A range of CMMs has been introduced by British manufacturer LK Metrology offering high accuracy and repeatability in a compact footprint. Manufactured at the company's factory near Derby, the new ALTERAC machines are available in three sizes - 7.7.5, 10.7.5, and 10.7.7 - their respective X,Y,Z axis movements being 700 x 650 x 500 mm, 1,000 x 650 x 500 mm and 1,000 x 650 x 650 mm. Typical applications are likely to be found in the aerospace, automotive, medical and other industries with demanding inspection requirements.

The CMM control may be either stand-alone or integrated into the machine base with a keyboard on an arm at the side, giving the customer a choice that best suits the installation site. The latter option also facilitates relocation of the equipment once installed. The inclusion of Renishaw encoders with 0.05 μm resolution optical scales for high volumetric accuracy not only leads to outstanding metrology but also provides immunity to the ingress of contaminants.

Measurements taken with a touch-trigger probe at a series of points, ideal for acquiring information on dimensional accuracy, is increasingly being augmented by continuous-contact probing (analogue scanning) and laser scanning to allow high speed collection of data on complex freeform surfaces. The CMM structure has been optimized using computer aided solid modelling and finite element analysis, particularly within the bridge section, and is finely tuned to maximize stiffness, reduce vibration and provide smoothness of axis motion, all of which are fundamental to delivering high accuracy measurements. 

All guideways use LK-designed, low maintenance, pre-loaded air bearings of wrap-around design offering 3.5 times higher stiffness than standard air bearings. They run with a reduced air film thickness for low energy consumption and give repeatable measurement results, even at fast axis speeds. Friction drives provide smooth motion and exact positioning at continuously varying speeds, as well as zero backlash, overload protection and low maintenance costs. 

ALTERAC is available with LK’s CAMIO8 DMIS-based, multi-sensor software enabling programming and measurement based on 3D CAD data and comprehensive reporting.