15 Takeaways on Additive Manufacturing

A Modern Casting Staff Report

The metalcasting industry knows the importance of being at the cutting edge of technology. That, again, was proven true during the 2018 Additive Manufacturing for Metalcasting Conference.

From Sept. 10-13 in Louisville, Kentucky, over 120 attendees heard about the latest developments in this new and crucial process. They heard informative presentations and went on a tour of the University of Louisville’s Rapid Prototyping Center.

“The event that we’re having for additive manufacturing is pivotal in this industry,” said Brandon Lamoncha of AFS Corporate Member Humtown Products (Columbiana, Ohio). “I’m getting more and more requests from OEMs that want to use foundries that have additive capabilities – whether that means they have their own printers or [are] utilizing service centers.”

During his keynote presentation, Ron Walling of AFS Corporate Member Cummins (Columbus, Indiana) stressed that foundries need to educate themselves on the process, while additive companies should drive for cost competitiveness in comparison to conventional processes.

 “I just think it’s important to get the information of additive manufacturing and other topics out there, and to really provide a lot of interaction between people and an exchange of ideas,” Walling said.

During his presentation, Walling made one thing clear: additive manufacturing technology is here today.

Here are 15 takeaways from presentations delivered at the event. They are relevant to metalcasters and suppliers.

1. Additive manufacturing can be adopted in production foundries.
Foundries can educate themselves on printed sand technology and utilize the existing printed sand supply base for initial implementation. They should also develop engineering skills for process development with printed sand.

2. Lowering additive manufacturing costs is possible.
When a company wants to achieve lower costs, a focus should be on the total process–from raw material to the finished mold, which reduces material waste in the process. A reduction of post-processing work, along with an effort to expand and improve the sand printing product line and add more binders and aggregates, is also key.

3. Barriers to designing for printed sand still exist.
Design rules for castings produced in additive sand molds are not fully understood. Achieving product value that exceeds added cost is still part of the basic equation.

4. Additive sand isn’t always the right solution
While additive sand technology continues to emerge, it does have some drawbacks. It is slow for ongoing production, the per-piece cost is high, there’s a limited supply base, and it’s still new and somewhat unfamiliar.

5. Printed wax patterns are viable for low-to-medium volume production.
The cost break-even is about 300 patterns for pattern volumes less than 3 cubic inches when comparing molded to printed. Higher tooling cost increases the break-even point.
—Sharon Weaver, 3D Systems; Tom Mueller, AMS

6. Printed patterns have many additional benefits.
They provide a faster delivery of initial castings, painless design changes and no tooling storage costs for printed patters. Printed patterns also can lead to new business opportunities via unmoldable designs.
—Weaver, Mueller

7. A patternmaker’s path has fewer steps today.
Twenty years ago, a patternmaker would have a lengthy path of production to produce a prototype V-8 engine block: create models of cores, create prints for package, design tooling, manufacture tooling, add gating to tooling, send tooling to the foundry to make cores, then the foundry assembles and casts, then analyzes the casting and develops improvements, casts again, and repeats final steps until casting is correct. Currently, a patternmaker would have a shorter path of production to produce a prototype V-8 engine block. The process begins with simulation, moves to gating and package design, then the 3D sand package is printed, with the foundry assembling and casting the component.
—Ted Kahaian, Tooling & Equipment Interntional

8. 3D printed ceramics are promising but aren’t always a fit.
Judicious application of 3D-printed ceramics for patterns, cores or molds for the right niche at the right point in the product lifecycle is key. Opportunities will continue to expand as the capability continues to mature.
—Robert Morris, Renaissance Services Inc.

9. Gaps exist in establishing standards.
It is imperative for the industry and associations to create standards for additive manufacturing when it comes to metalcasting. Supporting projects and studies that validate additive manufacturing-related processes and equipment is important, as is funding best practices.
—Sheku Kamara, Milwaukee School of Engineering

10. Printed gating can be feasible for automated molding machines, and printed patterns can bring similar results.
In one case study, a company saw up to a 20% cost reduction with printed gating. The process also shortened the company’s lead time. The same company printed patterns for a customer, and the results were similar, providing a lower tooling cost, fewer process steps, and shorter lead times.
—Garrett Iverson, Scenic Industries

11. A pattern/tooling shop can enjoy many important benefits.
Printing frees up assets to take on more jobs better suited for subtractive manufacturing. Printing time doesn’t equal operator time. One person can operate and manage a network of printers.

12. Printed sand aggregates have requirements.
A printed sand aggregate needs flowability, non-clumping, and uniform spreading, and cannot push during recoating. Printed sand must function within the target
layer thickness.
—Kip Woods, Emerson Automation Solutions; Scott Giese, University of Northern Iowa; Sudhir Trikha, H.A. International

13. Printed sand resin systems also have requirements.
A printed sand resin system needs sustainable jetting without nozzle loss, no adverse printhead degradation, precise printing resolution, acceptable tensile and transverse strength, and acceptable loss on ignition value.
—Woods, Giese, Trikha

14. Education is key.
Many avenues are available for facilities looking to learn about additive and what it can offer. The AFS Additive Manufacturing Division has resources ready, and there are conferences and presentations on offer.

15. Additive companies can help spur growth.
Companies that supply additive manufacturing technology can do undertake some initiatives to make the process more mainstream. They can drive for cost competitiveness in comparison to conventional processes, add flexibility where it’s possible, and develop more machines for the production environment.

Click here to see this story as it appears in the November 2018 issue of Modern Casting