Page 25 - 3D Metal Printing Magazine Winter 2022

CAM Software Triggers Success with DED Metal Printing 3D
traction, specifically as a result of recent software developments, we spoke with Open Mind Technologies’ managing direc- tor Alan Levine and engineer Brad Rooks. The firm supplies the hyperMill modular CAM software with capabilities for hybrid manufacturing applications combining five-axis subtractive manufacturing (milling, turning and cutting) and DED. The bonus with this type of software: Users can attain true-to-detail material application and removal simulation, as well as stock tracking between the indi- vidual machining steps, optimizing process reliability.
“Automation—in the physical sense such as using robots, programmed offline, to direct the deposition process, and within the CAM software—helps ensure a precise, repeatable DED process,” says Levine. “A state-of-the-art CAD-CAM environment automates the control of power from the energy source, material feed and the manipulator to attain the desired stepovers and other process parameters, essential to making good parts. Then, automation features within the software allow repeat- able processing of part families, where procedures that proved successful for one part easily can be captured and used with similar parts—a family of mold inserts, for example. In this way we reduce costs and streamline development time.”
“Using automated process program- ming in the CAM software,” Rooks adds, “we can take a known process and use it to program subsequent parts. We can cap- ture and color-map the surfaces that the user is depositing onto and automatically apply the correct DED tool paths so that there’s less intervention from the CAM programmer. The end user then has a pro- grammed part and established process with a known baseline. Then, when there are similarities in geometry of subsequent DED jobs, based on the way the CAD is presented we can leverage automated fea- tures in the software to program those new features with just a few mouse clicks.”
“The process has to be similar,” Levine says. “The automation works by adjusting the geometry but it’s the build process that we’re replicating.”
Relatively Unlimited Geometry
One advantage of the DED process compared to powder bed: no need for support structures. “With DED on a CNC machine, we can articulate the axes to stay perpendicular to the build and avoid the need for supports,” Rooks explains. “Automation—of both the process and programming—then contributes to the overall efficiency of the DED process.”
“With new CAD-CAM software such as hyperMill,” says Levine, “programming is
Tools often must be repaired or reworked during their production life, and the DED process can be of great help here. Adding material precisely where it is required and then re-machining the part in a single setup now can be achieved with one system.
highly flexible so that almost any tradi- tional machining process can be refer- enced for an additive DED process. Then, its broad flexibility also addresses some of the challenges related to the types of parts made. We see DED being relatively unlimited in the types of geometries that can be built, and being simpler to adopt for a new user compared to other metal- AM processes. The market will grow as more companies realize this. We see the process being used to coat some really dynamic surfaces that you wouldn’t be able to work on without these developed machine-control capabilities.”
While Levine and Rooks both note that the DED process often starts with a simple substrate—a plate for example—it then allows users to build up sections and final- machine them to precise dimensional specs.
“For example, with plastic injection molds,” Rooks says, “we can refurbish by milling off a reference layer of material to provide the base geometry for the CAD- CAM software, and then use that CAD model as the reference surface to program a new buildup with the DED process.
“We’re also hearing about some rela- tively new applications for DED,” Rooks continues, “relating to battery-cell tech- nology. DED allows for the blending of materials that comprise the inner struc- tures of a battery cell. The process can precisely interleave these materials, fully blended or layered with gradient values established by the programmer.”
Building Rotationally Symmetrical Geometries
When it comes to hyperMill CAD-CAM software supporting the DED process, all
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