REVO 5 Axis 3D Scanning
5 Axis Scanning Explained
In conventional 3D scanning measurement methods the CMM performs all the movements necessary to acquire the surface data. Acceleration forces induce inertia deflections into the CMM 3d scanning frame structure, which in turn induce measurement errors.
Metrology equipment system manufacturers have devoted years to develop techniques that reduce these dynamic errors, but there is an upper speed limit imposed by the machine and servo system stiffness, beyond which measurement cannot be taken with reliability. A stiff CMM frame is critical for effective scanning which is why aluminum frame CMMs make for a poor scanning solution and all-granite CMMs are the stiffest available.
Renscan5 breaks through this limit by using a continuous motion articulating head that moves simultaneously in two rotary axes as it scans. This technique allows the CMM to do what it is best designed to do - move at constant velocity in along a single vector while measuring. As the head is much lighter and more dynamic than the CMM it's able to quickly follow changes in the part geometry without introducing harmful CMM dynamic errors. This results in much faster surface 3D scanning speeds and hence much shorter measurement cycles. 5-axis scanning technology allows the user to achieve unprecedented levels of throughput while maintaining current levels of metrology uncertainties.
A Measurement Revolution!
REVO is the biggest step-change in measurement capability that Renishaw probes has ever introduced to the market and the coordinate measuring machine user has ever experienced. A true Measurement Revolution. Renscan5 enables unrivaled measurement performance and speed. Unlike conventional scanning methods 5-axis scanning uses synchronized motion of the CMM and head axes to minimize the machine's dynamic errors at ultra-high scanning speeds. Up to 500 mm/s is possible without any loss in accuracy.
CMM inspection time reduced from 55 down to 5 minutes, a 900% CMM productivity improvement when scanning two head gasket faces and five sections in each of eight cylinder bores typically takes 50 to 55 minutes. The Renscan5 REVO® system completes the same task in just 5 minutes.
5 Axis Scanning Techniques
Seven unique scanning techniques have been developed to maximize REVO productivity and to revolutionize the measurement of
complex geometry parts. The seven REVO scanning techniques are described below:
- CMM positions head above surface
- Renishaw probe moved onto gasket surface
- Head axes move to wipe the probe from side to side across the surface
- CMM moved at constant speed parallel to gasket surface
Blade Sharp Edge Sweep Scan
Around the Blade Scan
- Scan round the blade in one shot
- 5 axes industrial scanning where the head rotates as well as the CMM to allow one shot scan around the blade
Rapid Head Touches
Valve Seat Scanning
- The measurement process involves two helical scans, one on the valve guide bore and the second over the valve seat area. On the guide, a single helical scan is used with a typical pitch of 0.5 mm, at a scanning speed of 150 mm/s, while for the seat a single helical scan is carried out at a finer pitch of 0.1 mm and a faster industrial scanning speed of 500 mm/s. The latter scan utilizes Revo's adaptive scanning capability, which allows a single scan command to cover the areas above and below the critical valve seat surfaces.
The two measurement routines capture all necessary data about the valve seat and valve guide surfaces, which is then analyzed within a utility embedded in MODUS metrology software. A report is generated automatically that includes valve seat and valve guide features analysis including valve seat form error, run-out of the seat to guide bore axis, circularity of the seat at any specified height, form error of the cones, and circularity profile of the guide cylinder at any specified height. The unique REVO inspection method takes as little as 20 seconds per valve seat.
The Renishaw REVO is a dynamic new measuring machine head and probe system. It is the first in an upcoming range of revolutionary products to offer 5-axis measurement capability and is designed to maximize CMM throughput whilst maintaining high systems accuracy.
REVO uses synchronized motion and Renscan5 measurement technology to minimize the dynamic effects of CMM motion at ultra high measurement speeds. Using Renscan5, measurements are taken whilst moving the REVO head synchronously with the CMM. The unwanted effects of CMM dynamics at high 3D scanning speeds are removed. The use of the flexible RSP2 tip sensing probe system further adds to the systems' accuracy and flexibility. This removable probe system, used in conjunction with a low cost changer system, provides system flexibility as well as the potential of accessing new probe technologies in the future. A surface finish sensor is in development allowing the CMM to perform surface finish checks after a quick automatic sensor change.
3D Scanning and 3D Imaging are the other half of the equation in 3D Printing and Additive Manufacturing. With 3D printing the possibilities may seem endless, and maybe they are, but only if proven metrology principles are applied to measurement using 3D Scanning and 3D imaging. If you can’t measure you can’t ensure quality. Without quality assurance that 3D scanning can produce all manufacturing fails. To find out which of Wenzel America’s 3D scanning solutions can help you assure your quality in additive manufacturing contact Giles Gaskell at 248.295.4300 or email [email protected].