ADDITIVE MANUFACTURING is the magazine devoted to industrial applications of 3D printing and digital layering technology. We cover the promise and the challenges of this technology for making functional tooling and end-use production parts.
Issue link: https://am.epubxp.com/i/894355
NOVEMBER 2017 Additive Manufacturing FEATURE / AM for Metal Casting 54 we needed to get this process in-house." HCC purchased the Viridis machine in November of 2016. After the head of technical operations at EnvisionTec, the parent company of Viridis3D, oversaw installation of the sand printing system at HCC the following month, its first com- mercial print was for a pump company that contracted a small production run of five pieces. HCC was the first foundry in the country to purchase the RAM123 model, and its first job gave Badamo and his team a chance to experiment and become famil- iar with the system's capabilities. Subsequent jobs have revealed efficiencies and hybrid applications with traditional foundry methods that have presented the HCC team with an interesting dilemma: which competitive advantage to exploit first. all with complex geometries normally requiring patterns and/or core boxes that would have been difficult to build. 3D printing allows HCC to forgo this tooling in order to let the customer test and potentially change the design. Hybrid Casting By printing molds and cores straight from CAD from the sand printing system, Hazleton can offer customers a production timeline of three to four weeks for a prototype or final part, rather than the three to four months typically required when patternmaking and core box machining are part of the process. Hazleton Casting is a sister facility to the much larger Weatherly Casting & Machine Company. Primarily an iron foundry located just nine miles from Hazleton, Weatherly's melt capacities are greater than Hazleton's. Weatherly can combine melt capacities to 20,000 pounds, while HCC can achieve a com- bined 12,000-pound pour. But with the introduction of additive manufacturing, the two foundries are able to partner in ways that were unprecedented before the arrival of AM at Hazleton. At the time of my visit to Hazleton this past June, HCC was under contract to create mill liners for a power- generating company that lacked original patterns. Given the company's short lead time, Badamo quoted the job through the 3D printer, which can create molds for casting not only for HCC but also for Weatherly's much larger facility. By compressing the lead time, Hazleton was able to sell speed in a way it previously could not. "It was a lead-time-specific decision," Badamo says. "The cost is higher with the 3D-printed product, but when you add the cost of the tool, plus the cost of the part, plus the loss of production in the lead time, it's an economic opportunity." But the choice isn't either-or. Significantly, Hazleton has also learned to integrate 3D printing with its traditional foundry operations into a hybrid casting process. Using conventional tooling—a pattern—Hazleton can create a base form for a given part. Then, it can use 3D printing just for design configurational changes within the mold. For instance, during my visit, HCC was in the process of building stem patterns for a valve man- ufacturer, and it reduced costs by 3D printing the cores. Since Full view of the 3D printing sand mold operation at Hazleton Cast- ing. Each pass of the print head deposits a new layer of sand as well as a binder to create the mold or core. Since much of Hazleton's value is derived from the ability to perform small-capacity, engineered-to-order short produc- tion runs, sometimes in expensive metals, the opportunity to assist customers with product development is one of the major advantages of using sand printing as an alternative to conven- tional foundry tooling. For instance, HCC has contracted with a company that wants to test four design configurations for four different parts. Do the math, and that's 16 unique castings,