3-D CAD cuts meter size

Hitchin, England--Smaller, more functionality, and lower production costs; these were the goals facing Siemens Measurements Ltd. when designing an electricity meter for the UK. Because current liberalization of the British electricity industry is sure to make the market more competitive, Siemens wanted a meter that would require minimal investment from regional electricity companies while providing an upgrade path for future requirements.

Designed with I-DEAS Masters Series from SDRC (Milford, OH), the resulting product measures less than one-quarter the size of traditional meters. Additional modules such as smart card and radio telemetry allow expanded functionality while an integrated installation switch, traditionally a separate item, reduces cost when connecting new customers.

Siemens reports that because the 3-D CAD program held tolerances so accurately from concept and prototyping through manufacturing, the company brought the meter to market in just 12 months with a 10% savings on the tooling budget.

"Using 3-D CAD modeling on this project has changed our whole design philosophy," says John Cowburn, project leader at Siemens Measurements. "While the initial design takes a little longer to produce, both the tooling and later modifications are faster and easier. It's also quite impressive to see the virtual model in 3-D," he adds.

After developing a 3-D concept model, Siemens incorporated feedback from prospective customers and generated prototypes directly from the 3-D data. Using the interface between I-DEAS and Vultrax (the circuit board layout software used by Siemens), the electronic subassembly in the system was brought into the 3-D model and the analysis capabilities allowed the engineers to verify fit and function.

"The zoom function in I-DEAS is particularly important," says Cowburn, "helping prevent overlapping or gaps--things that are not always apparent unless viewed ."

More than 100,000 meters have sold the first year; Siemens has since developed a European version.