Robotic Grippers Optimized with nTopology and Desktop Metal 3D Printing

Our regular readers will know that Executive Editor Joris Peels is enthusiastic about application-specific 3D printing endeavors, seeing the benefits additive manufacturing (AM) can bring to everything from nozzles and heat exchangers to heat sinks and filters. Yet another specific use case has been demonstrated by Preziosa Francesco SRL, an Italian manufacturer of sheet metal cabinets, which has relied on nTopology’s software to optimize grippers for their robotic manufacturing operations.

To maintain an edge in their sector, the firm purchased a robotic cell and an automated press brake bending machine worth hundreds of thousands of euros. The Fanuc M710-iC robotic arm would load metal sheets onto an automatic press brake bender, then orient and hold the part as it was bent before placing the component into the proper basket for storage. However, the need to CNC machine custom robot grippers for specific jobs resulted in long lead times. For this reason, they partnered with Add-it and brought gripper production in-house with metal 3D printing from Desktop Metal.

To produce the proper grippers, capable of precise positioning under high loading conditions, the engineers at Add-it sought to improve the traction pattern on the gripper. They incorporated a honeycomb-style perforation pattern onto the gripper that increased traction. Using nTopology’s Topology Optimization tools, they then created a slimmer design for the gripper, allowing it to reach the press brake in a safer and more repeatable fashion. By optimizing its geometry, the gripper maintained the same stiffness, grip force, and weight but with a more compact footprint.

The grippers were ultimately 3D printed in 17-4 PH stainless steel using the Desktop Metal Studio System. The parts were produced in just four days, compared to the two weeks required for CNC’d variants. Weight was reduced from 32 to 40 percent, while costs were cut by 35 percent.

“If you don’t have a very repeatable process, you are forced to run production only during the day. It is very economically difficult to have these machines operate during day-shift only. Theoretically, you can have a very clever production system. But if it doesn’t work as intended because of a cheap part, an investment worth hundreds of thousands is at stake. nTopology allowed us to use robotic manufacturing our Desktop Metal Studio System to its full potential,” said Marco Preziosa, CEO of Preziosa Francesco SRL.

The benefits of 3D printing end effectors has already been explored by a variety of firms, with some specifically using the technology to create grippers for soft robotics. Now that nTopology has released the third major update for its software, however, there are sure to be more unique case studies for this and other applications.

Crucially, the update includes GPU acceleration that makes it possible to achieve a 10 to 100 times increase in performance for visualizing complex geometries. Design changes can be previewed in real-time, previously almost impossible in simulation-based software such as this.