B.S.A Custom Built CMM

ITP Group believes that the 7.3m high coordinate measuring machine it has built for Beijing Space Authority to measure satellites may be the tallest CMM in the world.

The company makes large scale CMMs for the motor industry, with truck makers among its regular customers. But, says founder and managing director Dick Turpin, it has also built up a business in making bespoke machines for sectors such as nuclear power and Formula One.

“Three years ago, we opened a small office in China, with the main purpose being to buy granite for our machines, but also to sell into China,” said Turpin.

ITP was approached by the space group to build a single CMM to measure small commercial satellites. Having delivered one machine in 2003, it was contracted last year to build a bigger one, with the possibility of two more being ordered later in 2006.

“The satellites are 6m vertical and 3m square,” said Turpin. The machines can measure all faces of the satellites with an accuracy of 0.15mm volumetric.

To accommodate the new machine inside its factory, ITP has had to dig a pit in its factory floor. It has also changed the fundamental design of the machine: where standard largescale CMMs have a bridge structure, ITP’s machines mostly have a horizontal arm extending from a column.

But for this huge machine, Turpin has designed one in which the “column” is a structure composed of angle plates with the arm coming through the middle. This, said Turpin, gives it “extra rigidity” and enables the tolerances to be achieved at full extension. A tapering design on the cross-arm also adds to accuracy.

The CMM has a Renishaw touch probe as standard and is also fitted with an indexable milling insert for light machining. Turpin says the combination of measuring and milling has been successful in recent years, especially in milling clay car-body models in prototyping for new vehicles. And it offers milling to many customers, with NC controls built into the CMM operating system.

Building CMMs for Chinese satellite makers might seem like a bit of a niche. But Turpin said since starting with the Beijing group, ITP has identified two other Chinese satellite makers which can now expect a phone call.

For further information on the latest ITP Group bespoke measurement and milling machines available, Contact ITP Group.