Solving a significant production bottleneck, the Renscan5™ 5-axis scanning system and REVO™ infinite positioning, 2-axis head are the first products to come out of the longest and most complex development program in Renishaw's 33-year history.
Renishaw believes Renscan5 and REVO ultra-high-speed scanning are a revolutionary metrology development, making possible advances in CMM productivity of a magnitude comparable to the initial automation of part feature measurement. They raise CMM scanning speeds to 500 mm sec — 20 times and more over conventional practice.
Renscan5 and REVO solve what has been a major production bottleneck for makers of complex, high-value parts requiring large numbers of data points for process control and quality verification. Ultra-high-speed scanning transforms measurement throughput, greatly reducing cycle times while simultaneously enabling greater data coverage (10 times faster data point acquisition) to meet tighter part specifications.
Unlike many breakthrough innovations, which require total changeover to new systems, Renscan5 and REVO can be universally applied to current OEM machines from multiple CMM makers and to upgrade performance of existing CMMs.
Renscan5 and REVO required the creation and integration of multiple technology innovations:
5-Axis Scanning
- Two-axis, infinite positioning head performs most of the work, minimizing CMM motion and associated dynamic errors.
- Allows CMM to move in a single axis at constant velocity or low acceleration in most routines. Avoids dynamic errors incurred in moving CMM at high rates of acceleration/deceleration, the previous limiter on scanning speeds.
- Proprietary error-mapping software compensates in real-time for a whole range of geometric, temperature, and machine dynamic errors.
- Second-generation UCC2 universal CMM controller with patented MoveScan™ software synchronizes, speeds, and smoothes motion between CMM and REVO head. MoveScan allows the machine to drive the probe to the surface of the part, in the shortest distance, by looking at go-to points ahead of time and blending moves into one smooth, continuous motion. This drastically reduces measurement times to raise CMM throughput.
- Head indexes on the fly, no delays. On-the-fly repositioning of head and stylus between part features shortens scanning time over indexing systems.
- UCC2 controller provides single processor, crucial to data management at ultra-high scanning speeds.
- UCC2 operates at 2 Khz update rate, gives the capability to collect 2,000 points/sec.
Low Mass, 2 Axis REVO Head
Infinite-positioning two-axis probe head – 360 deg of rotary motion in horizontal axis, 270 deg rotation in vertical axis – moves while measuring to infinitely adjust to the part surface. - Repositioning occurs continuously, on the fly, simultaneous with measurement. This differs from separate positioning and measurement steps with indexing heads which reposition incrementally (7.5 deg for Renishaw PH10) and then lock into new position, after which the CMM provides the measuring motion.
- Continuous rotation simplifies part programming.
- Direct-drive brushless motors (no gears) provide low-friction drive, smooth acceleration, and minimal interference.
- Hard-gold slip ring contact. The mechanism for transmitting drive, the slip rings are the only part of the head design with contact between moving surfaces, minimizing friction and wear; tested to 50 million cycles without perceivable degradation.
- Proprietary high-resolution 0.08 arc-second rotary encoders, developed and manufactured by Renishaw, deliver high positioning accuracy.
- Patented spherical air-bearings provide a very stiff metrology platform with high dynamic response and low-resistance/friction for high accelerations and fast changes in direction.
- On-the-fly measurement collects data at 6 Khz, (6,000 data points/sec), three times the processing rate of the UCC controller. Provides additional data that can be buffered and analyzed post process on selected part features, without taking up CMM time.
Laser-Corrected 2-D "Tip Sense" Probe
- Integrated miniaturized laser/receiver enables unique "Tip Sense" probe design employing new family of low-mass, hollow-tube styli. 2-D "Tip Sense" probe, the RSP2 is used for most REVO part scanning routines.
- Laser beam is directed from its source in the probe body, mounted in the REVO head, down the hollow stylus to a reflector at the stylus tip to accurately sense exact tip position. High speed and accuracy can be achieved because the light beam is not affected by gravity, inertia, or thermal effects.
- The laser provides detection/correction for controlled stylus deflection. Stylus is designed to bend under high acceleration and inertial forces, typically ~ 50 µm at the tip.
- Bending deflects the return path of the laser beam, which is received by a PSD (position sensing detector) also mounted in the probe body.
- Movement of the laser spot on the PSD is translated into measurement output and combined in software algorithms with head and probe geometry and CMM axis scale outputs, allowing exact stylus tip position in space to be derived on-the-fly during dynamic 2-D scanning.
- Hollow tube design provides ultra-low moving mass, just the stylus ball, and ultra-low scanning force to minimize wear and pickup.
- Tip Sense probes deliver 1 micron accuracy at 250 mm from axis of rotation.
- Range of stylus tubes provides probe reach to 500 mm.
- Enables innovative probing routines -- sweep scanning, zig-zag edge measurement.
3-D Probe
- RSP3 is mainly used for crank and disk styli applications.
- Based on PH10/SP25M probe technologies.
- Allows reach up to 250 mm.
Open Interface
- I++ DMIS open interface gives the UCC controller cross-platform compatibility with all major measurement software packages.
- Supports universal application to maintain user choice of CMM and software.
- UCCserver™ software developed by Renishaw to handle all I++ DME protocol communications.
Renishaw fundamentally believes that commercial success comes from patented and innovative products and processes. The company has long been a leader among technology companies in R&D investment, allocating 15% of annual income to creating and applying advanced and proprietary technologies to raising measurement precision.