Europe’s Flagship R&D Project for Rapid Manufacturing: Custom-Fit

After over two years of preparations, project proposal writing, negotiations with the European Commission and discussions with the various interested bodies and partners, the Kick-Off Meeting for the FP6 Integrated Project Custom-Fit took place on September 21 and 22, 2004 at Delcam’s headquarters in Birmingham, United Kingdom. More than 30 European organizations ‘sailed off,’ with the objective to “create a fully integrated knowledge-based system for the design, production and supply of personalized custom products or components using rapid manufacturing techniques” (see Project Partners sidebar, page 26).

Delcam accepted the challenge to not only coordinate and manage this extremely ambitious multi-client, multi-national and multi-disciplinary European-wide research and development project, but also to be one of the leading partners with the role to develop advanced technologies to design customized parts based upon personalized ‘imprints’ of the customer.

This article provides a general overview of the current project results (after three years of work) with a detailed overview of the project results in which Delcam was directly involved as project partner. The overall project progress can be studied by visiting the project Web site at www.Custom-Fit.org, while regular updates can be received by subscribing to the project’s mailing list.

The Custom-Fit Project

Custom-Fit is being undertaken as an Integrated Project within the 6th Framework Programme of the European Commission (also visit http://ec.europa.eu/research/fp6). Within these integrated projects, industry representatives, innovative SMEs and research organizations are cooperating closely to enable a step-change in a certain field of technology. The Commission prefers that these projects are led by the industry representatives to ensure that project results are really implemented in their industry to the general benefit of society at large. Custom- Fit is an industry-led integrated project coordinated by Delcam and was initiated by the Rapid Manufacturing Research Group at Loughborough University (UK) and TNO Science and Industry (Netherlands). The project, which is scheduled to last for four and a half years (from 2004), is regarded by the Commission as central to European research concerning rapid manufacturing. With a total budget of 16 Million Euros ($23.5 Million U.S.) including a funding of more than 9 Million Euros ($13.2 Million U.S.) from the European Commission, both the project members and the Commission express their belief that project outcomes will benefit both society and industry in Europe.

The members are made up from a broad base of organizations across Europe, in the fields of manufacturing, design, scanning, materials and consultancy. This unique mix of disciplines offers the potential to change the paradigm of manufacturing, service and distribution, with technologies to produce very complex and highly-customized products at the place and at the time that they are needed.

The Innovations of the Project

In order to create a ‘fully-integrated system for the design, production and supply of personalized custom products or components using rapid manufacturing techniques,’ several breakthrough developments and/or innovations have to be achieved:

1. New business structures to accommodate and exploit the new rapid manufacturing process chains1
2. The ability to transform all kinds of captured geometrical (human) data into a standard neutral format enabling bespoke product design2
3. Design modeling software that is suitable for designing functionally-differentiated products (including graded structures and materials) and able to integrate nongeometric requirements3
4. A manufacturing process suitable for the rapid production of complex, bespoke products, including the development of novel material combinations (including graded structures and materials) for the rapid manufacture of the products4

The various innovations have to be demonstrated in ‘real life’ situations. For this part of the project, several case studies have been defined in which the full sequence from geometry capture, product design and manufacturing, and consumer use is being evaluated.5 In four of these case studies the design modeling software developed by Delcam has been used. Information on the other case studies can be found at www.Custom-Fit.org.

During the course of the project, outcomes that are not protected by IPR are being disseminated to the general public. Partner AIJU (Spain) is responsible for this activity. Through the project Web site, mailing list and many press releases, the general public in Europe and abroad is regularly updated of the results achieved to date and the general progress of the project.

The project results will be used to create training modules for engineers, managers, scientists and educators.6 This will allow the developments from the project to be made available to those organizations in Europe that were not involved in the project but which can contribute to the future of high added- value manufacturing in the European Union. Four applications of this project are described in more detail in the following case studies.

Improving Helmet Comfort with Customization

Helmets are designed to absorb and disperse impact during an accident. The U.S. National Highway Traffic Safety Administration states that helmets are 70 percent effective in preventing brain injuries and that motorcycle riders not wearing helmets are three times more likely to suffer brain injuries (NHTSA, Traffic Safety Facts 2004). Studies performed within Custom-Fit have shown that 15 to 20 percent of all full-face composite helmets are ill fitting and that 5 percent of motorcyclists cannot find helmets that fit their head geometry.

Mass production cannot solve this issue; only partial personalization can be achieved by adjusting the thickness of the helmet’s padding. A new manufacturing philosophy is needed to produce a fully-customized helmet, perfectly shaped for the geometrical and nongeometrical features of individual riders. When trying to satisfy user comfort, it is not only necessary to consider the geometrical requirements and a good product fit, but it is also important to consider non-geometrical requirements that define the interaction in the zones of contact such as the pressure distribution between the product and the rider’s head and the level of comfort felt by the rider. This can be achieved by customizing the inner liner (see Figure 4) rather than the whole helmet, thus saving time and money for the consumer and getting around legal issues of safety standards.

The process from the beginning to the end is comprised of five steps:

1. Capturing geometrical data
2. Capturing non-geometrical data
3. Designing the Custom-Fit inner liner
4. Developing the manufacturing process for the inner liner
5. Manufacturing the inner liner

During these steps, a single project data file (NSF) was used to store the geometric and non-geometric results of the various activities:

1. Capturing geometrical data—A 3D body scanner at project partner Human Solutions (Germany) was used to scan the rider. The scanned data of the head was trimmed, repaired and aligned as required to enable its use downstream. During the project, Human Solutions developed ScanWorx CFX software to extract the full geometry in general and five specific dimensional variables
2. Capturing non-geometrical data—To obtain the non-geometrical information about the pressure between the helmet and the user’s head, a customized recording system of static pressures developed by project partner IBV (Spain) was used to generate a pressure map. To determine typical users’ views on comfort, six important zones on the head were located that correlated with the pressure map data and a questionnaire developed based on five levels of comfort.
3. Designing the Custom-Fit inner liner— The design of the inner liner depends on the geometric customer data (scan of head), the non-geometric data and the existing helmet geometry into which the liner has to be integrated. Delcam developed a design system for this operation based upon its PowerSHAPE advanced 3D free-form modeling system. The system executes the required sequence of operations completely automatically. By importing the full CAD model of an existing helmet from the project partner Mavet (Italy) and the scan of the consumer’s, the Custom-Fit inner liner is generated automatically using advanced morphing technologies that take into account a rider’s non-geometric demands. Without the constraints of traditional molding techniques where undercuts and internal cavities are difficult and complex to produce, Delcam was able to use the freedom offered by rapid manufacturing to introduce cooling channels into the liner. To enable time-effective and cost-effective manufacturing the resulting inner liner is split into five sections.

Current rapid manufacturing technologies cannot yet manufacture low-density polyurethane foam, which is the normal material for the inner liner. To overcome this problem, the material and its properties had to be mimicked by using laser sintering and future PPP manufacturing technologies developed by project partner De Montfort University (UK), in combination with different, lattice-like internal structures (see Figure 10). This is possible due to the unique capability of rapid manufacturing technologies to make virtually any shape that might be needed. More than 30 different structures have been designed using Delcam’s advanced design system, in combination with software from project partner Marcam (Germany) to process repetitive Boolean operations.

STL files generated by the Delcam software are used in the rapid manufacturing machines. The inner liner is produced using a straightforward honeycomb structure, which is a good compromise in mimicking the polyurethane foam and being cost effective in design and manufacturing. Figures 13 and 14 show an inner liner before and after integration in a ‘standard’ helmet of partner Mavet.

Five customized helmets were produced for five professional test riders. The initial feedback from these riders was that the customized helmets ‘feel good ’ and fit comfortably to their shape. The manufacturer, Mavet, also assessed the results positively. The next step was to run longride tests with the new helmets, to confirm the improvement in comfort per-ceived by the riders. Objective measurements also were under- taken by using pressure sensors to measure the actual pressure exerted by the helmet on the head. This was done for one rider and the pressure distribution was found to be significantly improved.

Obviously, safety remains the main issue with any helmet and is improved as the riders experience more comfortable fitting with the evenly spread weight of their helmets; however, the mechanical characteristics must not be reduced. Currently, this is guaranteed by using the same amount of expanded polystyrene in the new helmets as is used in standard, certified examples. This material is mainly responsible for shock absorption in case of an accident. The thickness of the custom fitting inner liner must stay within a defined range to allow similar amounts of EPS to be used. As part of its contribution to the project, partner BPO (Netherlands) is currently examining the appropriate value for the widths of the different materials, using a special virtual-testing methodology. For this, the ‘digital Custom-Fit helmet’ is crash tested virtually in a drop-and-pull-off test.

Many more possibilities exist for the geometric structures within the Custom-Fit inner liner. Currently, channels following the surface are being added using Delcam’s design platform, partly to make the structure mimic the polyurethane better but mainly to provide air-flow channels to really refresh riders’ heads during long rides. Moreover, special customization of the mechanical characteristics of the Custom-Fit inner liner is being incorporated to increase safety levels. All of these geometrically-demanding operations will be integrated into Delcam’s design platform as part of the company’s contribution to this part of the project.

The viability of customized helmets has been demonstrated. The use of Delcam’s advanced design platform has been shown to provide a comfortable and safe helmet. This case study has enabled Delcam to not only provide a customized helmet design system, but also to improve its technologies, in particular for morphing and repetitive Boolean operations. In the bigger picture, it has not yet been possible to implement the complete rapid manufacturing cycle for customized helmets as certification has not been undertaken. This has hampered the implementation of the distribution of the helmets into shops and the use of the knowledge-based system developed by Delcam based upon its PS-Team platform. The system has been tested in an internal trial and the project partner involved judged it to be easy to use. With the continuing work on certification and on the supply of the customized helmet in reasonable time and within reasonable production costs, there are currently no major barriers foreseen that prevent this from being a successful outcome of the Custom-Fit project.

Improving Comfort with Customized Seats

Motorcycling is an increasingly popular method of transport. Nearly 15 million motorcycles were in use in Europe during 2004. This reflects the current trend in society of individualization and freedom. A three- month survey was carried out by Loughborough University and Ducati (Italy) as part of their work within Custom-Fit and produced 3,200 responses. The main results were:

• 81 percent said yes to a customized seat and were happy to pay extra
• 51 percent had experience of seat discomfort during short distance rides
• 92 percent had experience of seat discomfort during long distance rides

Therefore, improving seat comfort through customization based on individual body geometry is a valid application that can find its place in the market with benefits for many European citizens.

Just like with the helmet, mass production cannot solve this issue; only partial personalization can be done based upon a pressure map by varying the different cushions inside the seat between the rigid plastic bottom and the soft cover. The pressure map could be represented as a discomfort map. This could be translated into different pieces of cushioning, representing a softer or harder structure in the places where the rider wanted them. These results were judged positively by the riders but more benefits could be obtained by changing the shape of the seat and the internal structure by using the possibilities available from rapid manufacturing technologies.

The process from the beginning to the end is comprised of five steps, with the first three steps similar to the helmet process:

1. A pressure map is derived by using a pressure-blanket on the standard seat while the rider is seated on the motorbike. Simultaneously, the rider is questioned about the relationship between his position on the bike and his level of comfort. This results in the comfort map by using an IBV application developed in Matlab as part of its responsibilities in the project.
2. Digitally, the comfort map is laid onto a CAD model of the seat to define regions in which the internal stiffness of the seat’s structure will be altered.
3. The upper side of the external shape of the seat is automatically morphed to fit measurements of the rider’s size and shape.
4. Automatically build the CAD model of seat’s internal spring-structure for each comfort region for maximum comfort.
5. Manufacture of the Custom-Fit cushion.

During all these steps, a single project data file was used to store the geometric and nongeometric results of the various activities:

1. Transform the comfort map to zones in the CAD file of the seat—From the pressure map, partner IBV analyzes the results and produces a “comfort map.” A Matlab application developed by IBV translates the comfort map values into data points that can be combined with the 3D CAD file of the seat. Delcam’s advanced 3D free form modeling package PowerSHAPE is used for the modeling. This results in representation of the seat with several zones of equal comfort or discomfort.
2. Customized fore or aft sections of the seat—Based upon the same comfort map, advanced morphing algorithms are deployed to increase the thickness of the material in the fore and aft sections of the seat. As a result, the driver’s body is better matched to the seat, resulting in an improved feeling of comfort.
3. Based upon algorithms developed in the project, different barrel geometries are integrated into the seat design. Hard barrels are integrated where the rider needs more stiffness and soft barrels where the rider needs less stiffness to provide the best feeling of comfort based upon the comfort map provided by partner IBV. Figure 26 shows the digital representation of the standard seat and the Custom-Fit seat designed using developments in the project by IBV and Delcam.
4. The first full-scale custom fit seats are currently being manufactured using selective laser sintering (SLS) technology. In the near future, De Montfort’s PPP manufacturing process will be implemented which promises to deliver parts at a dramatically more cost-effective level and at the same time, enable the use of a range of advanced materials with superior cushioning properties.

The customization process from the comfort map looks promising. This approach has not been used before. The integration of the springs is an innovative approach which enables a customized product to be created without dramatically changing its shape. On motorbikes, this aesthetic advantage is seen as a step-change in customization of seats. However, several improvements are needed, including design improvements for the springs to increase their fatigue properties and more investigation of the correlation between comfort and compression resulting in a more advanced distribution of weight using finer variations in the internal structure’s shape. Most importantly, testing of the current result by riders needs to be executed followed by a process and product cost re-evaluation to see whether the cost for the improved comfort is within the limits that the riders set in the Internet survey.

Customized Toy Vehicle Seats

To demonstrate the social benefits and implications that rapid manufacturing technologies can have, project partners AIJU, along with the FAMOSA Group (Spain) and Delcam, initiated a case study dedicated to seat customization for battery-powered toy vehicles (like cars and quads) for disabled children.

The benefit of personalization by adapting a child seat for vehicles must be considered from two important aspects. The first one refers to the rider’s security. Consider a child affected by a lower body physical incapacity that prevents them from sitting in the same way a child without the disability would. In a customized seat, the child would be more tightly held and supported within the vehicle and consequently would benefit from increased security. The second aspect, directly derived from increased safety/security, is the greater feelings of comfort that will make the child want to play longer.

The customization to make an adaptation to the child’s body shape begins with geometric data captured through a deformable cushion that changes to the child’s shape yet keeps its shape when pressure is removed from it. As a test case, a seven-year-old child volunteered to help. He suffers from abnormal movements in his left hip joint to such an extent that the leg can rotate through almost 360°. This hinders his mobility and limits his use of any type of vehicle seat. The aim, with a customized seat manufactured using Custom-Fit technology, was that the child would fit perfectly into the seat and be completely supported, reducing the possibility of falling. After sitting on the cushion the child’s body shape and support points are firmly embedded onto it ( see Figure 29). By using a 3D laser scanner, a point cloud is generated from the cushion and transformed to a surface representation (see Figure 30, page 34). Through automation of Delcam’s advanced 3D modeling system PowerSHAPE (using the improved algorithms as a result of the Custom-Fit project), a merge was made between this surface representation and the CAD file of the toy’s seat. This produced a single combined digital file (cushion plus seat) representing a completely individualized seat, tailored to the special characteristics of the child (see Figure 31, page 34). For the first prototype, selective laser sintering is being used, but such seats were manufactured using the PPP manufacturing process of DeMontfort University later in the project. After manufacturing, the customized seat was assembled to the toy car and ‘customer satisfaction’ was monitored along with the predicted safety improvement.

Improving Patients’ Quality of Life with Customized Implants

With lengthening life expectancy in Europe, there will be an increasing need for knee replacements and the market is expected to have a compound annual growth rate of 5.7 percent7. This challenges the medical industry to provide patients with high-quality products to improve their quality of life. Custom-Fit is aiming to manufacture customized implants with graded materials in which “bone-friendly” materials are combined with wear-resistant materials to provide long term stability where the molecular structure of graded materials transmit the forces more effectively than current steel plates.

The Custom-Fit process allows doctors to customize implants that fit the individual anatomy of the patient, improving the stability of the implant. Due to IPR issues, the process steps can’t be discussed in detail, but in general the process is as follows:

• Patient data is obtained via MRI and CT scans.
• The scan is translated to a surface model represented by triangle (STL format) of the bone’s anatomy.
• The geometric design representing the customer-specific design parameters for a customized implant is automatically provided with minimal interaction from the surgeon. This is produced using advanced algorithms developed by Delcam in the project and integrated in the company’s PowerSHAPE design platform.
• Based upon the shape of the plate produced by Delcam and optimization software developed by partner IFAM (Germany), an optimized implant is generated including a graded material distribution.
• Tests are currently being performed with Custom-Fit partner Sintef’s (Norway) MPP process to manufacture this functionally graded knee implant.

The project partners involved are constantly improving their methodologies to advance the project outcomes. Further work is also expected to improve the link with the fixture and planning of the operation by the surgeon.

Three Years at Sea with the Flagship

The objectives set at the start of the project were (and are) rated by the European Commission Reviewers as ‘extremely challenging.’ All the partners faced many challenges not only on the technical side, but also on the management side of this multiclient, multi-national and multi-disciplinary European-wide research and development project. In turn, the project has developed technologies that are being used in the case studies to demonstrate the full possibilities of the rapid manufacturing process cycle. At the beginning of the project it was only a vision on paper, but now customized seats, helmets, knee and jaw implants and prosthesis become reality and are tangible during project meetings. This is giving an energy boost to the project partners both on the research side and on the end-user side. Both the researchers and the end-users want to make sure that the best results are being obtained that will benefit themselves individually as well as the project.

Chris Lewis Jones is the project coordinator for Custom-Fit. He has been coordinating this project since 2004. Chris studied Mechanical Engineering on BSc level at Herriot Watt in Edinburgh (UK). Upon leaving the University in 1985, he joined Delta Cam Systems, which became Delcam PLC in 1989. During this time, Chris worked in the development department of CAD/CAM. In building up the team to develop Delcam’s CAD product, PowerSHAPE, he has managed a team of more than 25 developers. He became Product Manager of PowerSHAPE in 2000 with the responsibility for development and global marketing of the product to the company’s network of re- sellers. This involves writing marketing materials and giving presentations for customers, perspective customers and international conferences.

Jan Willem Gunnink is the consortium manager for Custom-Fit. Since Delcam saw the benefits of joining and actively participating in Research and Development projects on a European level, Jan Willem joined the company in 2006 as Delcam’s manager of European Research & Development Projects. He is responsible for the day-to-d ay management of the Custom-Fit project and several other international research and development projects Delcam is involved in. Jan Willem studied Mechanical & Production Engineering on MSc level at University of Technology Eindhoven (NL). Upon leaving the University in 1994, he joined TNO, the Netherlands Organization for Applied Scientific Research. After being engineer, project manager and group leader, he became department manager of more than 20 full time researchers in the area of Manufacturing Technology. Jan Willem has considerable experience in managing R&D projects and has published more than 50 papers in the area of innovative design and manufacturing.

Acknowledgements: The authors would like to thank the European Commission for their support to the Custom-Fit project. In particular the Project Officer Christophe Lesniak and Project Reviewer Prof. Ulrich Berger for their critical but therefore constructive view on the Custom-Fit project, the Scientific and Industrial Advisory Boards for their work and critical reviews, the Custom- Fit partners for their efforts to achieve our goals and to cooperate in such a positive atmosphere, our colleagues at Delcam for their hard work and the Board of Directors of Delcam PLC for their belief in continuous innovation.