ISARA 400 ULTRA PRECISION COORDINATE MEASURING MACHINE
IBS Precision Engineering takes the measurement of large complex parts to nanometre level with multi-probe ISARA 400 3D coordinate measuring machine (CMM).
This important development has been achieved by increasing the measuring volume of its ultra precision 3D CMM by a factor of 40 - to 400 x 400 x 100 mm3 - a significant volume in view of the 45 nanometre (nm) 1D measuring uncertainty in all three directions.
Using three planar mirror laser interferometers, ISARA measures the position of an object on a table according to the Abbe principle: the functional point is in line with the measuring line to avoid errors in parallax. Positioned in one stiff frame with the probe, the three planar mirror laser interferometers have their virtual intersection point coinciding with the measuring point of the probe
The product table - made from Silicon Carbide (SiC) for its stiffness and thermal stability - is placed on a mirror table that can be moved in X and Y directions over a granite plate using porous media air bearings. A monolithic block of Zerodur deposits the reflective coating directly onto three extremely flat surfaces to form the three mirrors; the mirror block assembly is directly connected to the machine and calibrated within it, allowing for both the flatness and the mutual perpendicularity of each mirror.
Furthermore, the metrology frame containing the three laser interferometers and the probe moves in the Z direction using air bearings, over a granite guiding surface. The interferometers always point to the centre point of the probe tip (fulfilling the 3D Abbe principle) while the metrology frame (also made from SiC) is stiff with no internal degree of freedom, avoiding the need for extra bearings.
The base frame consists of two granite guiding units - one for the X-Y system and one for the Z - joined to form a stable base frame. The air bearing-equipped direct drives for all three directions are each mounted separately from the part they drive.
ISARA 400 is fully equipped for ultra precision performance and user convenience. Thermal shielding prevents measurement errors because of differences in thermal expansion. Three vibration isolators counter disturbances due to environmental vibrations while automated product handling prevents damage to critical parts that could be caused by manual operations. The machine comes with a separate Abbe probe alignment tool and a camera for measurement visualisation - especially useful during product alignment – in addition to dust protection and acoustic insulation.
IBS PE’s Triskelion ultra-precision touch probe will be initially implemented in the ISARA 400. Its design addresses the problems associated with most conventional probe systems: measuring uncertainty, probing forces and probe tip being too large. An AFM, a non-contact probe or optical probe, can also be implemented in the machine.
For all axes, the 1D measuring uncertainty is 45 nm, whereas the full-stroke 3D measuring uncertainty totals 100 nm. ISARA 400 can be used, for example, to measure large, free-form optic components. The large measuring volume, in conjunction with the automated product handler, allows the use of trays containing several products to be measured in one run.
For more information, please download our Isara 400 brochure:
