by Kip Hanson
Three surprising examples of how 3D printing is changing the world of manufacturing
Unless your shop is tucked away on the northernmost fringe of the Yukon Territory with no access to the Internet, television, or trade publications such as this one, you’ve at least heard of 3D printing. From printed aircraft components to personalized tennis shoes to replacement parts for ailing or injured human beings, additive manufacturing (AM) gives designers an opportunity to boldly go where no designer has gone before, creating complex shapes and structures previously impossible to produce. As a result, this now 30-something technology is drastically changing the way we think about manufacturing and manufactured goods. Here are a few examples.
Let’s start with cars. Any automotive engineer will tell you the vehicles of tomorrow need to be made lighter but still strong enough to protect their precious cargo. Hot-stamped components and advanced high strength steels go far to meet this need, but the next generation of passenger cars and fleet vehicles will rely heavily on 3D printed composites for everything from ultralight bumpers to bespoke steering wheels.
“We have a number of examples of fairings, doors, and similarly complex curved structures that are challenging to produce with traditional composites, but due to our ability to leverage 3D printing’s design freedom coupled with the strength of composite materials, automated manufacturing of these and other shapes is increasingly feasible,” says Scott Sevcik, vice president of manufacturing solutions for 3D printing pioneer Stratasys Ltd.
It was a group effort. The 3D printing part of that equation comes from Stratasys and its FDM (fused deposition modeling) technology. The automation is thanks to a six axis Kuka robot equipped with a two axis positioner. The motion control comes from Siemens and its Sinumerik CNC. And the composites? They’re a souped up and far more flexible version of the material used to build wing and fuselage structures in modern aircraft. By mounting an FDM deposition head to the business end of the robot, then loading it with a proprietary “chopped up” carbon fiber-filled nylon, Stratasys has developed a system that competes with and in many ways supersedes existing carbon fiber layup technology.
It’s not quite ready for prime time. The first Robotic Composite 3D Demonstrator unit debuted at the 2016 IMTS, and Stratasys is now “having conversations” with potential early adopters. If successful, it promises to make traditional carbon fiber processing methodologies obsolete. “We have a number of interested customers, predominately leaders in the aerospace and automotive industry,” Sevcik explains. “As we have seen with the evolution of traditional 3D printing, we anticipate that these OEMs will work with us on further developing the technology, then ask their supply chain to implement it with production applications.”
A similar story is shared by Peter Gratschmayr, vice-president of sales and marketing at Midwest Engineered Systems Inc. (MWES), except that the material in this case is titanium or alloy steel rather than advanced polymer. Using a Kuka robot not unlike that found in Stratasys’ composite demonstrator and a hot wire laser welding unit from Miller Electric, the system integrator has developed a highly accurate additive manufacturing cell.
“While working on a few very large format, high precision automation projects, we found ourselves pushed into an arena where we had to use a laser-based welding technology,” he says. “We thought at first it would be cost prohibitive, but after establishing relationships with several people in academia, the laser optics arena, Miller Electric, and the people from Kuka, we learned that diode-based lasers can provide the heat sources and optics needed to achieve the weld quality we’re looking for, but at a price point that wasn’t available in the past.”
The system started out as an automated welding cell, one able to join sheet metal components up to 40 m long (130 ft) with penetration accuracy to within 10 microns (0.0004 in.). Through that effort, however, Gratschmayr and his team soon determined that their efforts have far greater potential than a supersized laser welding station.
“We were able to make a system that actually builds the weld up into 3D printed components,” he says. “Compared to competing hybrid laser based systems that use blown powder to build parts, wire deposition allows us to use a material that’s readily available, standardized, and much closer to solid material to begin with, reducing concerns over porosity and based on welding guidelines that are well established. The closed-loop feedback system allows us to dynamically change the power and speed of the wire and the robot to create the best geometry possible. It’s also substantially faster than competing systems, with deposition rates up to 14 kg/hr (30 lb) of steel or stainless steel.”
Nowhere is 3D printing more exciting than the possibility of making replacement parts for human beings. The promise of new hearts, livers, kidneys, and bones (all of which are currently in development) is important to all of us, but especially so to those afflicted with life-altering diseases and disabilities.
Mike Nickell has multiple sclerosis (MS), a currently incurable auto-immune disease that attacks the fatty sheath (called Myelin) surrounding human nerves, particularly in people between the ages of 20 and 50. As an application engineer at machine tool distributor Ferro Technique Ltd., Nickell was given a unique opportunity recently to raise awareness of MS.
“I was working our booth at the Canadian Manufacturing Technology Show when the guys from Autodesk came over to talk about a demo they wanted to do at our next open house,” he says. “They showed me the model, my boss and I both liked it, so we decided to give it a go.”
The model he’s referring to is a replica of the human spine, something that’s quite relevant to Nickell considering the disease’s effect on the brain and spinal column. Yet this most central piece of any person’s anatomy is quite complex, and they soon realized a novel approach would be needed to reproduce it. They contacted Renishaw.
“Though not an actual workpiece, the spine demonstration represents the entire workflow of an additively manufactured medical component,” says Mark Kirby, additive manufacturing business manager for Renishaw (Canada) Ltd. “We printed it on a Renishaw AM machine, used a Doosan five axis machining centre to finish machine it, and NC-PerfectPart software to program the toolpaths.”
“It was a fun demo,” adds Nickell. “It allowed us to show off some of what can be done today with additive and subtractive manufacturing. More importantly, it helped illustrate the need for additional research into the causes and possible treatments for MS. Canada has the greatest number of MS patients in the world. Nobody really knows why that is, and it’s kind of ironic seeing that I was born in the UK, but the fact remains that treatment options are limited. Hopefully this will help change that.” SMT