Ease Of Assembly Research Articles

Optomechanics for a four-stage hybrid-self-electro-optic-device-based free-space optical backplane

We present the design, fabrication, and testing of optomechanics for a free-space optical backplane mounted in a standard 6U VME backplane chassis. The optomechanics implement an optical interconnect consisting of lenslet-to-lenslet, as well as conventional lens-to-lens, links. Mechanical, optical, electrical, thermal, material, and fabrication constraints are studied. Design trade-offs that affect system scalability and ease of assembly are put forward and analyzed. Novel mounting techniques such as a thermal-loaded interference-fitted lens-mounting technique are presented and discussed. Diagnostic tools are developed to quantify the performance of the optomechanics, and experimental results are given and analyzed.

An optoelectronic sensor system for industrial multipoint and imaging spectrometry

The paper presents a compact integrated sensor system for industrial multipoint and imaging optical spectrometry applications. The sensor consists of a compact prism-grating-prism spectrograph combined with a matrix detector and signal preprocessing electronics. All the optical components are on a single optical axis, resulting in ease of assembly and adjustment, small size and low cost. The spectrograph can be used in the wavelength range 380–820 nm, with a resolution of 3 nm. In imaging spectrometry one axis of the matrix detector is used for the wavelength spectrum and the other for spatial location. The built-in microcontroller-based signal-preprocessing electronics compresses the CCD data before transfer. Test results for a 16-channel spectrometer demonstrate the suitability of the system for on-line multipoint colour measurement.

TPX TF magnet structure design

The design of the Tokamak Physics Experiment (TPX) utilized 16 superconducting toroidal field (TF) magnet coils supported by a wedged structure. The TF magnet structure supports and locates the poloidal field (PF) coils and must restrain the twisting and expansion forces generated by the interaction of currents and magnetic fields. This structure must also leave significant open space to permit access to the plasma chamber. The geometry and alignment of the magnet structural components must be controlled to meet very tight tolerances with respect to the operating toroidal magnetic field errors. During the preliminary design phase, the TPX TF magnet structure configuration was revised from a welded and bolted field assembly to one utilizing bolted joints only. These electrically insulated joints were specifically designed for ease of assembly and to provide the flexibility to adjust coil alignments at assembly to accommodate for manufacturing tolerance stackups. We report on the final preliminary design which meets all project design requirements.

Accounting for design

Design decides the cost of a product. Ease of manufacture, ease of assembly and a product that customers want bestow competitive advantage on a firm. State-of-the-art accounting systems will reflect resource usage. State-of-the-ark systems will not. Financial benefits can be immense-but many will take time to accrue. Design for service confers benefits on the customer-benefits that may be reflected in the price. Design for disassembly leads to benefits in recycling. Both products and individual parts can be designed for manufacture. Part DFM provides component features in a cost effective way both in choice of materials and in the manufacturing process. Product DFM designs for assembly using the minimum number of parts compatible with product features and overall cost. The author argues that effective accounting techniques are a prerequisite for any real process improvement.

Active Vibration Control of Rotating Machinery With a Hybrid Piezohydraulic Actuator System

An integrated, compact piezohydraulic actuator system for active vibration control was designed and developed with a primary application for gas turbine aircraft engines. Copper tube was chosen as the transmission line material for ease of assembly. Liquid plastic, which meets incompressibility and low-viscosity requirements, was adjusted to provide optimal actuator performance. Variants of the liquid plastic have been prepared with desired properties between −40°F and 400°F. The effectiveness of this hybrid actuator for active vibration control (AVC) was demonstrated for suppressing critical speed vibration through two critical speeds for various levels of intentionally placed imbalance. A high-accuracy closed-loop simulation, which combines both finite element and state space methods, was applied for the closed-loop unbalance response simulation with/without AVC. Good correlation between the simulation and test results was achieved.

Bond and Behavior of Composite Reinforcing Bars in Concrete

Abstract Wood, concrete, steel, and combinations thereof have traditionally been used in civil infrastructure. However, each of these materials has its own drawbacks that range from susceptibility to environmental attack to the large deadweight of the material itself. Steel reinforcing bars, commonly known as rebar, although extensively used for reinforcement of concrete, are susceptible to corrosion and the rapid deterioration of the structure. A number of other factors including chemical and corrosion resistance, better fatigue performance and increased durability in adverse environments, lower overall life-cycle costs, lighter construction material, potential ease of assembly and installation, reduced costs of transporting modules to site, use of modular construction, design flexibility, and overall lower energy consumption have motivated the investigation of the use of composites in civil infrastructure. The present paper focuses on the results of the use of composites as reinforcements in concrete be...

Low-cost molded packaging for optical data links

In order to lower the cost of optical data link packaging, a new technology has been developed which integrates optical and electrical components in a single, sealed, transfer molded package. This technology utilizes leadframes for low cost and mass handling. Overmolding is used for package sealing and optical port alignment. A unique process, two-step transfer molding, allows for internal shielding, intermediate IC testing, ease of assembly, and IC package sealing. An injection-molded outer housing is used for connector insertion and external shielding (through the use of conductive plastics). The first application of this technology is a high performance optical transceiver package for the growing FDDI market (125 Mb/s). With a duplex MIC connector, this package conforms to an industry standard outline and pinout. The optical transceiver easily meets full FDDI specifications. The design integrates an LED, PIN, transmitter IC, receiver IC, and two capacitors in a single, overmolded package. The final assembly sequence was conceived using the latest Design For Simplicity (DFS) principles. This paper describes the design concept and prototype model performance results. >

Where No Flag Has Gone Before: Political and Technical Aspects of Placing a Flag on the Moon

The flag on the Moon represents an important event in vexillological history. This paper examines the political and technical aspects of placing a flag on the Moon, focusing on the first Moon landing. During their historic extravehicular activity, the Apollo 11 crew planted the flag of the United States on the lunar surface. This flag-raising was strictly a symbolic activity, as the United Nations Treaty on Outer Space precluded any territorial claim. Nevertheless, there were domestic and international debates over the appropriateness of the event. Congress amended the agency’s appropriations bill to prevent the National Aeronautics and Space Administration (NASA) from placing flags of other nations, or those of international associations, on the Moon during missions funded solely by the United States. Like any activity in space exploration, the Apollo flag-raising also provided NASA engineers with an interesting technical challenge. They designed a flagpole with a horizontal bar allowing the flag to “fly” without the benefit of wind to overcome the effects of the Moon’s lack of an atmosphere. Other factors considered in the design were weight, heat resistance, and ease of assembly by astronauts whose space suits restricted their range of movement and ability to grasp items. As NASA plans a return to the Moon and an expedition to Mars, we will likely see flags continue to go “where no flag has gone before.”

Optimizing Biological Activity of Lipophilic Compounds in Cultured Cells by Improving Delivery: Theoretical and Practical Considerations

The use of lipophilic compounds in the study of signal transduction and other cellular processes is often complicated by the need to deliver compounds that are minimally soluble in water to cells in culture. A typical approach is to dissolve the lipophilic compound at high concentration in organic solvent and then to dilute the solvent in aqueous medium. However, such an approach usually results in precipitation of the compound in the aqueous medium and may minimize delivery of the compound to cells. Three techniques to keep the lipophilic compound In a nonprecipitated and stable form that will be readily available to the cells are described. They involve the use of protein carriers, liposomes, and emulsions. Particular attention is given to the use of emulsions, since this technique combines the advantages of a high capacity for lipophilic compounds, ease of assembly, and minimum contact between the lipophilic compound and water. Although the techniques differ with respect to the mechanics of combining the compound and the carrier, they all consist of a two-phase system dependent on partitioning between the carrier and the cells. Due to the need to take partitioning into account, all of these techniques differ from homogeneous solution-phase delivery. Therefore, in addition to descriptions of the techniques, criteria for both experimental design and analysis of data generated using two-phase systems are presented. In combination, the use of methods appropriate for delivery of lipophilic compounds to cells and the application of relevant calculations and analytical procedures provide the means necessary for design and Interpretation of experiments using lipophilic compounds.

Prefabricated wall systems and the North American home‐building industry

Cost, craftsmanship, technical performance, durability, flexibility and ease of assembly were analysed for nine types of wall systems. Although the products were found to be technically superior to conventional construction techniques, the accompanying disruption to the standard opertional routines were considered to be obstacles to achieving widespread acceptance.

Effect of plating and temperature on the strength of shrink fitted assemblies

Interference fitted assemblies are most widely used in engineering practice because of excellent load carrying capacity, reliability and ease of assembly. For a specific fitting with fixed interference, the strength can be improved by thermal treatment and also by introducing a layer between the mating parts through plating the shafts. An experimental investigation of the above factors on the fitting strength is obtained and discussed in detail.

Cost modelling for electrical interconnect design justification

Abstract It is vital, in this competitive global market, that a product be well designed with ease of assembly as well as low product cost and yet meet its functionality objectives. It is therefore essential that a tool be developed to estimate the manufacturing cost of the product during its conceptual design phase. In this paper, the development of cost models for electrical interconnect design is discussed. The cost models can be used by designers in estimating the manufacturing cost of their designs and selecting the design that is economical to produce and functionally, meets the required specifications.

ASSEMBLY/DISASSEMBLY SEQUENCE PLANNING

The ever‐increasing demand for rationalization of manufacturing activities requires closer co‐operation and integration between design and production planning. Since the impact on the overall cost of production of designing a product for ease of assembly was realized, feedback from assembly planning to the design process has become important for improving the design. Traditionally, planning for assembly takes place after the design of the product has been completed. Often it proves necessary to modify a design, because some aspect is not particularly convenient or efficient under the available assembly facilities. However, considerable time and cost savings can be made by making assembly‐planning information available to design engineers, so that they can take account of assembly factors when designing a product.

Simultaneous electroelution of proteins from denaturing or native gels into a well matrix

An electroelution device that is based on a semidry blotter and that allows the simultaneous elution of proteins or other charged macromolecules from one-dimensional gels is described. It consists of a central plate that has a matrix of oblong wells arranged in eight columns of 32 wells each, such that when a gel is placed on the plate each lane of bands is underlaid by a column of wells. The plate is placed between the electrodes of a semidry blotter and the wells are sealed by a dialysis membrane resting on polyacrylamide gel block, prior to being filled with transfer buffer. Using radiolabeled molecular weight standards resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, elution is shown to require 30–60 min for 90% or better of proteins between 10 and 120 kDa to be removed from the gel. The recovery volume is 200 μl per well and losses due to adsorption onto the dialysis membrane are minimal. β-Galactosidase eluted from a nonreducing, non-denaturing gel was shown to be quantitatively active. The advantages of the device include its ease of assembly and operation, its speed, its reproducibility, and the fact that no gel slicing is required since all proteins are eluted simultaneously, allowing large-scale screening of multiple protein fractions.

An Introduction to the Design and Behavior of Bolted Joints

Abstract Although the title of this book includes the word “introduction”, the treatment of the subject is extensive and complete. The material goes well beyond the coverage of bolted joint design received in a typical undergraduate machine design course. The easy-to-read text begins with the fundamentals of bolt strength, deformation, and material selection and proceeds to cover the topics of preload, torque, and stretch control. The emphasis is on practical considerations for the efficient design of joints, including cost, ease of assembly, inspection, and disassembly. This second, revised edition has expanded the coverage of corrosion, fatigue, gaskets, and ultrasonic measurement of bolt strain. Also included are discussions of the failure modes and mechanisms of bolted joints. Case histories from industry are presented throughout the text to illustrate key points. Many up-to-date references are presented at the end of each chapter to allow the reader to pursue individual topics further, if desired. The text contains several appendices with useful tables and formulas for quick reference. The author has broad experience in the subject area from many years as a consultant to the power generation and nuclear industry, active participation on society working groups such as ASME and PVRC, as well as the presentation of numerous seminars on the topic. This book would serve as a valuable desk reference for engineers concerned with the design and performance of bolted joints.

A laser photometer that is assembled in seconds

A versatile photometer that can be assembled in seconds, it's ease of assembly is unrivaled.

A new approach to a high efficiency inductive store

A topology has been developed for a highly efficient inductive store suitable for pulsed-power applications. The design features high L/R ratios without having to cryogenically cool the conductors. This allows for high efficiency charging of the inductor from low-impedance DC sources such as batteries or homopolar generators. The inductor design produces very low external flux, which makes it suitable for laboratory applications where magnetic pressures on adjacent conductive structures and EM (electromagnetic) interference noise introduced into control and instrumentation systems is a concern. The inductor may be fabricated in modules for cost-effectiveness and ease of assembly. >

Estimating cycle time in design for robotic assembly

Abstract The Design for Robotic Assembly1 handbook offers a method for quantitatively evaluating a product's ease of assembly by robots. Additionally, it helps the designer estimate the cost of assembly associated with each part, pointing out aspects of part design that incur additional cost. This paper describes robot assembly task time data derived from laboratory tests and industrial experience. It also shows how these data can be substituted for the original values on the handbook data sheets for estimating part assembly times at a two-arm robotic assembly station. Using these new time values, the handbook method yields cycle time estimates that are within 5% of those drawn from computer simulation, while the original data sheet values give estimates that are approximately 20% lower than the computer simulated times. The principal difference is in the amount of time attributed to robot gripper changes.

Aerospace Materials Research Opportunities

As we approach the second century of aerospace, increased emphasis is being placed on endurance, reliability, ease of manufacture, and lower cost, in addition to weight saving. This change in emphasis will have a major effect on not only the selection of materials, but on how materials are integrated into the total system design process. Subsonic aircraft will continue to play a major role in our future with emphasis on increased durability and lower cost. Non-metals that do not corrode are attractive; however, the issues of reliable fracture resistance to ensure safety and durability as well as ease of manufacture and inspection will be key. Higher performance engines and hypersonic aircraft will require higher temperature materials (including a substantial amount of non-metals) along with reliable toughness and ease of manufacture. In space, weight will continue to be a major driving force along with the need for long term vacuum and radiation stability. Ease of assembly and multifunctional use (e.g. electrically or thermally conducting structure) will be additional needs for spacecraft materials. We have reached a point in the evolution of structural materials where we are moving away from processing naturally occurring materials toward synthesizing designed microstructures to perform specific functions. The mathematical modeling of microstructure–property relationships and new chemical and biotechnical synthesis techniques appear to be critical technologies for the future. In addition, the future materials developer will need a broader understanding of the total structural life cycle so that the impact of utilization, maintenance, and training requirements in the design of new materials can be considered.

Aerospace materials research opportunities

AbstractAs we approach the second century of aerospace, increased emphasis is being placed on endurance, reliability, ease of manufacture, and lower cost, in addition to weight saving. This change in emphasis will have a major effect on not only the selection of materials, but on how materials are integrated into the total system design process. Subsonic aircraft will continue to play a major role in our future with emphasis on increased durability and lower cost. Non‐metals that do not corrode are attractive; however, the issues of reliable fracture resistance to ensure safety and durability as well as ease of manufacture and inspection will be key. Higher performance engines and hypersonic aircraft will require higher temperature materials (including a substantial amount of non‐metals) along with reliable toughness and ease of manufacture. In space, weight will continue to be a major driving force along with the need for long term vacuum and radiation stability. Ease of assembly and multifunctional use (e.g. electrically or thermally conducting structure) will be additional needs for spacecraft materials. We have reached a point in the evolution of structural materials where we are moving away from processing naturally occurring materials toward synthesizing designed microstructures to perform specific functions. The mathematical modeling of microstructure–property relationships and new chemical and biotechnical synthesis techniques appear to be critical technologies for the future. In addition, the future materials developer will need a broader understanding of the total structural life cycle so that the impact of utilization, maintenance, and training requirements in the design of new materials can be considered.