Premier Patterns used Delcam’s PowerMILL CAM system to produce an automotive master model from polystyrene foam; instead of using the more usual clay. Andrew Timmins, one of the Birmingham-based company’s owners, believes that machining from PS offers many benefits over the traditional approach.
“The first advantage is that PS foam is a cheaper material,” he claimed. “It is also easier and quicker to machine, more stable over time, and less prone to damage. It is easy to divide the model into separate sections, and chop and change various elements. Finally, PS can be treated with many different surface finishes to duplicate the appearance of metal bodywork and so can provide a more realistic model for manufacturers and potential customers.”
Mr. Timmins was able to demonstrate his alternative process on a recent project undertaken for Xtreme Automobiles, the developer of the X1 Concept low-cost, high-performance sports car. Xtreme was working to a tight budget and short delivery time, and so was the ideal client to persuade that PS was more cost-effective. The model of the complete car was cut on Premier Patterns 5m by 2½ m CNC machine. As with all the company’s machining, the programming was completed with PowerMILL.
Once the model had been viewed by the investors and the design had been approved, the same data was used within Delcam’s PowerSHAPE CAD software to produce master models and tooling for composite lay-up tools for the body panels. The software was also used to make the tooling for the dashboard and door linings.
Premier Patterns developed its skills in PS machining by producing sacrificial models for the casting of press tools, and by making patterns for welding jigs to be cast in iron or aluminium. For smaller parts, it also undertakes finish machining of the castings on a Cincinnati Sabre machine.
Like many other UK sub-contractors, Premier Patterns is now looking for other opportunities as lots of toolmaking work is going out of the country, both to countries with lower labour costs and to larger competitors in Germany. In addition to its automotive modelling work, it has machined a number of boat hull models and expects more work of this type in future. More unusual projects include manufacturing master models for furniture and props for theatre productions.
The company has used Delcam software since 1998. Mr. Timmins was the first employee to go on the training course and still does most of the programming. His fellow Director, Richard Irwin, also helps out but he is mainly responsible for supervising the shop floor.
“We had used manual methods for the first two years before moving to CNC machining,” remembered Mr. Timmins. “After looking around, we felt that the Delcam programs were the best software on the market at the time. A lot of our customers, plus many more companies that we wanted as customers, were using Delcam software. They all recommended the company, especially the quality of the support that was provided.”
“We used to do most of our modelling from drawings using PowerSHAPE but that is becoming less common,” he added. “We still need the software to add offsets to provide excess material on the castings and to split models into sections to minimise undercuts during machining. PowerMILL gives very accurate results, even on the large-scale models that we produce. In addition, it is very fast and easy to use.”