Beckhoff’s TwinCAT 3 NC I Designed for Precision in Polishing and Grinding Robotics

March 02, 2021 by Stephanie Leonida

Beckhoff expands its efforts with the TwinCAT 3 NC I software, to improve the precision and efficiency of its automated polishing and grinding machines.

PMA Pacific Machinery Company Limited (PMA Pacific) is headquartered in Suzhou Industrial Park. The company aims to provide sustainable, efficient, and customizable automated polishing and metal grinding solutions.

PMA Pacific serves as the production center, service base, and sales headquarters of abrasive belt grinding machines from Peitzmeier Maschinenbau GmbH in the Asia-Pacific region.

Peitzmeier's machines integrate Beckhoff's PC and EtherCAT-based control and drive technology, including its TwinCAT 3 NC I software.

Polishing and metal grinding solutions provide food and beverage, pharmaceutical, and packaging industries with finely polished customized engineering. This is due to the processing workpieces ranging from cabinets and cases, kitchenware covers, and parts for packaging machines. 

As opposed to manual polishing and grinding, an automated alternative can generate high-quality polished products with a lower risk of contamination and reduce labor intensity.

Automated polishing and grinding can also reduce health risks concerned with metal dust produced from grinding entering the eyes and lungs. 


TwinCAT Enables Complex Motion Control

The idea is to combine robotics, PC-based, and TwinCAT motion control capabilities to enhance newly developed robot polishing and grinding machines.

This development can reduce labor costs and increase the efficiency of grinding and polishing processes. 


Robot-based polishing and grinding machine. Image courtesy of Beckhoff


In a news release from earlier this month, General Manager at PMA Pacific, Yue Yang Zhu, provided his comments, "PC-based control technology from Beckhoff is flexible and enables convenient programming of even complex algorithms. TwinCAT offers an extensive range of functions to meet the general requirements of polishing and grinding machines." 

PMA Pacific's new abrasive belt grinding machines incorporate a high-performance CX2020 Embedded PC and a CP2915 multi-touch Control Panel, an AX8000 multi-axis servo system, and AM8000 servomotors. 

The system also includes TwinSAFE components for enhanced safety. The EtherCAT-based drive system underpinning the machines combines Field Programmable Gate Array (FPGA) technology and multicore Advanced RISC Machines (ARM) processors. 

Together, this combination may enable quicker sampling and response times to streamline speed and current control cycle times of 16 µs.


TwinCAT 3 NC I Software

TwinCAT stands for The Windows Control and Automation Technology and forms the basis of the control system. The TwinCAT software system can turn nearly any other PC-based system into a real-time control with multiple PLC, NC, CNC, and robotics runtime systems.

The new robotic polishing and grinding machines use Beckhoff's TwinCAT 3 NC I software.


The software enables the realization of the robot's path movements through teaching points on the touch screen. Image courtesy of Beckhoff


During sheet metal part grinding, the TwinCAT 3 NC I software can realize movements of three-axis interpolation and five auxiliary axes. Another feature of the software is the ability to reconfigure axes in groups, execute path override, slave coupling to path axes, auxiliary axes, axis error, sag compensation, and measuring functions. 


Increasing Robot Precision

The G-code (DIN 66025) instructions and transitions of TwinCAT NC I can help robots pass through teaching points with precision and improve engineering efficiency.

Other features of the software include additional language extensions with structured text (GST), interpreter and geometry functions, and alternative access through function blocks according to (International Electrochemical Commission) IEC 61131-3. 

In the same news release, Yue Yang Zhu concluded, "PC-based control technology provides the great advantage for us that we can realize the use of robots on polishing machines by integrating motion control, robotic algorithms, and visualization. The universal and integrated control architecture simplifies engineering and reduces the total cost of the solution."

PMA Pacific's new twin belt grinding machine, the OG-Twin-3107-AF, along with Beckhoff's TwinCAT 3 NC I software, is suitable for kitchenware and cabinet manufacturing and multi-variety production.