29 August 2019
LK Metrology has announced its 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 new range of CMMs has been introduced offering high accuracy and repeatability in a compact footprint. Manufactured at the company’s UK plant, 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.
ALTERAC is equally at home in an inspection department or on the shop floor, especially as pneumatic mounts isolate the CMM from nearby sources of low frequency vibration such as large machinery. The CMM controller may be either stand-alone, or integrated into the machine base with an arm mounted monitor and keyboard, providing the customer a choice that best suits the installation site. 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, 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 free-form surfaces. ALTERAC measuring machines are able to 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, all of which are fundamental to delivering high accuracy measurements. Such is LK’s confidence in its design methods that it offers an unparalleled 10-year guarantee covering dimensional stability.
All guide-ways use 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.
All LK CMMs use ceramic for the moving bridge and spindle offering more than three times the stiffness of aluminium yet only one-third heavier by volume, resulting in higher machine acceleration and speed. LK claim ceramic does not stress-relieve like aluminium, leading to better long-term dimensional stability. The thermal expansion coefficient of ceramic, which is similar to that of granite but four times lower than aluminium’s, makes the structure highly resilient to thermal movement; moreover, ceramic is three times harder than aluminium, so is more resistant to abrasive wear and indentation states LK.
ALTERAC is available with LK’s powerful CAMIO8 DMIS-based, multi-sensor software enabling programming and measurement based on 3D CAD data and comprehensive reporting.
Source: Metrology News