Gerald C. Anzalone

Open-Source Colorimeter

The high cost of what have historically been sophisticated research-related sensors and tools has limited their adoption to a relatively small group of well-funded researchers. This paper provides a methodology for applying an open-source approach to design and development of a colorimeter. A 3-D printable, open-source colorimeter utilizing only open-source hardware and software solutions and readily available discrete components is discussed and its performance compared to a commercial portable colorimeter. Performance is evaluated with commercial vials prepared for the closed reflux chemical oxygen demand (COD) method. This approach reduced the cost of reliable closed reflux COD by two orders of magnitude making it an economic alternative for the vast majority of potential users. The open-source colorimeter demonstrated good reproducibility and serves as a platform for further development and derivation of the design for other, similar purposes such as nephelometry. This approach promises unprecedented access to sophisticated instrumentation based on low-cost sensors by those most in need of it, under-developed and developing world laboratories.

Open-Source Syringe Pump Library

This article explores a new open-source method for developing and manufacturing high-quality scientific equipment suitable for use in virtually any laboratory. A syringe pump was designed using freely available open-source computer aided design (CAD) software and manufactured using an open-source RepRap 3-D printer and readily available parts. The design, bill of materials and assembly instructions are globally available to anyone wishing to use them. Details are provided covering the use of the CAD software and the RepRap 3-D printer. The use of an open-source Rasberry Pi computer as a wireless control device is also illustrated. Performance of the syringe pump was assessed and the methods used for assessment are detailed. The cost of the entire system, including the controller and web-based control interface, is on the order of 5% or less than one would expect to pay for a commercial syringe pump having similar performance. The design should suit the needs of a given research activity requiring a syringe pump including carefully controlled dosing of reagents, pharmaceuticals, and delivery of viscous 3-D printer media among other applications.

A Low-Cost Open-Source Metal 3-D Printer

Technical progress in the open-source self replicating rapid prototyper (RepRap) community has enabled a distributed form of additive manufacturing to expand rapidly using polymer-based materials. However, the lack of an open-source metal alternative and the high capital costs and slow throughput of proprietary commercialized metal 3-D printers has severely restricted their deployment. The applications of commercialized metal 3-D printers are limited to only rapid prototyping and expensive finished products. This severely restricts the access of the technology for small and medium enterprises, the developing world and for use in laboratories. This paper reports on the development of a open-source metal 3-D printer. The metal 3-D printer is controlled with an open-source micro-controller and is a combination of a low-cost commercial gas-metal arc welder and a derivative of the Rostock, a deltabot RepRap. The bill of materials, electrical and mechanical design schematics, and basic construction and operating procedures are provided. A preliminary technical analysis of the properties of the 3-D printer and the resultant steel products are performed. The results of printing customized functional metal parts are discussed and conclusions are drawn about the potential for the technology and the future work necessary for the mass distribution of this technology.

Open-source 3-D printing technologies for education

Objective3-D printing technologies have the potential to improve both Science, Technology, Engineering, and Mathematics (STEM) education and Career and Technical Education (CTE), as well as integrating these two educational emphases and providing opportunities for cross-curriculum engagement. The objective of this study is to investigate the potential of open-source (OS) technologies in an educational setting, given the combination of economic constraints affecting all educational environments and the ability of OS design to profoundly decrease the cost of technological tools and technological innovation. MethodsThis paper reports on a 3-day workshop augmented with online instructional and visual tools designed for middle school and high school level educators from a wide array of disciplines (including traditional science, math, and engineering as well as computer, shop, and art). Teachers (n=22) submitted applications to participate in the workshop, the workshop was observed for both evaluation and research, teachers participated in focus groups (n=2) during the workshop in order to discuss their interest in OS 3-D printing technology and its potential role in their classrooms, and teachers completed a voluntary post-workshop survey and responded to follow-up after printers were in the classroom for one year. ResultsDuring the workshop teachers built 3-D printers using OS technologies that they were then able to take back to their schools and into their classrooms. ConclusionThrough workshops augmented with online instructional and visual tools designed to provide facilitated yet self-directed engagement with a new, relatively unknown, and relatively complex technology, paired teacher teams were able to successfully build and use RepRap 3-D printers based on OS design in just three days. PracticeHere, we discuss both what the teachers learned and what we learned from the teachers regarding the potential for educators to construct OS 3-D printing technologies as a tool of empowering and transformative education. ImplicationsOpen-source 3-D printing technologies have the potential to improve education through a sense of empowerment resulting from active participation, as well as through cross-curriculum engagement. Display Omitted Open-source 3D printing provides a cost efficient means of STEM education.These technologies can also empower student-driven engaged learning.Report on workshop for science educators to build 3D printers for their classes.Teacher workshop augmented with online instructional and visual tools.Results indicate transformative potential of these technologies in the classroom.

Low-Cost Open-Source Voltage and Current Monitor for Gas Metal Arc Weld 3D Printing

Arduino open-source microcontrollers are well known in sensor applications for scientific equipment and for controlling RepRap 3D printers. Recently low-cost open-source gas metal arc weld (GMAW) RepRap 3D printers have been developed. The entry-level welders used have minimal controls and therefore lack any real-time measurement of welder voltage or current. The preliminary work on process optimization of GMAW 3D printers requires a low-cost sensor and data logger system to measure welder current and voltage. This paper reports on the development of a low-cost open-source power measurement sensor system based on Arduino architecture. The sensor system was designed, built, and tested with two entry-level MIG welders. The full bill of materials and open source designs are provided. Voltage and current were measured while making stepwise adjustments to the manual voltage setting on the welder. Three conditions were tested while welding with steel and aluminum wire on steel substrates to assess the role of electrode material, shield gas, and welding velocity. The results showed that the open source sensor circuit performed as designed and could be constructed for <

Robust Test of the Flatbed Scanner for Air-Void Characterization in Hardened Concrete

100 in components representing a significant potential value through lateral scaling and replication in the 3D printing community.

Field Study of Air Content Stability in the Slipform Paving Process

In the province of Ontario, Canada, the Ministry of Transportation administers a quality assurance testing program for all new concrete construction where air content and spacing factor are measured. Testing is performed by qualified operators in accordance with ASTM C457/C457M-12. In this study, 324 routine samples that had been tested by qualified operators were obtained and analyzed for air-void parameters by an alternative automated flatbed scanner method. A strong correlation was found between the manual and automated methods. This research explored the premise that summary statistics from a small set of training samples could be used to define a set of global threshold levels to measure air-void parameters from a much larger population. Two different methods for setting the global thresholds were tested: one based on arithmetic means, and another based on modal location parameters derived from type I extreme value distributions. The frequency of false-negative errors (failure to detect a defect) was used as a criterion to assess the different threshold methods. Automated test results derived using global thresholds based on arithmetic means minimized the occurrence of false-negative events.

Life-cycle economic analysis of distributed manufacturing with open-source 3-D printers

This study evaluated the impacts of construction on the air content and air void system structure of portland cement concrete pavements. The primary intent was to quantify the air content of fresh concrete before and after it had gone through the slipform paver. The air void system parameters of hardened concrete were then assessed with cast cylinders and extracted core specimens. The results of the air content testing on fresh concrete and the concrete cylinder specimens cast in the field suggested that some loss of air (approximately 1%) occurred as the concrete passed through the paver. Laboratory testing performed on cores extracted from the pavement did not provide conclusive evidence that entrained air was lost during the slipform paving process. In fact, many extracted cores had measured air content values that were much higher than those measured in the fresh concrete and even higher than the specification requirement. If excessive, such values could result in increased permeability and low-strength-related issues. The results suggested that the air content testing on fresh concrete did not capture the true air content of the concrete as it was placed with a slipform paver. The fresh concrete air content in general was lower than was the air content measured in the cores.