Tons of Precision

PMT Machines in India inspects high-precision parts for wind turbines twice as fast

Despite the impressive dimensions of modern wind turbines, maximum precision in manufacturing is still a must. PMT Machines Limited, the leading manufacturer of machine tools and parts for power and traffic technology in India, therefore relies on measuring machines from Carl Zeiss.

The challenge: minimal tolerances

The rotor hub of a 1.5 megawatt wind turbine is two meters in diameter and weighs 7.5 tons. Nonetheless, it must still be manufactured with maximum precision. The maximum error from the perfect round form of the boreholes must be no more than 30 micrometers – not even 0.01 percent of the diameter of the boreholes of 95 and 34 centimeters. If the error exceeds this tolerance, the customer would immediately return the parts – replacing components when a wind turbine fails would be too expensive.

PMT Machines Limited has been manufacturing parts for wind turbines since 2006. In the beginning, the several-ton parts were measured manually in the production machine. However, the tools and machine attachments made the measurements complicated.

Solution: automatic measurement with an MMZ G

PMT Machines purchased an MMZ G in 2010. The measuring machine from Carl Zeiss measures the form, size and position of large parts with particularly high demands on precision. With the MMZ G, PMT Machines now relies on one of the most accurate inspection machines of this class in India.

The MMZ G meets the demands of Indian customers for an all-in-one system that completes all their quality inspection jobs in a single go and as close to production as possible, i.e. near the machines used to manufacture the part.

"We have already had very good experiences with another measuring machine from Carl Zeiss IMT," praises Chetan Bhavsar, General Manager at PMT Machines. The company has been using a PRISMO navigator for three years.

Benefit: 100 percent accuracy in half the time

Thanks to the MMZ G, PMT is able to fully comply with the quality demands of its customers. Indian wind turbine manufacturers supplied by PMT Machines are very satisfied with the increased quality and precision of the parts.

A key benefit is the considerably higher speed of the quality inspections. "In the past, a complete manual measurement took up to three hours; now it takes less than half as long," states Bhavsar.

About the company

PMT Machines Limited is the leading manufacturer of machine tools and parts for power and traffic technology in India. Headquartered in Pune, the company has been manufacturing machine tools for a wide range of industries since 1963, including the automotive sector. In 2006, the company added parts for the rail industry and power generation to its portfolio. Its factories produce components for gas, steam and water turbines, as well as for wind turbines.