Jyh Hwa Tzou

Desktop rapid prototyping system with supervisory control and monitoring through Internet

Rapid prototyping (RP) can enhance design and manufacturing productivity by taking advantage of the Internet. Via the Internet, most small and medium size companies should be able to share the access of the RP machine remotely without owning the expensive machines. This study combines RP preprocessing, RP machine, and the Internet into a telecontrolled manufacturing system. Also presented is the software and hardware for a new LCD-based photosensitive resin RP machine that uses only visible light. This visible light can expose and solidify an entire layer at once, layer-by-layer, until the whole part is finished. The user sends a three-dimensional (3-D) CAD model (STL file) via the Internet to a telecontrol server, which transforms the CAD model into a RP machine LCD photomask display. The user can then direct the RP machine to build the RP part while watching a live image of the part via the World Wide Web. An online visual system allows inspection of the RP part quality during manufacturing. Part building is monitored by a pattern matching algorithm which compares a grabbed image with the photomask. If the grabbed image is not adequately similar to the photomask, the program stops manufacture and notifies the user. The experimental results show that RP using the Internet is promised, but the surface roughness should be further improved.

The development of an intelligent Web-based rapid prototyping manufacturing system

A rapid prototyping (RP) machine system which combines a PC-based controller with the thermal-extrusion method is presented. The proposed RP system offers a three-axis platform, an extrusion head, a temperature controller, and a PC-based control system. Low-cost acrylonitrile-butadiene-styrene (ABS) pellets/powder are used for thermal extrusion, although the system is easily adapted to other not-too-dissimilar materials. In order to improve the quality of RP part, the Taguchi method was used to analyzing the process parameters of the proposed RP system. Based on the experimental results, the proposed RP mechatronics system can produce good quality RP parts. The RP software technique includes slicing, support, tool path, and motion code generation. This paper also presents a new adaptive slicing algorithm for RP system. According to this algorithm, the three-dimensional (3-D) computer-aided design (CAD) model can be sliced with different thickness automatically by comparing the contour circumference or the center of gravity of the contour with those of the adjacent layer. With this adaptive slicing method, the part can be fabricated faster than it uses uniform slicing method with identical accuracy. Finally, the intelligent web-based RP system allows remote users to upload an STL file, to directly building up of the physical model, and to monitor the actual fabrication process from a charged coupled devices (CCD) camera located in the RP machine itself. The user does not need to buy an expensive RP machine; instead, he can rent time and uses the machine remotely via the Internet.Note to Practitioners-RP has being used as an essential augmented tool between CAD and computer-aided manufacturing (CAM) for product manufacturing. RP uses layered manufacturing technology to produce complicated prototypes directly from a CAD model. As imaging, materials, and processing techniques improve, RP functions such as assembly fit, tooling masters, prototype tools, and prototype parts are made possible. RP technology that can construct parts of multiple materials, colors, and even parts composed of composite materials will soon be available. In this paper, an RP machine system which combines PC-based controller with thermal extrusion method is presented. Low-cost ABS pellets are used for thermal extrusion, although the system is easily adapted to other not-too-dissimilar materials. Based on the experimental results, the proposed RP mechatronics system can produce good quality RP parts. In this paper, a new adaptive slicing algorithm is developed to decrease fabrication time without much reducing the model accuracy. According to this algorithm, the 3-D CAD model can be sliced with different thickness automatically. With this adaptive slicing method, the part can be fabricated much faster than it uses traditional uniform slicing method. Finally, the intelligent web-based RP system has been developed which allows remote users to upload a CAD file of the part, direct building up of the physical model, and monitoring of the actual fabrication process from a CCD camera located in the RP machine itself. The greatest advantage is that user does not need to buy an expensive RP machine; instead he rents time and uses the machine remotely via the Internet. This really drastically reduces the production development cycle for the highly competitive time-to-market challenge.

The development of a new adaptive slicing algorithm for layered manufacturing system

Slicing process plays a very important role in layered manufacturing technology. A slicing algorithm decomposes the 3D CAD model into 2D layer contours that can be easily built. This paper presents a new adaptive slicing algorithm for a rapid prototyping system. According to this algorithm, the 3D CAD model can be sliced with different thickness automatically by comparing the contour circumference or the center of gravity of the contour with those of the adjacent layer. The part can be fabricated faster using this adaptive slicing method than using the uniform slicing method with identical accuracy. The proposed method was validated with computer simulation, and the part can be produced on the developed LCD panel display based rapid prototyping system.

The development of Internet accessible rapid prototyping system

Automated telecontrol of rapid prototyping machine via the Internet for the application of a telemanufacturing system is presented. The main features of this system are that users just need a general-purpose computer and a World Wide Web browser for commanding the rapid prototyping machine in a remote location through the Internet and a home page. Hardware configuration of this architecture includes a thermal extrusion based layer-deposition rapid prototyping machine and several controllers, each of them is able to communicate with others via computer network. Software design includes the user interface, model slicing process, model support generation, and tool path generation. The system has extensive capabilities for teleoperation and other multimedia services. The system allows users to directly control their rapid prototyping machine via the Internet and access their home page through a friendly user interface. Also the remote user can receive real time images e.g. the completed rapid prototyping model parts captured by a CCD camera that is mounted on the rapid prototyping machine.

Automated Desktop Manufacturing: Direct Metallic Rapid Tooling System

In recent years, Rapid Tooling (RT) has become more important because of the requirement of rapid manufacturing. RT can be used to produce temporary mold, even permanent mold in mass production. RT makes more benefit from design stage to mass production. The objective of this research is to develop the Direct Metallic Rapid Tooling System and identify process parameters of laser cladding. A metallic powder feeder system, a three-axis motion control system, a 500W Nd-YAG laser system, a shielding gas supply system, and a powder nozzle are incorporated for the hardware architecture in Direct Metallic Rapid Tooling System. Besides, the designed software that includes slicing algorithm with bucket sorting, contour generation and tool path generation algorithm are presented briefly. Effort was attempted to find out the better process parameters of laser cladding using single clad and cladding layer techniques. Based on the investigation, some metallic RT parts were fabricated and discussed.

Implementation of a new adaptive slicing algorithm for the rapid prototyping manufacturing system

Rapid prototyping is an automated manufacturing process that quickly builds physical models from three-dimensional (3-D) prototype computer-aided design files. It dramatically speeds up design and manufacturing processes and substantially reduces the cost. This paper presents a new adaptive slicing algorithm for rapid prototyping (RP) processes. The proposed adaptive slicing approach determines the layer thickness based on comparing the contour circumference or the center of gravity of the contour with those of the adjacent layer. Most commercial rapid prototyping systems use uniform slicing procedures with a fixed layer thickness to build parts. To implement the adaptive slicing algorithm, we developed a thermal extrusion based RP mechatronics system equipped with a linear planar servo motor. The RP material is wax. The XYZ table is controlled using a PC based multi-axis DSP motion controller. The RP material flow rate for the thermal extrusion head is controlled using a dc servo motor and motion controller. The Taguchi method was used to analyze the process parameters for the proposed RP system to improve the quality of the RP part. Based on the experimental results, the proposed RP mechatronics system can produce good quality RP parts with the adaptive slicing algorithm. The proposed RP system also implements the high-precision exterior, high-speed interior slicing strategy for STL models.

Investigation of a linear 2-D planar motor based rapid tooling system

Rapid prototyping (RP) has been widely known as being able to fabricate 3-D objects with complex geometric shapes. Rapid tooling has become more important because of the requirement of rapid manufacture. Rapid tooling can be used to produce a temporary mold, even a permanent mold in mass production. The objective of the paper is to develop a rapid tooling system. The software technique includes a slicing algorithm and tool path generation algorithm. The hardware architecture includes a 500 W Nd:YAG laser, metallic powder feeder, substrate preheat system, shielding gas (N/sub 2/) supply system, CNC milling system and linear planar motor based working table. The system controller is a PC-based control system which includes 4-axis DSP motion control and an I/O control card. The system control software is written in Visual Basic language. The experimental result shows that the linear 2-D planar motor based X-Y table has fast response and can make an accurate tool path.

The integration of 3D digitizing and LCD panel display based rapid prototyping system for manufacturing automation

3D digitization is the process of developing a CAD model and a manufacturing database from an existing part. This process is appealing because it could be difficult to create models of complex objects using CAD software without the aid of a 3D digitizer. The 3D CAD models that are generated from the scanned data can be edited and modified in the CAD system. The 3D model can also be put in multimedia or animation software as a learning or assembly aid. Rapid prototyping is widely known as being able to fabricate 3D objects with complex geometric shapes. Rapid prototyping can shorten the product development cycle and improve the design process by providing rapid and effective feedback to the designer, thus helping a company to keep ahead in a rapidly changing market. In the application of concurrent engineering and reverse engineering, the integration of 3D digitization and rapid prototyping can greatly shorten the product development cycle time. The 3D CAD model from the 3D digitizer can be modified by CAD software and the prototype can be manufactured using rapid prototyping to save lots of time and money. In a 3D digitizing system, we use a 3D laser scanner - Modelmaker - which combines a manually-operated arm with 6 degrees of freedom, a stripe 3D laser scanner and a contact probe. This fast and flexible 3D digitizer can produce complex models. By using post-processing software and a CAD system, an STL file can be produced, so we can produce a physical part by using the rapid prototyping system. In addition, this paper presents software and hardware technologies to build an LCD panel display-based rapid prototyping system. Software design for the system includes a slicing algorithm, LCD photomask display process, user interface and motion control program. The hardware configuration of the architecture includes an LCD photomask, optical system, z-axis elevator, resin supply system and PC-based control system.

Rapid tooling using laser powered direct metallic manufacturing process

Rapid tooling (RT) has recently become more important due to the requirement of rapid manufacturing in industrial automation field. RT can be used to produce temporary mold even permanent mold in mass production and to speed up compressed time into market. It makes more benefit from design stage to mass production. This study aims to develop the rapid tooling using laser powered direct metallic manufacturing process and identify process parameters of laser cladding. A metallic powder feeder system, a three-axis motion control system, a Nd:YAG laser system, a shielding gas supply system, and dual powder nozzle are integrated into the hardware architecture of laser powered direct metallic rapid tooling system. We attempt to find out the better process parameters of laser cladding by the Taguchis method. This system has been successfully demonstrated and some metallic RT molds and plastic injection molded part are fabricated through this proposed method.

The development of a direct metallic rapid prototyping system

Rapid tooling (RT) refers to the rapid creation of molds in much the same way as rapid prototyping, which means the rapid creation of models. Rapid prototyping is a method that offers both designers and manufacturers some advantages such as time compression and cost reduction. Rapid tooling has become more important because of the requirement of rapid manufacturing. Rapid tooling can be used to produce temporary mold, even permanent mold in mass production. Rapid tooling makes more benefit from design stage to mass production. The objective of This work is to develop a metallic rapid prototyping system and form a complete set of important parameters of laser cladding. The software technique includes slicing algorithm with bucket sorting and tool path generation algorithm. The hardware architecture includes 500 W Nd-YAG laser, metallic powder feeder, coaxial nozzle, shielding gas (Ar) supply system, CNC milling system and linear planar motor based working table. The system controller is a PC-based control system, which includes 3-axis AC servo motor driver and I/O control card. The system control software is written by Visual Basic language. The prototype system has been constructed and demonstrated.