Brett Conner

Quantifying the Role of Part Design Complexity in Using 3D Sand Printing for Molds and Cores

Abstract3D sand printing provides a means to fabricate molds and cores without the need to fabricate patterns and core boxes. It is desirable to understand when to use this evolving advanced technology versus conventional pattern making. This analysis evaluates this question by examining the cost of molds and cores as a function of part design complexity quantified by a complexity factor. Two case studies are presented where the complexity of the castings is systematically varied by changing the geometry and number of cores. Tooling costs and fabrication costs are estimated for both 3D sand printing and conventional pattern making. The breakeven points are identified, and it is shown that 3D sand printing is cost-effective for castings with complexity factor values greater than that of the breakeven points. For low volume production of these castings, 3D sand printing is shown to be cost-effective for low quantities (<45 parts) of castings with lower complexity. However, it can also be very cost-effective for casting with higher complexity even at quantities of 1000 units. Since breakeven point is sensitive to the cost of 3D sand printing, lowering the materials and operations costs can significantly improve the cost-effectiveness of 3D sand printing for varied production volume and part design complexity.

An assessment of implementation of entry-level 3D printers from the perspective of small businesses

Purpose – The purpose of this paper is to examine the implementation of entry-level printers in small businesses and education to identify corresponding benefits, implications and challenges. Design/methodology/approach – Data were collected from four small businesses in northeast Ohio through survey- and interview-based feedback to develop an understanding of their use of entry-level 3D printing. Three businesses are representative of typical manufacturing-related small companies (final part fabrication-, tooling- and system-level suppliers) and the fourth company provides manufacturing-related educational tools. Corresponding learning from implementation and outcomes are assessed. Findings – Adoption of 3D printing technology was enabled through hands-on experience with entry-level 3D printers, even with their shortcomings. Entry-level 3D printing provided a workforce development opportunity to prepare small businesses to eventually work with production grade systems. Originality/value – This paper deta...

3D Printed Smart Molds for Sand Casting

Additive manufacturing, also commonly referred to as 3D printing, stands to transform sand casting with binder jetting technology that can create sand molds with unmatched geometric complexity. With printed sand molds, castings can be optimized with regard to the strength-versus-weight trade-off and structures such as periodic lattices are now available within molds that are not possible with traditional casting technology. However, an increase in design complexity invites more challenges in terms of understanding and managing both the thermodynamics and physics of the casting process. Simulations of castings are more important than ever, and empirical in situ sensor data are required to validate high fidelity computer modeling (e.g., MAGMASOFT®). One novel solution is to leverage the design freedom of CAD-based solid modeling to introduce unique mold features specifically for housing sensors (Internet of Things) within the mold to enable the collection of a diversity of data at manifold locations: temperature, pressure, moisture, gas chemistries, motion of the molds and internal cores (shifting or rotation), and magnetic field. This report describes a proof of concept in which unprecedented levels of process monitoring were integrated—both wirelessly and wired—at strategic locations throughout a printed mold and inside of internal cores. The collected data were used to validate the quality of a casting in situ as well as to provide feedback for optimizing the casting process, mold design, and simulations. A trade-off was explored between sensor survivability and disposability.