Search results

Aims to develop a greyscale “painting system” by enabling the physical reproduction of digital texture maps on arbitrary 3D objects selectively exposing “pixels” of photographic emulsion with a robot mounted light source.

After reviewing existing methods of “decorating” 3D components, the properties of photographic emulsion are introduced and the nature of the rendering process' pixels discussed. A proposed path planning algorithm, used to derive both the robot's movement and the exposure times directly from a VRML representation, is then presented.

Results obtained from successfully rendering images on the surface of a test object are presented.

Limitations of current system include the overall process time and the inability to handle objects with concave geometry.

The system requires no bespoke production tooling and fills an automation gap in rapid prototyping and manufacturing technology that is currently occupied by hand painting.

This study aims to present a new haptic-enabled virtual assembly system for the automatic generation and objective assessment of assembly plans. The system is intended to be used as an assembly planning tool along the product development process.

The generation of product assembly plans is based on the analysis of the assembly movements and operations performed by the user during the virtual assembly execution, and the objective assessment of product assembly is based on the definition and computation of new proposed assembly metrics.

To evaluate the system, a case study corresponding to the assembly of a mechanical component is presented and analyzed. The results demonstrate that the proposed system is an effective tool to plan and evaluate different product assembly strategies in a more practical and objective approach than existing assembly planning methods.

Although the virtual assembly execution time is larger than the real assembly execution time, the assembly planning and evaluation results provided by the system are valid. However, the development of higher performance collision detection algorithms is needed to reduce the simulation time.

The proposed virtual assembly system is able to not only simulate and automatically generate assembly plans but also objectively assess them from the virtual assembly task execution. The introduction and use of several assembly performance metrics to objectively evaluate assembly strategies in virtual assembly also represents a novel contribution.

Rapid manufacturing processes provide designers, mechanical and process engineers with a lot of chances and opportunities. It is necessary to show them, how their work and their processes will change due to these new technologies.

Rapid manufacturing offers the chance to use the additive manufacturing processes to produce not just prototypes but advanced functional parts in small and medium quantities that can utilise a lot of design advantages that are provided by the process. We consult, as a German applied research institute, independent companies, helping them to introduce new product development and manufacturing processes, rethink the design of their products and to be aware of the advantages of upcoming manufacturing technologies.

Finds that a lot of products of today and especially of tomorrow could be produced by the new rapid manufacturing processes today and at competitive costs, if their design was adapted carefully using the new possibilities. New categories of products will come up too.

The acceptance of rapid manufacturing as a new production technology is still limited by the available manufacturing systems. The number of released materials is still small and the accuracy of the parts and the building speed is still not exactly rapid. The mindset of the decision makers and of the R&D departments has to be radically changed. There is a lot of development going on, so the situation will change…

Aspects of a visionary scenario for future productions and products are shown and some examples are demonstrated based on a customised robot gripper.

This work aimed at studying the use of capillary forces as a gripping principle in the handling of sub‐millimetric sized components. The goal was to present the results as design rules of so‐called capillary grippers.

Each parameter (surrounding environment, materials, volume of liquid, separation distance, gripper geometry and gripper size, relative orientation of the gripper with respect to the component) has been quantified, either numerically or experimentally. In some validation cases, both means have been used.

The capillary forces can be modified between a maximum F_max and a minimum F_min so that a component with any mass m between F_min/g and F_max/g can be picked up and released.

By comparison with some existing capillary grippers prototypes, this work is only a theoretical and experimental study. Nevertheless, its originality lies in the exhaustive study and quantification of all parameters so that most of the capillary grippers of the literature can be explained or improved with these results.

The main implication of the capillary gripping is that it provides an alternative to existing gripping principles (vacuum grippers, tweezers). This principle is strong enough (a few mN) and well adapted to pick up components with only one free accessible surface. The scaling laws are the most favorable (F∼L). It provides a “soft” picking, avoiding high contact forces.

The originality lies in the exhaustive quantification of the role of each parameter. These results can be used by researchers and designers.

This article presents a qualitative analysis of three focus groups convened during a study day for health and social care professionals, which reveals a strong perception of a philosophical difference in approaches to professional practice. The prospect of health and social care professionals working more closely together is welcomed, and evidence‐based practice should be encouraged and financially supported. While established educational strategies can be deployed to respond to the conventional perceived barriers to working together, more innovative models are needed. The authors commend the model of Significant Event Auditing.

Aims to investigate medical rapid prototyping (medical RP) technology applications and methods based on reverse engineering (RE) and medical imaging data.

Medical image processing and RE are applied to construct three‐dimensional models of anatomical structures, from which custom‐made (personalized) medical applications are developed.

The investigated methods were successfully used for design and manufacturing of biomodels, surgical aid tools, implants, medical devices and surgical training models. More than 40 medical RP applications were implemented in Europe and Asia since 1999.

Medical RP is a multi‐discipline area. It involves in many human resources and requires high skills and know‐how in both engineering and medicine. In addition, medical RP applications are expensive, especially for low‐income countries. These practically limit its benefits and applications in hospitals.

In order to transfer medical RP into hospitals successfully, a good link and close collaboration between medical and engineering sites should be established. Moreover, new medical applications should be developed in the way that does not change the traditional approaches that medical doctors (MD) were trained, but provides solutions to improve the diagnosis and treatment quality.

The presented state‐of‐the‐art medical RP is applied for diagnosis and treatment in the following medical areas: cranio‐maxillofacial and dental surgery, neurosurgery, orthopedics, orthosis and tissue engineering. The paper is useful for MD (radiologists and surgeons), biomedical and RP/CAD/CAM engineers.

This paper aims to investigate automatic assembly planning for robot and manual assembly.

The octree decomposition technique is applied to approximate a computer‐aided design model with an octree representation which is then used to generate robot and manual assembly plans. An assembly planning system able to generate assembly plans was developed to build these prototype models.

Octree decomposition is an effective assembly planning tool. Assembly plans can automatically be generated for robot and manual assembly using octree models.

One disadvantage of the octree decomposition technique is that it approximates a part model with cubes instead of using the actual model. This limits its use and applications when complex assemblies must be planned, but in the context of prototyping can allow a rough component to be formed which can later be finished by hand.

Assembly plans can be generated using octree decomposition, however, new algorithms must be developed to overcome its limitations.

This paper has proved that the octree decomposition technique is an effective assembly planning tool. As a result, an assembly planning system has been developed. Assembly plans for automatic and manual assembly can be generated automatically by the proposed system, which is a novelty since there are no fully automatic assembly planning systems for manual assembly reported in the literature.

Presents development and characterisation of a new metal/polymer composite material for use in fused deposition modelling (FDM) rapid prototyping process with the aim of application to direct rapid tooling. The work represents a major development in reducing the cost and time in rapid tooling.

The material consists of iron particles in a nylon type matrix. The detailed formulation and characterisation of the thermal properties of the various combinations of the new composites are investigated experimentally. Results are compared with other metal/polymer composites used in rapid tooling.

The feedstock filaments of this composite have been produced and used successfully in the unmodified FDM system for direct rapid tooling of injection moulding inserts. Thermal properties are found to be acceptable for rapid tooling applications for injection moulding.

Introduces an entirely new metal based composite material for direct rapid tooling application using FDM RP system with desired thermal properties and characteristics. This will reduce the cost and time of manufacturing tooling inserts and dies for injection moulding.

This paper illustrates an effective application of rapid prototyping (RP) to produce a high definition polymer model of a satellite structure prior to final machining of the aluminum panels. The benefits when using this type of model in the design and assembly stages of satellite fabrication make clear that RP can and should play an important role in the design and fabrication of small satellite structures.

Selective laser sintering was utilized to produce a full‐scale model of a novel modular small satellite structure. This model was then used as a tool for quality control, fit check, assembly process verification, mock‐up, and as a model for manufacturing tooling design.

This case study illustrates that the use of RP to create a model early in the design cycle is beneficial from a cost and time perspective even when applied to a product which will be produced in a quantity of one. In addition, the merits of RP mesh well with modular designs and for applications where assembly and test tooling is required to validate the quality of a product.

This paper illustrates an effective use of RP in the satellite fabrication industry. The benefits described are generally applicable to other complex systems which need design validation early in the design cycle.

There are few examples of the effective application of RP to produce models, but not the final product, of a complex structure in the satellite and other industries where small lot production occurs.

The aim of this study is to demonstrate the benefit of design flexibility afforded by the Arcam free‐form fabrication process in the direct manufacture of injection mould inserts with complex cooling channel configurations and the process efficiency and quality gains achieved through using such inserts.

The manufacturing process of a flood cooled injection mould insert using the Arcam EBM S12 layered manufacturing process is presented. The insert is then evaluated against two other inserts (one un‐cooled and one traditionally baffle cooled (BC)) in the manufacture of test components, with the temperature of the insert and components recorded. The process conditions were adjusted (reduced cooling time) to increase the core and component temperatures to identify the operational limits of the inserts. Thermal imaging was employed to visualize the thermal distribution within the BC and flood cooled (FC) inserts.

The cooling efficiency of the FC insert was found to be significantly higher than that of the other two inserts, and the homogeneity of the heat distribution of the FC insert was more even than the BC insert. It was possible to manufacture non‐deformed components using the FC insert with zero cooling time (ejection immediately after removal of holding pressure), this was not possible with the BC insert.

Provides a basis for the development of more efficient and thermally homogeneous inserts through the Arcam EBM process.

Provides a technology/process for the manufacture of highly efficient core inserts for injection moulding, offering the industry a competitive advantage through the potential for time and cost savings and higher quality components.

This is the first direct comparison of an Arcam EBM manufactured insert with complex cooling geometries against traditionally cooled inserts, particularly novel is the thermal imaging analysis of the cooling efficiency and distribution.