible deformations could be compensated during the machining process, so that later assembly of the segments worked without problems. In addition to the achieved accuracy, a part ready for acceptance was produced directly in the factory and subjected to a pressure test by means of removable clamp flanges. The ex works delivery was thus error and risk free for the customer.

Clear time frames could be kept by the close cooperation, and the polymerization reactor was then perfectly installed in Turkey in the 4 segments, finally welded, and put into operation.

Further joint applications with the Laser Tracker in the future

In the future, mobile machining on a Metrom system will be supplemented by additive manufacturing using welding processes, since there is an increasing demand not only for machining but also for repair in one clamping at the customer’s site. Furthermore, application cases with the Laser Tracker will be extended for applications into new scenarios. “The Metrom and API mobile machining solution offers a fast measurement possibility and a robust system at the machining site.” says Marcus Witt, Chief Technology Officer at Metrom.

For more information: www.apimetrology.com.