Changing Mould Design SoftwareWithout Breaking Stride

Stet Engineering Ltd. is considered a pioneer of CAD/CAM software among Irish toolmakers, and began using its first system in 1984. The company was established in 1977 to make injection moulds for the many international companies that have begun manufacturing in Ireland. It has grown steadily and now numbers 35 people in a 2,000-sq-m facility in the city of Sligo. Recently, management recognized the company was approaching the limits of its software and decided to upgrade. In fact, it wound up making a complete change of systems.

"Our customers choose Stet because of our ability to manufacture high-quality moulds that accurately produce a wide range of shapes and contours," explains Stet's Alan Mooney. "Their products are becoming increasingly complex, which means that the tooling is more complicated as well." Mooney said Stet clearly saw that more powerful software was needed to remain more competitive. It was equally important to avoid disrupting work flow while the new software was installed and learned.

After evaluating a number of leading software packages, Stet decided on Duct CAD/CAM from Delcam International, Birmingham, U.K. There were a lot of reasons, but in terms of performance features, the most attractive was the capability Duct has in handling complex surface information. "It's a very powerful machining tool," says Mooney, "in fact, we can work totally gouge-free."

Stet installed two Duct stations. Mooney says 12 years of CAD experience surely made the start-up easier, but adds, "Having said that, the system is quite easy to learn for such powerful software." As if to prove that, Stet began the design of a mould for the housing of a new, battery-operated Hitachi drill less than a month after the installation.

Using the 2-D CAD file received from the client, Stet created the 3-D tool design file in Duct, the electrodes for erosion cutting, and the tool itself, all in substantially less time than needed with the older software. And Mooney says that the accuracy and overall quality assurance was improved at every step.

Much of the improvement, says Mooney, can be attributed to the difference between the former sequential process and the concurrent engineering now enjoyed. "We don't physically take drawings to the machine room and key in the codes anymore." Since Stet uses CNC machining stations, the ability to transfer the digital output of the design software directly to the cutting machine not only saves time but eliminates a place for errors to occur. The mould for the Hitachi drill is now making the ABS parts in a moulding shop near Dublin.

Stet is now well into a number of other projects using the Duct software. And all continue to be impressed by its machining strengths. As an example, Mooney notes how a roughing tool cannot do the small finishing work required in a complex tool. The Delcam software recognizes this, and being programmed with the information on Stet's machines and tools, it automatically selects and sends in a finishing tool to machine the feature that the roughing tool could not.