Powering ahead to tomorrow’s designing
Tom Shelley journeys to the home of the Alamo to receive a vision of the future of engineering design.
The whole direction of engineering design is in the process of changing as the ideas of online design communities and electronic networking take hold in the US, with other parts of the world likely to follow. Examples seen at this year's SolidWorks World Event in San Antonio, Texas, include a car designed through an online community and produced in a local micro factory in such a way as to offer the opportunity of profit to the designer and the manufacturers, whilst benefitting from design input from both potential customers and professional engineers.
Also inspirational was a 'bionic stuntman', for whom a small engineering firm has developed the capabilities to outperform regular humans, and is opening up new avenues in engineering philosophy. At the same time, two of the pioneers of the race to the Moon offered reminders of both what can go wrong, and how things can be put right, and the huge advances that were made in crisis management, simulation, microchips, materials and computing technologies as a result, and the potential to take these on another leap to cope with challenges yet to come.
The first online, community-produced car – the 'Rally Fighter' produced by Local Motors, had so many people round it at SolidWorks World that it was difficult to get at it to take photographs. A true American muscle car, its development process was revealed by Mike Pisani, the company's senior vehicle engineer. The idea started as a 2D sketch by a student, Sangho Kim, a graduate of the Art Center College of Design in Pasadena, California, who posted a 2D sketch to the Local Motors online community in 2008 for review and critique.
Community feedback was immediately positive and many demanded that the car be built. Together with the community and the company's design team, Sangho Kim designed the first production vehicle, earned $20,000 in prize money and launched his career. The active, registered community is currently 9,500 strong, and might have been expected to come up with something eco as its prime project, but this is still the USA and the Rally Fighter has a 6.2 litre BMW V8 engine, which produces 430HP.
Pisani says the car went from sketch to working prototype in 15 months and to production in the company's first micro factory in Phoenix, Arizona in 18 months. Body tooling design was undertaken with the aid of Catia, Rapidform was used to scan in surfaces, rapid prototypes were produced with Z Corporation printers, Class A surfaces were produced with Autodesk Alias and Catia, and the rest of the body with SolidWorks.
All CAD data may be downloaded from the website and the factory is assembling production cars. Purchasers are expected to spend two three-day weekends doing this themselves, with assistance, of course, to help them get to know their cars more intimately. At the time of writing, there have been $1,000 deposits placed on cars up to build number 136. All CAD data is downloadable from the website.
Pisani said that by the time anyone has had a chance to copy their current design, they will have moved onto others. The next competition announced on the website is to build a new military vehicle with DARPA. The UK's Centre for Defence Enterprise already interacts with those seeking to develop new projects online as opposed to on paper and Dassault Systèmes is convinced that the future of design lies with secure online communities.
The 'bionic stuntman' is named Casey Pieretti, who is a below-the-knee amputee. Working with him is Bill Spracher who owns a small five to six man company primarily making parts made of polyurethane. They have gained fame through a pilot TV programme 'Bionic Builders', broadcast on the Discovery Channel. Their first development was a leg fin, now a commercial product, because Pieretti likes free diving, but this led onto a motorised propeller leg and a rock climbing foot, which has also become a commercial product, sold with rock climbing shoes from a leading supplier.
Pieretti said that most of his stunt work consisted of falls and other conventional stunts, but, added that, "Everybody comes into the stunt world with a special talent", and his is being able to lose his leg, which he did in Starship Troopers, when it gets bitten off by a large bug, or replace his normal prosthetic leg with an air ram, which allows him to make spectacular jumps. However, both men said that their goal was to make amputees and also healthy humans in general not just "enabled" but "super enabled".
Pieretti added that: "One of my projects is to develop a wheelchair that will enable paraplegics to get out into the mountains." Technical challenges are what NASA thrives on, ever since President John F Kennedy announced the goal of sending men to the Moon. Captain Jim Lovell, commander of Apollo 13 and Gene Kranz, who was mission controller, gave a spell binding inside account of what went wrong and how they dealt with it.
Kranz said that "High tech accidents don't come about from a single event" and explained how the problems which led to the explosion of the oxygen tank that blew the side off the Apollo 13 spacecraft arose from. "Five distinct events", which he detailed. They said that NASA does large numbers of simulations with scenarios of different things happening which Lovell said produced, "Thousands of statements", adding that, "Now you could put these inside a computer and see a fault tree emerging in seconds."
It is worth noting at this point that NASA recently got involved in the rescue of the trapped miners in Chile, which was conducted flawlessly, but was kept out of dealing with the oil leak in the Gulf of Mexico, which was managed less well. When asked about the prospects of commercial space flight, Kranz thought that it would be, "Another decade before commercial space flight becomes viable and reliable", and predicted that this would come to pass when customers could go out and buy insurance.
As regards returning to the Moon and going to Mars, they said that in 2005, Congress approved a $9 billion program called 'Constellation', which was to be a, "Step by step process to go back to the Moon to do some serious exploration", to be followed by a 'Program to get to Mars'. However, President Bush did not approve the funding and President Obama has not approved it either.
Kranz lamented that, "Somebody will go to Mars but they will not be Americans", and added that if the programme had been approved, "You would continue to challenge people to develop new technologies." Since NASA still does much pioneering work on computer simulations of both mission scenarios, things going wrong with aircraft and the behaviour of parts, we took the opportunity to ask various people at the event about advances in simulation of more mundane situations, particularly those involving welded structures.
This particular concern arose from a lecture we had attended in the UK, given by Dr Robert Baker, an independent consultant who used to be in charge of metallurgical research at TWI. He revealed that despite more than half a century of research, welds in pipelines and major constructions were still cracking as a result of picking up minute amounts of hydrogen during the welding process, and, "The same questions are being asked and the same mistakes are being made as thirty years before."
Stephen Endersby product manager, simulation products for SolidWorks said that the weldment advisor in its Simulation Professional software is not based on finite element analysis, but looks at the stresses in a joint, and then looks up EN and ASTM tables. However, he said that one of their goals was to increase the intelligence within all their software, and advise users of possible problems, such as the potentially very low fatigue limits of load carrying fillet welds.
This was amplified by Austin O'Malley, the company's vice president of R&D who said, "We want to gather information as the user builds the model, and warn of possible problems", adding that two big steps forward are the dashboard advisor on sustainability issues, and the introduction in the 2012 edition of a dashboard advisor on costs.
A fascinating paper was delivered at the event by Dr John Oliva, mechanical design analysis and simulation group leader for the National Superconducting Cyclotron Laboratory on, "Doh! Ten ways our simulations have fooled us." In this, Oliva admitted: "I have been fooled by my computer many times", and when challenging his audience as to how many would admit such things had happened to them, found that most were willing to own up to the fact that they too had suffered such problems.
Dr Oliva's list included a modelling of vibration, where the model was cut in half because the vibrations were assumed to be symmetrical, but they were found not to be, and a thermal study which showed an even response in theory but substantial deflections in practice, which arose from minute thickness variations in real world manufactured parts.
In another case, a beam deflection calculation was way out because of a misunderstanding in whether the ends of the beam were held rigidly or free to move, while a whole series of erroneous predictions came out of choosing insufficiently small step sizes, missing important changes, resulting from efforts to reduce required computation times.
SolidWorks 2012 – predicted highlights
The most significant advance in SolidWorks 2012 in our opinion, is going to be the costing tool. Developers have tried to offer costing tools before, but they have usually required a large amount of data input on the part of the user. But this one, we are told, is, "Based on valid data that we have pulled from the market", and so will be able to offer manufacturing cost information, "Out of the box", while a "Template construct will allows users to add new values."
All cost data can be automatically captured for reports. There are to be no major changes to the core modelling facility because, "There have not been a lot of specific requests in the modelling area", but there will be specific improvements in sheet metal modelling, to ensure correct flange lengths and positions after bending although, "There will still be ways of coming up with designs that cannot be flattened and made."
A new equation editor will allow the creation of more complex equations and an automatic solver will put them in the right order, although this feature can be turned off if desired. Other important features will include the ability to keyword search for commands – not everyone can remember where icons are for commands they do not often use. It will be possible to re-sequence balloons and attach them to magnet lines, and centre marks will be able to be added to an entire view, after completion.
Other features mentioned include: a motion optimiser, a large design review mode and in response to popular request, a feature freeze facility, the ability to do complete uninstalls, the clearing of memory when a file is closed, and dual monitor support, so that a design can span two displays.
Yet more rapid prototyping and short run reduction
With rapid design comes the need to rapidly prototype parts either to evaluate them visually or to try them under service conditions. John Kawola, the CEO of Z Corporation commented to us that, "A lot of our customers are using rapid prototyping as a sales tool – many people do not connect with an image on a computer screen – they want to see something they can hold."
In addition to their established range of machines producing hard, coloured, visual representations of designs, the new 'ZBuilder Ultra' makes usable plastic parts with a tensile strength of 43 MPa, by using Digital Light Processing (DLP) to solidify a liquid photopolymer. Stratasys has brought out a Fused Deposition Modelling machine under the 'Dimension' brand name for $14,900.
At the same time, Katherina Hays of 3D Systems showed the company's new 'V-Flash' personal 3D printer that can be used in a design office and produces hard prototypes with good, paintable surfaces. Objet has a new, water clear material and an ABS material that can be made to produce shears that one can cut with. It also has a 'Vero White Plus material that can be used at up to 60°C or 80°C, "With a bit of treatment", which turned out to be a, "Few minutes in an oven, and which is also less prone to humidity absorption.
Richard Scherer, regional sales manager for Envisiontec told us more about their DLP process which he said is, "Similar" to stereolithography (SLA) but with visible light, which is directed by a Texas Instruments micro mirror chip, similar to those found in projection systems. It builds in voxels rather than layers, and it is possible to control the grey scale of each voxel. It is possible to make prototypes with walls down to 0.2mm thick.
Resins available include polypropylene and ABS, wax filled materials for investment casting, and medical grades for skin touch, such as the rapid manufacturing of hearing aids to suit individual ears. Their 'E-shell 200' series of materials have a heat deflection temperature of 200°C. For many parts, serviceable prototypes can be milled or otherwise produced in less time than it takes to make a prototype by one of the additive processes. Roland makes benchtop milling machines that interface directly to CAD work stations.
Tony Holtz of Protolabs showed us how they have improved their rapid moulding service to include internal undercuts, made using inserts in moulds, and how their 'First Cut' service is being extended to new metals to include stainless steel, brass, magnesium and titanium.
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