Compact CMMs

Compact CMMs

November 26, 2019

LK Metrology

Brighton, Michigan – LK Metrology announces the new, AlteraC ceramic-bridge coordinate measuring machine (CMM) range. Using the latest metrology software, multi-sensor technology, and CMM designs, the compact systems are intended for demanding quality control applications.

The 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 700mm x 650mm x 500mm, 1,000mm x 650mm x 500 mm, and 1,000mm x 650mm x 650mm. Typical applications are to be found in the aerospace, automotive, medical, and other industries with demanding inspection requirements.

AlteraC is equally at home in an inspection department or on the shop floor, especially as pneumatic mounts isolate the CMM well from nearby sources of low-frequency vibration such as large machinery. 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 0.05μm resolution optical scales for high volumetric accuracy offers excellent metrology and immunity to contaminant ingress.

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 (analog scanning) and laser scanning to allow high-speed collection of data on complex freeform surfaces. AlteraC measuring machines can deploy all three types of sensor. Such flexible data acquisition boosts measurement throughput to avoid bottlenecks in the metrology department, provides a comprehensive awareness of component conformance, and meets today's manufacturers' requirement for a CMM that underpins concurrent engineering practices to speed time to market for new products.

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 to deliver accurate measurements. LK offers a 10-year guarantee covering dimensional stability.

All guideways use LK-designed, low maintenance, pre-loaded air bearings of wrap-around design offering 3.5x 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.

Ceramic for the moving bridge and spindle is more than 3x stiffer than aluminum yet only one-third heavier by volume, resulting in higher machine acceleration and speed. Ceramic does not stress-relieve like aluminum, leading to better long-term dimensional stability. The thermal expansion coefficient of ceramic, which is like that of granite but 4x lower than aluminum’s, makes the structure highly resilient to thermal movement. Moreover, ceramic is 3x harder than aluminum, so is more resistant to abrasive wear and indentation.

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