by Kip Hanson
Additive comes on strong in the fabricating space
Few would argue that additive manufacturing (AM) has had a significant impact on the machining world. Prototypes that used to take weeks or months to deliver can now be produced in a day or two. End-use parts and assemblies that once required multiple machining operations, costly workholding and hours of engineering and programming work are now 3D-printed in a single, unattended step. Plastic injection moulds with conformal cooling channels are now possible due to 3D printing, as are complex shapes that were previously impossible or at least impractical to manufacture.
None of this implies that modern machine tools are going the way of CAM-actuated lathes and mechanical tracer mills. Quite the contrary—3D printing and CNC machining complement each other in ways that no one could have predicted a decade ago. But where does that leave sheet metal fabricators, welding houses, and tool and die manufacturers? Good question.
Shop Metalworking Technology had a chance to speak with three leaders in the additive equipment space to see what effect 3D printing is having on the non-chipmaking parts of the manufacturing world. Their answers might surprise you.
Go Big or go home
Berlin-based BigRep GmbH is a leading manufacturer of large-format FFF (fused filament fabrication) 3D printers and solutions. The company’s BigRep PRO printer boasts a one-cubic-metre build space and advanced extruding technology that managing director Martin Back says is ideal for a range of industrial applications utilizing high-performance, engineering-grade polymer filaments.
New York-based Boyce Technologies, for example, uses its BigRep to print “mass customized” cooling system ducts and similar components for its line of communication kiosks, drastically reducing product development time. J.C. Steele & Sons Inc. of North Carolina says its BigRep has reduced expenses by 75 per cent and increased annual production by more than 50 per cent by 3D printing sand casting patterns. Ford Motor Co. uses large format printing for welding jigs and fixtures, while Kawasaki builds tooling for its CNC tube bending machines. The list goes on.
“BigRep’s industrial 3D printers are routinely used for batch production of end-use products, as well as factory tooling and large format rapid prototyping,” he says. “Given the current adoption level, we predict an ongoing increase in the use of additive manufacturing for production purposes, in many cases replacing cutting, bending and welding, as well as tools to improve these traditional processes.”
Hey, SAAM!
Alex Riestenberg, additive manufacturing product manager at Cincinnati Inc., sees things a little differently. Although his company also manufactures large-format 3D printers—in this case, the BAAM (short for Big Area Additive Manufacturing), the largest of which has a 6.1 x 2.3 x 1.8 m (240 x 90 x 72 in.) build area, and the all new one-cubic meter MAAM (Medium Area additive Manufacturing)—he says the majority of fabricators are more interested in Cincinnati’s much smaller printer, the SAAM.
“The BAAM is quite popular for making moulds, patterns and autoclave tooling, primarily in the aerospace industry, but we also see it used for full-size prototyping in automobile and heavy truck applications,” he says. “The SAAM, on the other hand, really shines for quick-turn press brake tooling. This includes custom die sets as well as back gauge stops, functional gaging, robotic end effectors, and so on.”
This trend has grown with the introduction of Cincinnati’s SAAM HT. Thanks to a heated 200 x 190 x 240 mm (7.9 x 7.4 x 9.4 in.) build chamber, 250°C (482°F) heated print bed, and 500°C (932°F) extrusion nozzle, it’s now possible to print polycarbonate, PEEK, ULTEM, and similar high strength polymers able to withstand the extreme forces generated in press brake operations.
The biggest challenge for fabricators, Riestenberg notes, is learning how to utilize the new technology, and understanding the many opportunities it presents. “We’ve seen a ton of growth over the last couple of years, but especially on the additive side,” he says. “Even in our own shop, we’re always finding new ways to use it. For example, the press brake people are always asking about 3D printed tooling and gauges. You can make scale models of large parts and machinery for visualization purposes. There are countless 5S (sort, set, shine, standardize, sustain) uses for 3D printing, replacement parts for equipment, prototyping and low-volume production…having that capability readily available makes a lot of sense for any shop.”
Old technology, new solutions
Each of the solutions just discussed is limited to polymers, which is perfectly fine for many applications. But what about those where the greater strength and durability of metal is needed? Mark Douglass, business development manager at Ohio-based Lincoln Electric Additive Solutions, has an answer. It’s called wire arc additive manufacturing, or WAAM, and although you can’t yet own one, Lincoln Electric is happy to work with you on any large-scale metal tooling or parts you might require.
“We’ve been working on metal additive for about a decade but opened our doors as a service provider in early 2019,” says Douglass. “Our customers provide us with a CAD file that we process using proprietary software and deliver to one of our robotic additive cells for manufacturing. As for the types of parts we can print, I tell people anything larger than a basketball, but one good example is a fairly large Invar aerospace tool we’re currently working on. It measures four feet across (1.2 m), five and a half feet tall (1.7 m), weighs around 1,500 pounds (680 kg), and would have taken several weeks to construct using traditional means, followed by extensive machining afterwards. By comparison, we usually turn things like this around in a week or two, with less time needed on the back end for post-processing.”
Robots and arc welding have been around for decades. Shops have used cladding to repair parts and create hard surfaces for even longer. In fact, inventor Ralph Baker filed a patent on the use of “arc welding for the formation of deposits to produce receptacles or containers of ornamental and useful shapes” way back in 1920. So why did WAAM take so long to develop? As Douglass explains, it’s the software that’s been the biggest roadblock.
“That’s the trick,” he says. “Unlike cladding, metal additive can be used to generate very complex, three-dimensional shapes to a much higher degree of accuracy, and do so without voids or other metallurgical defects. You need sophisticated software for this, not only to control the robot but to develop the deposition paths necessary to assure a robust build, otherwise the process gets out of control. That’s what we’ve done, and it’s something that we feel will bring a great deal of value to the fabrication industry.” SMT
