Factors Affecting Dimensional Precision of Consumer 3D Printing

International Journal of Aviation, Aeronautics, and Aerospace Volume 2 Issue 4 Article 2 9-21-2015 Factors Affecting Dimensional Precision of Consumer 3D Printing David D. Hernandez Embry-Riddle Aeronautical University, Follow this and additional works at: https://commons.erau.edu/ijaaa Part of the Applied Mathematics Commons, Design of Experiments and Sample Surveys Commons, Engineering Commons, Entrepreneurial and Small Business Operations Commons, and the Technology and Innovation Commons Scholarly Commons Citation Hernandez, D. D. (2015). Factors Affecting Dimensional Precision of Consumer 3D Printing. International Journal of Aviation, Aeronautics, and Aerospace, 2(4). https://doi.org/10.15394/ijaaa.2015.1085 This Article is brought to you for free and open access by the Journals at Scholarly Commons. It has been accepted for inclusion in International Journal of Aviation, Aeronautics, and Aerospace by an authorized administrator of Scholarly Commons. For more information, please contact . Hernandez: Dimensional Precision 3D Printing 3D printing has been gaining more widespread usage, with falling prices and operational simplicity bringing the tool out of the realm of corporations and into the hands of individuals. Indeed, the techniques comprising today’s rapid prototyping – creating full-scale models that reproduce the size, shape, and functionality of conventionally manufactured items – have made it possible for individuals to create new products in shorter timeframes than whole corporations could just a few short years ago. Roland DGA Corporation (2011) cites two major shifts in how products are developed – an economic shift caused by rising costs associated with outsourced manufacturing and an increase in entrepreneurship, respectively – which are pushing towards a business model where conceptualization and productization are co-located. Three-dimensional Computer-Aided Design (CAD) data and 3D scanning technology have both been made available and refined through open-source communities, in addition to the availability of their for-profit counterparts. The 3D printer forms the final component in a chain which turns ideas and intellectual property into tangible product. Rapid prototyping expedites the typical manufacturing process through the use of both subtractive and additive technologies, as opposed to wholesale creation of customized tooling – the traditional approach (CustomPartNet, 2009). A subtractive technology, such as CNC milling, uses digital data to transform raw material by removing material in a predetermined fashion. By skipping the step of creating typical manufacturing tooling, the same rapid processes, techniques, and tools can be used to manufacture a wide-range of devices more quickly. The most ubiquitous and economical consumer 3D printing devices make use of additive technology – fused deposition modeling (FDM). FDM builds up a physical model layer-by-layer, fusing higher layers of material to the layers beneath them to create new objects (Akande, 2015). Though the march towards increasingly capable consumer printing has been steady, it is important Published by Scholarly Commons, 2015 1 International Journal of Aviation, Aeronautics, and Aerospace, Vol. 2 [2015], Iss. 4, Art. 2 to note that economical 3D printing devices have not yet achieved a level of simplicity and reliability comparable to that of the typical consumer devices that have achieved mass adoption. In order to provide a quantitative analysis of this reliability, the study described in this paper focused on dimensional precision of a consumer-grade, FDM printer. A full factorial design of experiments (DOE) analysis was conducted, resulting in an Analysis of Variance (ANOVA) design that shed light on the various factors that affect the use of FDM, in terms of dimensional precision. The goal was to evaluate the limitations of the technology, to rule out factors that do not contribute in a statistically significant fashion to print precision, and to provide a practical, quantitative guide for optimizing results of consumer grade 3D printing for application as an engineering tool. Finite Deposition Modeling – An Emerging Technology FDM raw material may consist of a variety of substances – often thermoplastics or thermoplastics infused with other materials. The most common materials used for FDM are Acrylonitrile butadiene styrene (ABS) and Polylactide (PLA), with their characteristics of becoming a liquid substance with predictable flow properties in response to heat, while forming a reliable solid once cooled (Liing Shian Colorant Manufacturer Co., Ltd., 2013). This process of heating and cooling plastic, with some well-modeled aspects, is still susceptible to random variation, with unpredictable results depending on the shape being printed. Differences in material properties across manufacturers and even across different material lots from the same manufacturer can result in very different printing results, requiring user intervention to refine several printer parameters until usable prints are achieved (Boots Industries, n.d.). These include extrusion rate, nozzle temperature, bed temperature and the properties of the design, itself. Several papers in the public literature (e.g., Bakar, Alkahari, & Boejang, 2010; Luzanin, Movrin, & https://commons.erau.edu/ijaaa/vol2/iss4/2 DOI: https://doi.org/10.15394/ijaaa.2015.1085 2 Hernandez: Dimensional Precision 3D Printing Plancak, 2013; Udroiu & Mihail, 2009) have attempted to quantify the effects of various usercontrollable factors on print quality. In at least one case (Luzanin, 2013), the investigators were required to change their experimental plan when the printer was found to be incapable of printing adequate test articles. The focus of this paper is on the use of consumer-grade 3D printing to create engineering prototypes of, tooling for, or finalized instances of mechanical devices. Unlike aesthetic uses of FDM, a focus on accuracy - ability to meet precise physical dimensions, consistent shapes, and predictable surface finish - is important in the case of engineered mechanical devices. 3D printing, because of its additive nature, provides a capability to create unique components that cannot be replicated via subtractive techniques. Consumer grade printing provides advantages in both expense and turnaround time that represent a significant change in how certain engineering challenges may be addressed. The measurement of fluid flow, for example, necessitates very precise control of dimensioned parts with specific characteristics (The American Society of Mechanical Engineers, 2004), which works counter to the concept of physical experimentation. The approach of using changeable, disposable components in order to iterate towards an optimal combination of test parameters, has previously been impractical. 3D printing could, among other uses, provide a way to fabricate customized fluid flow test components (...truncated)