Measuring up to the challenge

Assembly Automation

ISSN: 0144-5154

Article publication date: 1 September 2004




(2004), "Measuring up to the challenge", Assembly Automation, Vol. 24 No. 3.



Emerald Group Publishing Limited

Copyright © 2004, Emerald Group Publishing Limited

Measuring up to the challenge

Measuring up to the challenge

Latest Aberlink co-ordinate measuring machines feature maxon motors and tachos

Keywords: Measuring instruments

Across the full spectrum of manufacturing industry, a key factor in maintaining efficient productivity is the ability to assess the shape and dimensions of components – quickly, accurately and economically. Meeting this challenge is leading co-ordinate measuring machine (CMM) maker Aberlink, which has turned to maxon motor to supply the necessary drives (Plate 2).

Plate 2 An Aberlink CMM is seen here measuring a cylinder head from a car engine. The machine's cover has been removed to show the maxon motors (circled)

While sophisticated digital encoders are becoming the norm in many high-precision electronic systems, Aberlink is unusual in preferring the more “traditional” DC tacho approach to speed control.

Tachos do in fact have an important operational advantage over digital alternatives in this application. The signal from a digital encoder come in pulses, and at slower speeds the blurring effect of the gaps between these pulses becomes much more significant. By contrast, a tacho's signal always gives a true picture of the motor's speed, which is particularly useful when it comes to fine control of slow movements. A digital unit capable of such high resolution would be prohibitively expensive.

The Aberlink machines, using air bearings, are virtually frictionless. This can create special motion control problems and the true speed feedback from an ironless tacho is essential to guarantee stability. maxon tachos are particularly sensitive thanks to their unique ironless coil, which takes up very little of the motor's torque.

The automotive and aerospace industries are among the biggest customers for these measuring devices, which are essential in inspection of components. Elsewhere they have many uses – in quality control of goods, for example. Another application is in the computer-generation of mould tools for new products.

For very small, thin or flexible items, where contact with the measuring machine would create a problem, Aberlink has developed a camera system which allows a non-contact measurement.

For further information on maxon's products and services, contact: maxon motor uk ltd, Maxon House, Hogwood Lane, Finchampstead, Berks, RG40 4QW.

Tel: 01189 733337; Fax: 01189 737472; E-mail:; Web site:

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