Methods Machine Tools Inc. (Sudbury, MA), a leading supplier of precision machine tools, 3D printing technology and automation, recently introduced an automation cell designed to greatly boost 3D manufacturing throughput. The cell, which Methods said is a first-of-its-kind, combines additive manufacturing with robotics and subtractive processes, providing fast, efficient finished 3D part production.
The 20′ Methods cell includes an in-feed station for 3D printed parts, still attached to their build plates. From there, a FANUC robot shuttles the plates into a FANUC C600 EDM, which makes a partial cut between the parts and build plates. In the next station, the same FANUC robot snaps each printed part from its plate and transfers it to a FANUC RoboDrill for final machining. The robot then moves each completed part to a finished pallet. When the last part from a build plate has been completed, the robot moves the plate back to the EDM, which removes the remnants of the 3D printed support structures, effectively recycling the build plate for another 3D print job. The robot then puts the trimmed plate on the conveyer for transfer back to the 3D printer.
John Lucier, national automation manager for Methods, said the cell can be adapted to any 3D printed output, but would generally not interface directly with the 3D printer itself since virtually all 3D printed components require initial post-processing before machining. For example, 3D printed (laser sintered) metal parts would typically require heat treatment immediately after the build, a process usually performed off-site. On the other hand, Lucier said, “if the volumes justified it, we’d love to automate the process of removing parts directly from the printer and loading them into the heat treat oven and out again, and then conveying them to the machining cell.”
Methods introduced the cell at the RAPID + TCT show in May, where, according to Lucier, the excitement seemed to focus on the final machining of the parts. That seems odd, because many 3D printed parts need to be machined to meet their intended use since their geometric accuracy and surface quality is roughly the same as a casting. As Lucier put it, “we automatically load and then machine castings on RoboDrills all the time. That’s not what’s special here. What is special here is the cutting of the parts from the build plate. We’d normally get discrete parts from a saw, a box, a bin, or some other receptacle. Here, we had to come up with a way to cut parts from a plate and reliably locate them to autoload them into the mill. The key was making a partial cut and using the robot to make the final break.
“This automated lights-out manufacturing cell was designed to drastically reduce the total time to complete parts from 3D printing to final post-processing.,” he continued. “It can easily quadruple total part throughput while eliminating manual labor.”