In that case, you might want to check out the EBAM 300 from Sciaky (Chicago), whose work envelope is 19’ [5.8 m] x 4’ [1.2 m] x 4’ [1.2 m]. EBAM, or electron beam additive manufacturing, is Sciaky’s trademarked technology for using beams of the negatively charged particles to additively manufacture parts from virtually any open market wire metal feedstock, including high-value materials like titanium and tantalum.
Sciaky (see-ACK-ee) says EBAM has a deposition rate of 7 to 20 lb (3.1 to 9 kg) of metal per hour. Its machines can be equipped with a dual wire feed for custom alloys, and the dual feed can be adjusted to create graded parts.
Lockheed Martin is using Sciaky’s EBAM to make titanium propellant tanks for satellites. Other technology partners include the Department of Defense, U.S. Air Force, Boeing, DARPA and Pennsylvania State University’s Applied Research Laboratory.
The Chicago-based company displayed its additive technology in September at IMTS 2016 in Chicago, along with familiar names that are newer to the large-format process, 3D Platform (Roscoe, IL) and Stratasys (Eden Prairie, MN).
In fact, 3D Platform introduced its new, large-format platform at IMTS. The Excel 100 has a build area that measures 4’ [1.2 m] x 4’ [1.2 m)] x 8’ [2.4 m], but can be extended to any length needed.
“We have focused on large-format because it depends on motion control,” said John Good, vice president of sales and marketing for 3D. “And that’s where our DNA is.”
The Excel series features a parallel gantry configuration that can support multiple, simultaneous materials and processes, including additive, subtractive and robotics-assisted manufacturing, using filament or pelletized feedstock. The Excel’s extruders deposit plastics from 4.4 lb [2 kg] per hour to as high as 121 lb [55 kg] per hour per gantry.
3D Platform’s machines are designed to use a variety of open market materials created for fused filament fabrication.
The Excel machine takes up 5’ [1.5 m] x 10’ [3 m] on the shop floor: an optional heated enclosure for use with higher-engineered plastics, designed to print at a higher heat, measures 21’ [6.4 m] x 9’ [2.7 m].
“It’s a big machine, it’s a beast,” said Good. “But what we’re trying to show is scalability.”
Defying Gravity/Eliminating Layers
While Sciaky and 3D Platform’s machines print on a horizontal plane, Stratasys flipped the work bed 90 degrees on its Infinite Build, one of two additive manufacturing demonstration machines the company introduced at IMTS.
The Infinite Build is designed to print big thermoplastic tools and production parts using Stratasys’ fused deposition modeling, but on a vertical plane. The vertical design created challenges for research and development engineers at Stratasys, who weren’t used to having to defy gravity.
In the Infinite Build, the work piece adheres to a build sheet, made of a similar plastic, which attaches to the machine’s vertical wall. Supports keep the object from deforming due to gravitational pull, explained Amy Sissala, print quality engineer in Stratasys’ research and development department. Her job in Infinite Build’s development was to coordinate the mechanical movements of the machine with its screw extruder movement.
“We had to rethink how to support the parts we print,” Sissala said.
When the work piece’s height reaches up to ½-2” [12.7 to 51-mm], the vertical wall moves away from the robotic arm. The ultimate height of the object being manufactured is limited only by the size of the building the machine is in.
Plans are to introduce Stratasys’ proprietary FDM thermoplastics one at a time for use with the Infinite Build. So far, the R&D people have used Ultem 9085, polycarbonate and nylon.
Sissala explained the Infinite Build’s screw extruder dispenses micro-pellet feedstock faster than ever, increasing the machine’s throughput. Also speeding things up are linear motors on the machine’s gantry vs. ball screw motors, she said.
In addition, the machine is equipped with sensors to detect anomalies in the pressure of the plastic it’s extruding. If the sensors detect the wrong pressure, it’s possible for the robotic arm to correct the process by changing tools automatically.
Also at IMTS, Stratasys unveiled its Robotic Composite AM machine, a technology that forgoes the process of making composites layer by layer.
“One of the big limitations in composite techniques and also in 3D printing is the layering technique,” said Clint Newell, director of Advanced Manufacturing Technologies at Stratasys and the visionary behind the Robotic Composite machine. “With robotics, we have 8 axes of orientation (six in the robotic arm and two in the work piece platform) that completely eliminate the need, in many cases, for support material.
This reduces build time by as much as three-quarters.”
The Robotic Composite machine incorporates industrial motion control hardware and end-to-end workflow software from Siemens (Washington, DC).
To date, the R&D teams’ focus for feedstock in the Robotic Composite’s multiple extruders has been on using filament or pelletized engineering-grade thermoplastics and chopped fiber made of carbon or glass, and more. They’re also looking at using continuous fiber, Newell said.