How to Build a Better Rat Trap—with 70 Synchronized Servo Axes
People often fixate on how to build a better mousetrap. An equally important pursuit, according to systems integrator Mitec Enginy, is figuring out how to build a mousetrap better. And combining both goals, the northern Spain-based automation experts have developed a sophisticated manufacturing system to produce traps for household pests.
The machine’s core element is a revolutionary motion control system with a total of 67 servo axes synchronized by camming function. The result is a production line that feeds, cuts and bends wire; produces springs; and mass-produces the final product—a rat trap—in just 1.5 sec. In addition to the servo drive technology, Beckhoff also supplies the required control performance with PC-based control, EtherCAT networking and TwinCAT automation software solutions.
Mitec Enginy has been developing and integrating application-specific automation systems for customers around the world since 2006. According to Managing Director Albert Gratacos, the engineering company focuses on innovation in the automation of industrial processes, the modernization of a variety of machines and the implementation of comprehensive solutions.
Servo Drive Technology Replaces Mechanics
“Looking back at the history of automation, it is essential to appreciate the foundations that are simply taken for granted today,” Gratacos explained. “Eighty years ago, mechanically driven machines were quite common, often powered by a motor and connected by gears, crankshafts and cams. These inventions still drive our innovations today, yet these machines predate 3D CAD, CNC machining and software. With today’s technology, mechanical machine components are replaced by multi-axis servo movements and controlled more reliably and flexibly by software.”
For a prime example, consider the latest application from Mitec Enginy—the rat trap machine. “The customer needed to modernize their product manufacturing to remain competitive, so we devised an appropriate way to do that,” said Gratacos. “At first, the idea of precisely synchronizing around 70 servo axes sounded almost crazy, but it ultimately proved to be the right solution for the complex process sequences, and we were able to implement it using PC-based control from Beckhoff.”
The system relies on 61 AX51xx and AX52xx servo drives paired with 67 AM80xx servomotors to power the various process steps. In terms of software, TwinCAT 3 with the camming function (TF5050 TwinCAT 3 NC Camming) ensures precisely synchronized motion sequences.
The EtherCAT industrial Ethernet system delivers optimal communication for motion control as a high-speed, high-bandwidth and extremely deterministic fieldbus. Ideal for all things motor- and drive-related, EtherCAT can handle the most basic PTP systems to advanced applications, such as the Mitec Enginy machine. In addition, EtherCAT supports safe motion functionality.
The rat-trap machine implements all necessary safety functions (STO, SOS, SS1 and SS2) directly in the automation system with TwinSAFE and Safety over EtherCAT communication. A Beckhoff CX2062 Embedded PC serves as the central controller, offering core processing power using advanced Intel Xeon processors.
These features delivered serious competitive advantages, according to Lluis Moreno, sales engineer at Beckhoff Spain. “[The solution] is fully equipped with powerful servo drive technology networked via EtherCAT and can be reliably coordinated with the CX2062 from just one computer,” Moreno said.
Complex Solutions Require a Strong Team
Mitec Enginy’s success can also be attributed to the team that has been created to develop complex automation solutions.
“We handle all of the mechanical and electrical design, programming and assembly of the automation in-house. At the same time, we recognize that no one person can be the expert for the entire automation system, which is why we have specialists in mechanics, electrics and programming working closely together to develop innovative automation solutions,” said Gratacos, who also credited customers and suppliers as project partners.
Among the many projects Beckhoff has partnered on with Mitec Enginy, none have captured Morena’s interest more than the rat trap machine: “I have to admit that the current production line is the most efficient and, dare I say, ‘beautiful’ machine in terms of design so far; each of the many movements is just so fast, precise and smooth that no unnecessary stresses are transferred to the mechanics of the machine.”
Matt Prellwitz is drive technology product manager for Beckhoff Automation LLC.