LOW-COST OPEN-SOURCE GMAW-BASED METAL 3-D PRINTING: MONITORING, SLICER, OPTIMIZATION, AND APPLICATIONS

Low-cost and open-source gas metal arc welding (GMAW)-based 3-D printing has been demonstrated yet the electrical design and software was not developed enough to enable wide-spread adoption. This thesis provides three novel technical improvements based on the application of mechatronic and software theory that when combined demonstrate the ability for distributed digital manufacturing at the small and medium enterprise scale of steel and aluminum parts. First, low cost metal inert gas welders contain no power monitoring needed to tune GMAW 3-D printers. To obtain this data about power and energy usage during the printing, an integrated monitoring system was developed to measure current (I) and voltage (V) in real-time. The new design of this monitoring system integrates an open source microcontroller and free and open source software on the open-source metal 3-D printer to record the data. Second, the primary obstacle to the diffusion of this technology was that existing slicing software, which determines the toolpath of the printhead was optimized for polymer 3-D printing and inappropriate for printed parts made from metal due to their mechanical strength. Previous prints were accomplished by manually designing the toolpath, which was not practical for real use by an extended userbase. To overcome the problem, the free and open-source slicing software, CuraEngine, was forked to MOSTMetalCura, which supports the needs of GMAW-based metal 3-D printing. The optimized setting for wire feed rate is calculated by the new slicer based on printing speed, bead width, layer height, and material diameter. Previous studies have shown that GMAW-based metal 3-D printing is capable of fabricating parts with good layer adhesion and porosity. However, this preliminary work lacked demonstrations of real-world applications. Finally, in this work, the practical applications of open-source GMAW-based metal 3-D printing are well demonstrated for both developing world and developed world applications including: 1) fixing an existing part by adding on a 3-D metal feature, 2) creating a product using the substrate as part of the component, 3) 3-D printing useful objects in high resolution, 4) near net shape objects and 5) making an integrated product using a combination of steel and polymer 3-D printing. The results prove that low-cost and open-source GMAW-based metal 3-D printing is ready for distributed manufacturing by SMEs and adequate for a wide range of applications

Free and Open Source 3-D Model Customizer for Websites to Democratize Design with OpenSCAD

International audience3-D printing has entered the consumer market because of recent radical price declines. Consumers can save substantial money by offsetting purchases with DIY pre-designed 3-D printed products. However, even more value can be obtained with distributed manufacturing using mass customization. Unfortunately, the average consumer is not technically sophisticated enough to easily design their own products. One solution to this is the use of an overlay on OpenSCAD parametric code, although current solutions force users to relinquish all rights to their own designs. There is thus a substantial need in the open source design community for a libre 3-D model customizer, which can be used in any design repository to democratize design. This study reports on the design, function, and validation of such software: the Free Open Source 3-D Customizer. It is demonstrated with a case study of the customization of 3-D printable external breast prosthetics. The results showed that novice users can adjust the available parameters according to their needs and save these to a new file on a website. This PHP (recursive acronym for PHP: Hypertext Preprocessor) library is free and open source and has potential for increasing the usefulness of online repositories to enable distributed manufacturing using consumer customized 3-D printable products

Integrated voltage—current monitoring and control of gas metal arc weld magnetic ball-jointed open source 3-D printer

To provide process optimization of metal fabricating self-replicating rapid prototyper (RepRap) 3-D printers requires a low-cost sensor and data logger system to measure current (I) and voltage (V) of the gas metal arc welders (GMAW). This paper builds on previous open-source hardware development to provide a real-time measurement of welder I-V where the measuring circuit is connected to two analog inputs of the Arduino that is used to control the 3-D printer itself. Franklin firmware accessed through a web interface that is used to control the printer allows storing the measured values and downloading those stored readings to the user’s computer. To test this custom current and voltage monitoring device this study reports on its use on an upgraded all metal RepRap during the printing of aluminum alloy (ER1100, ER4043, ER4943, ER4047, and ER5356). The voltage and current data were analyzed on a per alloy basis and also layer-by-layer in order to evaluate the device’s efficacy as a monitoring device for 3-D printing and the results of the integrated design are discussed

Free and Open Source 3-D Model Customizer for Websites to Democratize Design with OpenSCAD

3-D printing has entered the consumer market because of recent radical price declines. Consumers can save substantial money by offsetting purchases with DIY pre-designed 3-D printed products. However, even more value can be obtained with distributed manufacturing using mass customization. Unfortunately, the average consumer is not technically sophisticated enough to easily design their own products. One solution to this is the use of an overlay on OpenSCAD parametric code, although current solutions force users to relinquish all rights to their own designs. There is thus a substantial need in the open source design community for a libre 3-D model customizer, which can be used in any design repository to democratize design. This study reports on the design, function, and validation of such software: the Free Open Source 3-D Customizer. It is demonstrated with a case study of the customization of 3-D printable external breast prosthetics. The results showed that novice users can adjust the available parameters according to their needs and save these to a new file on a website. This PHP (recursive acronym for PHP: Hypertext Preprocessor) library is free and open source and has potential for increasing the usefulness of online repositories to enable distributed manufacturing using consumer customized 3-D printable products

Free and open source 3-d model customizer for websites to democratize design with openscad

3-D printing has entered the consumer market because of recent radical price declines. Consumers can save substantial money by offsetting purchases with DIY pre-designed 3-D printed products. However, even more value can be obtained with distributed manufacturing using mass customization. Unfortunately, the average consumer is not technically sophisticated enough to easily design their own products. One solution to this is the use of an overlay on OpenSCAD parametric code, although current solutions force users to relinquish all rights to their own designs. There is thus a substantial need in the open source design community for a libre 3-D model customizer, which can be used in any design repository to democratize design. This study reports on the design, function, and validation of such software: the Free Open Source 3-D Customizer. It is demonstrated with a case study of the customization of 3-D printable external breast prosthetics. The results showed that novice users can adjust the available parameters according to their needs and save these to a new file on a website. This PHP (recursive acronym for PHP: Hypertext Preprocessor) library is free and open source and has potential for increasing the usefulness of online repositories to enable distributed manufacturing using consumer customized 3-D printable products

Open source database and website to provide free and open access to inactive U.S. patents in the public domain

Although theoretically the patent system is meant to bolster innovation, the current United States Patent and Trademark Office (USPTO) is cumbersome and involves a significant time investment to locate inactive patents less than 20 years old. This article reports on the development of an open source database to find these public domain ideas. First, a search strategy is explained. Then the operation and use of free and open source software are detailed to meet the needs of open hardware innovators. Finally, a case study is presented to demonstrate the utility of the approach with 3-D printing. The results showed how the Free Inactive Patent Search enables users to search using plain language text to find public domain concepts and then provides a hyperlinked list of ideas that takes users to the USPTO database for the patent for more information. All of the source code to operate the search and the website are open source themselves and provided in the public domain for free. In the case study on 3-D printing the time to identify public domain patents was cut by a factor of more than 1500. This tool has the potential for accelerating the development of open hardware technologies to create high value for the public

Slicer and process improvements for open-source GMAW-based metal 3-D printing

Low-cost gas metal arc welding (GMAW)-based 3-D printing has proven effective at additive manufacturing steel and aluminum parts. Early success, however, was based on hand-writing G-code, which is inadequate for the majority of potential users. To enable automated slicing a 3-D model and generating G-code for an acceptable path for GMAW 3-D printing, this paper reports on upgrading of the free and open source CuraEngine. The new slicer, MOSTMetalCura, provides the following novel abilities necessary for GMAW 3-D printing: i) change the perimeter metric from width to track count, ii) avoid movement that overlaps previous weld beads, iii) have infill start immediately after the perimeter finished and in the direction that eliminates translations, iv) add a variable pause between layers to allow for substrate cooling, v) configure GPIO pins to turn on/off the welder, and vi) set optimized wire feed speed and voltage of the welder based on printing speed, layer height, filament diameter, and tool track width. The process for initiating these changes are detailed and the new slicer is used to help improve the function of the printer for ER70S-6 steel. To find the printing function with the smallest bead width based on volume of material, the line width, layer height, and printing speed are varied to provide wire feed speed calculated by MOSTMetalCura, then the settings are used to print 3-D models. The results of 3-D printing three case study objects of increasing geometric complexity using the process methodology improvements presented, which show resolution of 1 mm bead widths

A review of technical requirements for plug-and-play solar photovoltaic microinverter systems in the United States

The average American is highly supportive of solar photovoltaic (PV) technology and has the opportunity to earn a high return of investment from a PV investment for their own home. Unfortunately, the average American does not have easy access to capital/financing to install a PV system able to meet their aggregate annual electric needs. One method to overcome this challenge is to allow \u27plug-and-play solar\u27, which is defined as a fully inclusive, commercial, off-the-shelf PV system (normally consisting of a PV module and microinverter), which a prosumer can install by plugging it into an electric outlet and avoiding the need for significant permitting, inspection and interconnection processes. Many advanced countries already allow plug-and-play solar, yet U.S. regulations have lagged behind. In order to assist the U.S. overcome regulatory obstructions to greater PV penetration, this article first reviews the relevant codes and standards from the National Electric Code, local jurisdictions and utilities for PV with a specific focus on plug-and-play solar. Next, commercially available microinverters and alternating current (AC) modules are reviewed for their technical and safety compliance to these standards and all were found to be compliant. The technical requirements are then compared to regulatory and utility requirements using case studies in Michigan, which were found to create arbitrary non-technically-valid barriers to grid entry. The analysis also exposed the redundancy of the utility accessed AC disconnect switch for residential and small commercial grid connected solar PV. It is clear that the AC disconnect switch is not necessary technically and thus imposing it is an economic barrier to grid entry for solar PV systems with UL (Underwriters Laboratories) certified microinverters. To reduce consumer and utility workload and the concomitant soft costs, this article provides a streamlined application with only technical requirements and free and open source software to ease utility implementation. Finally, the advantages of supporting plug-and-play solar PV with UL certified microinverters include greater PV system performance, faster uptake and higher PV penetration levels, improved prosumer economics, and more environmentally responsible electric generation

Applications of open source gmaw-based metal 3-d printing

The metal 3-D printing market is currently dominated by high-end applications, which make it inaccessible for small and medium enterprises, fab labs, and individual makers who are interested in the ability to prototype and additively manufacture final products in metal. Recent progress led to low-cost open-source metal 3-D printers using a gas metal arc welding (GMAW)-based print head. This reduced the cost of metal 3-D printers into the range of desktop prosumer polymer 3-D printers. Consequent research established good material properties of metal 3-D printed parts with readily-available weld filler wire, reusable substrates, thermal and stress properties, toolpath planning, bead-width control, mechanical properties, and support for overhangs. These previous works showed that GMAW-based metal 3-D printing has a good adhesion between layers and is not porous inside the printed parts, but they did not proceed far enough to demonstrate applications. In this study, the utility of the GMAW approach to 3-D printing is investigated using a low-cost open-source metal 3-D printer and a converted Computer Numerical Control router machine to make useful parts over a range of applications including: fixing an existing part by adding a 3-D metal feature, creating a product using the substrate as part of the component, 3-D printing in high resolution of useful objects, near net objects, and making an integrated product using a combination of steel and polymer 3-D printing. The results show that GMAW-based 3-D printing is capable of distributed manufacturing of useful products for a wide variety of applications for sustainable development

Real-Time Eye State Detection System for Driver Drowsiness Using Convolutional Neural Network

One of the top reasons for road accidents that result in injuries and deaths is the dozing off of drivers. In this study eye tracking using a novel open source Internet of Things (IoT)-based system has been developed. This study evaluated three driver\u27s eye recognition algorithms to be integrated into the open source solution to wake drivers as they begin to dose off: 1) Convolutional Neural Network (CNN) with Haar Cascade, 2) 68 facial landmark points and 3) gaze detection in three different face positions for both day and night driving conditions as well as with and without glasses. Each combination of those factor is tested 100 times. The best algorithm is chosen based on the numbers of correct detections and then this algorithm is tested again based on light (day and night), angle of face (left, right, and center), angle of camera (left and right), and glasses (on and off) to detect both blinking and closed eyes. The results show that the most accurate algorithm to detect a driver\u27s eyes is CNN with Haar Cascade algorithm with 94% accurate. The system can detect the status of the eyes of drivers during driving and if drivers close their eyes longer than two seconds, it sounds an alert to wake the driver and avoid the accident. The proposed open source system costs about US100 and could be widely deployed to help reduce accidents on the road throughout the world