Rapid Sheet Metal Manufacturing. Part 2: Direct Rapid Tooling

The traditional methods adopted for tool design and production in the sheet metal forming industry usually carry a high cost and long lead time resulting in cost justification problems for short production runs. Rapid tooling (RT) technology is capable of justifying the cost of tooling suitable for short production runs or design evaluation purposes. In Part 1 of this work, a new process termed rapid sheet metal manufacturing (RSMM) for the production of soft tooling suitable for prototyping, tool development, and short production runs was introduced. In addition, an indirect RT method employing rapid prototyping (RP), rapid soft tooling, and casting for the fabrication of non-ferrous tools was presented. The current work, Part 2, presents an alternative technique for RSMM whereby metal forming tools are fabricated directly from the RP system via selective laser sintering (SLS).     

Rapid Sheet Metal Manufacturing. Part 1: Indirect Rapid Tooling

Rapid sheet metal manufacturing (RSMM) is a closed loop process for making sheet metal products which uses advanced computer-aided techniques and computer-controlled machines to produce non-ferrous tooling directly or indirectly. The tooling would be suitable for short-run production or design evaluation of sheet metal products for which prototyping cost and lead time are greatly reduced. The key aspect of this closed-loop process is the method used to fabricate and modify the sheet metal forming tool. Various approaches are adopted in the preparation of the tooling for onward embossing on a sheet metal. The three indirect approaches use selective laser sintering (SLS), stereolithography (SLA), and high-speed computer numerical controlled (CNC) milling to build the masters from computer data models. The masters are used in the vacuum casting process to generate the non-ferrous tooling. Comparisons on quality, lead time and cost are presented.     

Rapid prototyping in the development of optical pickup unit

Rapid prototyping (RP) has already proven itself in the electronics industry as a method for shortening the product development time cycle. In the development of the optical pickup unit (OPU), extremely high precision is needed to make a functional model. Very often, in the design phase of the product development cycle, the prototype of the OPU is machined from a single piece of aluminium block to make the working sample. In this project, a comparison of the machined aluminium sample, RP samples from various RP processes and that moulded out from the injection moulding machine is made on surface finishing as well as dimensional accuracy. Finally, a comparison of tooling cost, piece part cost and lead time of obtaining the parts is also discussed on the different prototyping and manufacturing processes.     

Instant tools [rapid tooling]

Rapid prototyping (RP) technology has attracted a lot of attention as an effective tool to compress the new product development process and hence decrease the time to market. As RP technology continues to develop, other systems and processes, such as computer integrated manufacturing and metal injection moulding, are becoming available to industry. One such technology, driven by RP, is rapid tooling (RT) which has the potential to reduce product lead times. RT can be broken into two broad classifications: indirect and direct tooling. In producing a mould tool, for example, indirect tooling would use a master pattern, such as an RP model, to produce the mould cavity, whereas direct tooling would build the mould tool directly from CAD data. The paper reviews the prospects of creating a mould tool directly from a computer model     

Rapid tooling technology. Part 1. A comparative study

Rapid tooling (RT) is the technology that adopts rapid prototyping (RP) techniques and applies them to tool and die making. Research into RT techniques has shown that it is gaining more importance and is starting to pose a serious threat to conventional machining. In this paper, several popular RT techniques are discussed and then classified. A comparison is also made on these techniques based on tool life, tool development time and cost of tool development.     

快速制造模具技术

由新产品设计迅速形成高效、低成本、优质的批量生产并抢占市场，能否快速制模(RT)尤其是快速制造金属模具(RMT)是关键。RT技术在硅肢、树脂等软模快速制造方面已取得长足进步，目前正向快速制造金属硬模尤其是直接快速制造金属模具(DRMT)方向迅速发展。介绍了快速制模尤其是快速制造金属模具技术在材料、工艺、设备方面的研究进展，以及RMT技术与高速铣削技术(HSM)各自的优势，并探讨了与其竞争中面临的关键问题。     

快速模具系统工艺特点与分析

采用传统的模具加工方法,制造周期长且成本高。快速成型配合传统制模技术不仅适合单件小批的模具快速制造,而且能适应各种复杂程度的模具快速制造。介绍了基于快速成型技术的快速模具制造技术工艺原理、分类、成型方法及其技术特点以及与传统成形方式的区别。从模具的寿命,模具的制作成本,模具的生产周期等方面对几种典型快速模具制造技术系统进行了比较和归纳。分析了快速模具制造技术面临的关键问题,展望了基于快速成型原理的快速模具制造的应用前景。     

<Emphasis Type="Bold">A Rapid Manufacturing Method for Water-Saving Emitters for Crop Irrigation Based on Rapid Prototyping and Manufacturing</Emphasis>

In order to build the complex built-in labyrinth design of an emitter which is a key element in water-saving devices, rapid prototyping and manufacturing (RP&M) is used to design the emitters and to manufacture corresponding rapid tooling (RT). Detailed CAD design of the emitter, CAD process design, and the generation of RT process modelling of the emitter have been carried out using parameterised design. Prototypes have been built using RP techniques to perform the rapid verification and modification of the emitter design; rapid tooling (RT) for the emitter has been fabricated using a metal spraying process to carry out trial-production. Finally, with the fabrication ofa precision mould as the basis, emitter mould design and manufacturing have been completed. As a result, the integration of design/verification/manufacturing of a mould and its products is realised.     

快速模具技术在现代制造技术中的应用

快速模具技术随着工业化生产的发展而产生,一直受到模具界的广泛重视。文中概括地介绍了快速模具技术在现代制造技术中的应用,对于快速模具技术的应用与发展,具有重要的现实意义。     

快速成形转向快速生产的主要障碍

快速成形制造 (RPM)技术是国外 80年代后期发展起来的一门新兴综合技术。它使直接从概念设计迅速转为产品设计的生产模式成为可能 ,工业界正在探索使用快速成形机器生产最终要制造的零件的问题。但是 ,它面临诸如材料性能、表面质量、零件的尺寸规格和成形速度等许多挑战。一旦克服了这些障碍 ,快速成形就将转向快速生产 ,并将促进大量定制生产模式的加快实现     

Optimization of stereolithography process parameters for part strength using design of experiments

Rapid prototyping (RP) is an emerging technology that has been implemented in many spheres of industry – particularly in the area of new product development. Growth of this field has been rapid in recent years. Stereolithography (SL) is one of the most popular RP process used for rapid tooling applications. There are several process parameters contributing to the strength of an SL product. The contribution of three parameters; namely, layer thickness, post curing time and orientation are most significant. In light of this concern, an attempt has been made to study and optimize these process parameters for maximum part strength, and develop an empirical relationship between process parameters and part strength through design of experiments (DOE). The proposed DOE is verified with the data of experiments conducted under standard conditions.     

快速成形及其在快速制模中的应用

快速成形（ＲＰ＆Ｍ）作为一种新兴的先进制造技术,已成功地实现了快速原型制造,正向快速制模（ＲＴ）方向迅速发展。本文介绍了快速成形技术的现状及其在快速制模尤其是快速金属模具制造方面的应用,探讨了制约快速制模技术发展的关键问题和该技术的发展趋势。     

Implementation of rapid Prototyping technology — A Hong Kong manufacturing industry's perspective

Rapid Prototyping (RP) is a technology for rapid computerised building of 3D physical parts. It can be defined as an automated and patternless process which allows solid physical parts to be made directly from computer data in a short time. RP acts as the manufacturing middle to link up the computer-aided design (CAD) process and manufacturing processes. It includes the making of prototypes for design verification and even the making of tooling for production. With the trend towards concurrent engineering and the widespread use of CAD, RP has quickly become a booming business in the past few years. This paper presents an overview of the implementation of RP technology in Hong Kong and the critical decision factors in implementing RP in the Hong Kong manufacturing industry.     

快速模具技术在摩托车齿轮箱盖制造中的应用

介绍了将快速模具技术应用于摩托车齿轮箱盖零件制造的过程,研究了纸基砂型铸造模具制作的技术方案和实施步骤,并对其中的一些技术关键进行了深入的探讨.结果表明,利用快速模具技术可以取代传统的木模制作工艺,此技术具有制作周期短、成本低、尺寸精度高的特点,适用于产品开发过程中小批量样件的快速制造.     

基于数字制造模式的卫生洁具制造技术研究

介绍了基于CAD／CAE／CAM／RP技术的新的卫生洁具产品快速研发技术模式，即对产品进行参数化的计算机三维设计和产品物理性能的计算机模拟，然后采用快速原型技术，快速、准确地制出陶瓷种模，再翻制工作模。新方法不但提高了产品质量，而且可缩短新产品开发周期。     

基于Web的快速模具远程制造服务系统

数字化和网络化已成为当前制造业最为显著的生产特征。为了改变快速模具的传统制造模式为基于Internet的异地协同开发制造模式,解决逆向工程(RE)、快速成形(RP)、快速模具(RT)设备低利用率与企业得不到快速成形与制造(RP&M)技术服务的矛盾,缩短模具的生产制造周期,迎合新产品快速开发的需求。研究和开发了基于Web的快速模具远程制造服务系统。首先介绍了基于RE/计算机辅助设计(CAD)/RP快速模具开发制造系统的工作流程及其组成;然后阐述了远程制造服务系统的功能设计和关键技术的实现;最后构建了服务系统运行的Web平台。该系统旨在集成已有的RE、CAD、计算机辅助分析(CAE)、RP技术及以此为基础的快速模具制造技术,并以万维网(WWW)为支撑,以RP&M服务中心和各生产力促进中心为服务载体,以为远程用户、服务中心、协同制造企业提供方便快捷的技术信息平台、电子商务平台、制造服务平台为服务宗旨。     

Rapid Manufacture of Metal Tooling by Rapid Prototyping

As the race to launch a product successfully into the market increases in speed, the drive to reduce metal tooling lead time will become more important. Time reduction for fabricating metal tools depends on fast, efficient, and flexible manufacturing processes that dramatically reduce lead times while not sacrificing mechanical properties. A novel process of rapid tooling, non-baking of ceramic moulding, was studied. It uses a casting mould made from ceramic slurry and rapid prototyping to form a metal tool. It provides a quick, accurate, and relatively cost-effective route for producing metal parts or tools. The process and key technologies are analysed in detail. The process has been used in the automotive, consumer products, casting, and toy industries. Applications show that the total costs for new products can be reduced by as much as 40–60%, and lead times can be reduced by 50–60%. The surface roughness is approximately Ra = 3.2, and it can be improved to better that Ra = 1.6 by polishing. The dimensional accuracy relative to size is about ±0.1 mm for dimensions less than 200 mm. ID="A1"Correspondance and offprint requests to: Mr Z. Shan, The Centre for Laser Rapid Forming, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, PR China. E-mail: shanzhongde@mails.tsinghua.edu.cn     

3D printed tooling for vacuum-assisted resin transfer moulding

Three-dimensional printing (3DP) is widely considered to be one of the low-cost additive manufacturing (AM) processes. In this paper, the suitability of 3DP for making tooling for the vacuum-assisted resin transfer moulding (VARTM) process is considered. This combination has potential advantages, since VARTM has significant prototyping benefits if it can be combined with a fast and low cost tooling option. This paper presents a new process chain for the manufacture of closed mould composite parts using the VARTM process. It will be shown that 3DP tooling is significantly less accurate than CNC machined tooling, but there is a cost and time advantage to making tooling with 3DP. The mould life is also limited to typically 15 to 30 parts since significant wear occurs in the manufacturing process. Quantitative data are presented to show the effect of treating the mould surface to improve the surface roughness and to determine the mould life. An aspect often lacking in AM research is cost estimation. Here, the first cost model for rapid tooling for VARTM using 3DP moulds is presented and compared to actual results. It is shown that the model is suitable for design for manufacture analysis.     

MEM产品开发及工艺研究

介绍了如何应用MEM快速成型技术(属于RP技术的一种)进行产品开发,根据实际情况设计了实验方案,对支撑条件进行了详细的分析,通过实际加工,利用现有的MEM-300-1快速成型机设备,针对常用零件的通用特征,得到了在加工工艺过程中不加支撑或尽量减少支撑的条件:开放式悬臂长度L≤6mm、倾斜形特征倾斜角度θ≥30°、圆孔半径R≤4 mm、平顶长度M≤8 mm.     

Part Orientation in Stereolithography

Rapid prototyping (RP) machines reduce the lead time and cost of new products by automating the prototype manufacturing phase of the product development process. However, it is necessary for operators to orientate the prototype correctly in the RP machine to obtain the best trade-off between time, cost, and accuracy. The purpose of this work is to produce a decision-support tool to help RP users in this task. The tool is aimed at stereolithography which is the most widely adopted RP technology. The tool is a feature-based system produced using an object-orientated programming language and a solid modelling CAD environment. Cost, time, problematic features, optimally orientated features, overhanging area, and support volume are considered when recommending a build direction to the user. Three sample parts were used to illustrate the performance of the system. The system yielded the best surface finish and correctly highlighted several problem features.