Cobra Watertech, based in Krugersdorp, manufactures a comprehensive ranges of plumbing fittings. This includes plumbers' brassware such as unplated brass valves and connectors, chrome plated taps and mixers and high value-added valves used in geyser control, pressure safety, metering and flushing.

The Unigraphics software has been invaluable in Cobra Watertech's manufacturing process. The company makes use of a 5-axle CNC machine. One of the advantages of using 5-axle machining is the ability to machine a workpiece in its entirety from one reference face. The reference face is prepared and then clamped. The workpiece is then cut without breaking down the setting. Intelligent software is needed to determine the tool path so that all five axles function simultaneously.

The Unigraphics Design and Manufacturing Software is also used in three main areas of Cobra Watertech's design process, the first area being product design. New products unique to Cobra Watertech are modelled from prototypes, sketches or drawings of the product. Cobra can also produce custom-made products where the Unigraphics Software is used to model products from the sketches and specifications provided by clients.

Likewise, existing products are modelled when the need arises to manufacture tools and when a product range is upgraded.

Tool design is the second main area in which the software is implemented. There are four main categories of tools used in the manufacturing process, namely casting moulds, die sets, form drills and form clamping for machining. Other design processes include the modelling of machine parts, custom-made machines and gauges.

The third area where Unigraphics Software is used is in the creation of tool paths. On the one hand, tool paths are created for the cutting of casting moulds and die casts with a CNC milling machine and on the other hand, tool paths are created for wire sparking. Cobra Watertech is also in the process of creating tool paths for its CNC lathes with the CAM ability of Unigraphics.

According to James Bruwer of Cobra Watertech1s Process Engineering Division, the Unigraphics Software adds particular value to its product range's master models. "Firstly, the software makes it unnecessary to re-create geometry that already exists and the quality of models is also enhanced due to the fact that drawings cannot be misinterpreted. Mistakes are also minimised when the same geometry is used in different phases and levels of tool design.

"The Unigraphics Software also provides for shorter lead times. Market pressure demands that products are released in the market in the shortest possible time. The financial benefits involved in shorter lead times are self-evident."

The Unigraphics CAD/CAM Software is, however, not only used in maintenance of existing processes, but also in the creation of new capabilities. One of Cobra Watertech's success stories is the ability to create a 3D split line. Says Bruwer: "Most of our casting moulds and die casts have a split line on the xy level. Some of our products do however require a 3D split line. With the help of Unigraphics CAD/CAM capabilities we can now create a very accurate and stable 3D split line. It is no longer necessary to grind a product down into a more acceptable form."

Pre-empting problems is also an area where Unigraphics CAD/CAM Software is invaluable. Through electronic models, many problems that could not be detected previously, now show up before tools are actually manufactured at a great cost. At Cobra Watertech compositions are now modelled electronically and the fitting of different parts are then evaluated.

For more information: Esteq Design Technologies, 012 991 5570.