CAD

May 2000

Design Application

Moving into the third dimension

Design office managers must introduce a culture change when they 'upgrade' their office from 2D to 3D CAD. Lou Reade reports

Design is about the power of imagination. CAD does not turn a poor designer into a good one, but it does help a good designer to work faster and more efficiently.

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Somewhere in the UK there will be a design office that has not even heard of 2D CAD – or at least refuses to use it. There, hunched over an antique drawing board, are designers of complex parts who could save a great deal of time and money by using CAD. The most widely used package, worldwide, is still Autodesk's 2D CAD system AutoCAD. But cheaper and more user friendly 3D packages are offering the designer even more efficiency, flexibility and visualisation. But introducing 3D CAD to designers who are steeped in a 2D culture can be as difficult as the initial process to replace drawing boards with 2D systems.

Deciding to introduce a 3D system is easy; the hard part is choosing one. There is a seemingly limitless supply of not only packages, but also vendors who sell and install them. Geoff Hall of the Computing Suppliers Federation, which represents CAD vendors, says that it is crucial to avoid buying a system based on the 'wow' factor. He recommends taking an 'engineering approach'. "The most important thing is to know what you want to achieve," he says. "Don't look at buzzwords. Identify an improvement gap – know what it is that you want to improve."

He suggests sending a questionnaire to likely vendors, asking what their systems are capable of. "You can then choose two or three to chase seriously. That's when you get the team together. Don’t organise demos from 20 different vendors." This filtering process will, he says, ensure that you end up buying a much better product without wasting the time of the whole design team. "A really good solid modelling package costs around 5,000," he says. "The hardware to run it on will cost around the same, so you can get a superb system for 10,000."

He is convinced that 3D CAD has a crucial role to play in manufacturing. "It allows you to shorten lead times and time to market," he says. "There's also no need to re-input data." Despite this, many design offices run on 2D only. "Many people still use 2D," says Hall. "When they want parts made, they send 2D drawings." He suspects that traditional attitudes are preventing the use of 3D CAD spreading more quickly. "Conventional wisdom says that 3D systems are expensive and difficult to use," he says. "That's not been the case for more than two years, but that hasn't filtered through to senior management."

Cost is an important factor in this – though Hall suggests it should not be at the top of the list. "It's not a case of getting the lowest price," he says. Newhaven-based Cash Bases is a case in point. It manufactures the drawers that fit inside cash registers. The products are custom-built and produced in high volumes and small batches. But the growing number of products made by the company – more than 13,000 at the last count – means it must streamline the way it works.

"We've used 2D CAD for 12 years and now we've outgrown it," says managing director Hugh Burnett. "Every time we modified a design we had to go back to a host of drawings and change them all. Sometimes holes and edges don't quite line up. It's a challenge to get it right in 2D. Changes take a long time." The answer was to take the bull by the horns and introduce 3D CAD. The benefits of streamlining and efficiency were obvious to the company. "It might take between a week and 10 days to make the changes we needed using 2D," says Burnett. "With 3D, the computer does it all for you." The company spent around nine months assessing the benefits of various 3D packages, not least because of the number of packages on offer.

"We looked at lots of packages," says Burnett. "One of the difficulties in this market is that there's a lot of 'leapfrogging'. What's best today will quickly be overtaken by somebody else's next release. Eventually you must put a peg in the ground and say 'This is right for us'." Cash Bases eventually bought 13 seats of SolidWorks through vendor NT Cadcam. While the 70,000 order is hardly a revolution for SolidWorks, it is significant for a company like Cash Bases. And the company could have spent a lot less.

"Some of the options we considered were 50 per cent cheaper," says Burnett. "But we chose SolidWorks for good operational reasons: it was the only package we saw with bi-directional relationships. We could start from a finished product and unfold it, or start from our drawings and build a product. Many of our designs have been created using different systems and software. SolidWorks lets us take those details and create assemblies and solid models that we can modify and change back."

But he realised that introducing such a new system was not going to be easy. "It's not easy to get people who have spent 10 years using a 2D system to suddenly think about a new approach," he says. "The change from 2D to 3D is very much a cultural change for designers. You need to get everybody onside." There are other ways of ensuring minimal friction during the transition. Keith Goundry, a project manager at Hull-based boiler manufacturer Caradon Ideal, says that running old and new systems in parallel can lead to temptation.

"As soon as we got our new 3D system we transferred all our existing data across to it and got rid of the old system," he says. "If you don't do that, people who don't like change will tend to stick with what they know. Two years ago, the company threw out its 2D package and installed 19 seats of SDRC's Ideas software. "The main advantage of 3D was its ability to link directly to manufacturing equipment such as CNC machines," says Goundry. The whole manufacturing process has been shortened, he says. Where once, Caradon would have made wooden models to show clients, now it generates a 3D model or rapid prototype in a fraction of the time.

And despite the advantages, there is a definite learning curve. "One of the most difficult things was data management, " he says. "Keeping control of all that data is very hard. You don't realise this during demonstrations." But Caradon may go even further. While the Ideas software has 2D capabilities, Caradon is considering getting rid of 2D altogether. "We use 2D mainly for checking purposes," says Goundry. "Manufactured parts are sent for inspection along with a 2D drawing, in order to check tolerances. We're looking at the possibility of annotating the 3D drawings with crucial dimensions."

Price points

Robin Masterson is technical director of Bulgin, which manufactures electrical components such as connectors at its factory in Barking, Essex. Two years ago, his company introduced 3D CAD to the design office. "We now start concept design using 3D," he says. "Traditionally, you would do 2D layout and then look at it in 3D. It allows you to visualise the product much better." Bulgin uses Parametric's ProEngineer – and might have introduced it earlier but for the initial price.

"Four years ago, Pro/E cost 25,000 per seat, which was too expensive," says Masterson. "But later they brought out PT Modeller for the PC. It was like Pro/E's little brother and it cost 2,500. The move to NT and the PC was crucial." Masterson was initially worried that his design team would not take to the new 3D regime: "I got all the designers together then told them how the system should be used. I sat back to wait for the resistance but there wasn't a whisper."

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