UK-based CMM manufacturer LK Metrology has designed a new, more efficient air bearing and carrier, which the company now fits as standard to its Altera-C range of ceramic-bridge, multi-sensor CMMs. By significantly augmenting the pre-load on the structure, stiffness has been uprated without making the guideway thicker, leading to more precise motion control.

According to LK, the results are higher measuring accuracy, whether a touch-trigger probe or scanning probe is used, coupled with the possibility to increase speed of operation and raise inspection efficiency. The Altera-C machines, which are available in three sizes with measuring volumes of 700 x 650 x 500 mm, 1000 x 650 x 500 mm and 1000 x 650 x 650 mm, carry a 10-year accuracy guarantee covering dimensional stability.

In terms of speed, all machines now accelerate at 1900 mm/s2, representing an increase of 15% for the two smaller models and 20% for the largest model. Velocity is up by 38% across the product range to 720 mm/s. As regards accuracy, the maximum permissible measuring error on all machines is now 1.7+L/333 µm when measurements are taken of a feature L mm in length (between 18°C and 22°C), irrespective of whether a TP200, SP25, TP20 or PH20 probe is used. This performance represents length measurement accuracy improvements of 22%, 22%, 32% and 43% for the four respective probes, while maximum permissible probing error is also better, as is repeatability of measurements (by 15%) when using a PH20.

Optimisation of the pre-loaded, wrap-around air bearing configuration was feasible due to the inherent rigidity of LK’s ceramic guideway, which allows it to maintain structural integrity under extreme conditions.

For further information
www.lkmetrology.com