Renishaw says early adopters of its ultra-high-speed scanning system for coordinate measuring machines are achieving good productivity gains. At the heart of the Renscan5 system is the infinite-positioning REVO head. The system is being applied to complex parts that take long to manufacture.
One example is a jet engine blisk. The manufacturer had experienced a 922% throughput improvement, according to Renishaw. The inspection sequence comprises nine section scans of the airfoil profile, eight longitudinal scans of the blade, two scans of the root profile, and one scan of the annulus profile.
With conventional three-axis scanning at 10 mm/s, it takes 46 min per blade, or 22 h, 14 min for all 29 blades. With the EVO head, scanning takes place at the rate of 500 mm/s for a per-blade time of 4 min, 30 s—2 hr, 10 min, 30 s for all 29 blades.
“Besides major reductions in cycle times, Renscan5 and REVO make it possible to obtain far greater data point coverage,” said Denis Zayia, Renishaw CMM Product Manager.
“Faster inspection is especially vital on large, complex, high-value parts with many critical features,” he continued. “CMM [coordinate measuring machine] inspection can be a major bottleneck to efforts to speed throughput and gain lean efficiencies. Form measurement of complex parts and critical geometries for functional fits can demand many thousands of data points. Needing to produce and document parts to ever-higher precision, ever-tighter tolerances, manufacturers are looking to CMM speed for a solution.”
Conventional three-axis CMMs scan at rates of 5 to 15 mm/s to hold accuracy, according to Zayia. The aim is to avoid high acceleration and deceleration rates and rapid axis changes that can induce inertia errors, causing deterioration in measurement accuracy. “CMM inspection has been stuck in that time warp for over two decades,” he said.
The Renishaw was created in the company’s longest and largest development program. Renscan5 enabling technology encompasses a range of breakthrough five-axis scanning products that measure at up to 500 mm and 4000 data points per second while virtually eliminating the measurement errors normally associated with existing three-axis scanning systems.
A 3-D measuring device in its own right, the REVO head features two rotary axes—one in the vertical plane, one in the horizontal—to give infinite rotation and positioning capability. The measuring head performs synchronized Y- and Z-axis motion to quickly follow changes in part geometry during inspection routines, eliminating dynamic errors caused when moving the larger mass of a CMM structure. Where X axis motion is required for the probing routine, Renscan5 moves the CMM at a constant velocity along a constant vector as measurements are being taken, removing the acceleration/deceleration inertia errors incurred in conventional scanning.