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This parallel kinematic structure is a gaging system that combines speed, accuracy and flexibility. What’s more, it is engineered to be easy to use.
Although “Renishaw” (renishaw.com) is synonymous with probes used with coordinate measuring machines (CMMs), the technology company has just launched its own gaging system, the Equator 300.
It combines the best of both worlds metrology-wise:
• Like hard gages, it is fast and accurate
• Like CMMs, it is flexible and versatile
As for the speed, the programmable machine can obtain up to 1,000 points per second with its SP25 analog probe; it has a scanning speed of 100 mm/sec. It has a working envelope of 300 x 300 x 150 mm (X, Y, Z) and offers a maximum movement speed of 500 mm/sec.
As for the accuracy, it offers what is called a “comparison accuracy” of ±0.002 mm, with the comparison being made to a master part, and assuming that the part being measured by the Equator is fixtured to 1 mm relative to the master part. According to Renishaw, unlike the master part that’s necessary to establish the datum points for a hard gage, the master part that can be used for the Equator is a part that has been taken off the production line. This part is measured on a CMM, thereby establishing any feature variation from the CAD file for the part or to create nominals for the part. The calibration file created from that is then loaded into the Equator software and used as the master. One interesting aspect of this is that whereas the CMM may be in a temperature-controlled room away from the factory floor, the Equator can work right on the floor and because of the accuracy that can be obtained by the CMM under those better conditions, the Equator can be more accurate given that it is working with the data from the CMM. There is also the ability to quickly remaster parts in order to accommodate temperature variations on the factory floor.
The flexibility and versatility of the system are predicated on its design: It has a parallel kinematic structure that allows ready manipulation of the probe to access part features that might otherwise be difficult to reach. Additionally, the system can readily accommodate a variety of parts on its 305 x 305-mm fixture plates, which can handle masses up to 25 kg. Part changeovers can be effected in a matter of minutes, thereby making the system useful for both short-run and high-variety operations, as well as high volume production. There is a six-position stylus changing rack; the system’s SM25 stylus modules couple directly to SP25 CMM probes, so stylus configurations can be swapped without necessitating requalification.
What’s more, the structural design is inherently stiff to help assure measurement accuracy, even though it is moving the probe at comparatively high rates of speed.
Because the system is engineered for shop-floor operations, it is designed to be easy to use. For example, the controller is similar to that used for a machine tool. There are two software packages, the MODUS Organiser shop-floor system for operators that allows program execution but not modification and the MODUS Equator, a metrology package that allows programmers to develop and adjust DMIS programs; thanks to wizards, measurement programs can be generated without the need for specialist programming skills.
According to David Emmett, Renishaw business manager of CMM products, the system costs about $30,000. Which means that the Equator is not only fast, accurate, versatile, and flexible, but it is economical, too.
With some 20,000 systems out in the field, when FARO Technologies (faro.com) describes something as “the world’s most innovative measurement arm,” the fact that they’ve got that many FAROArms working certainly adds considerable credibility to the claim. They’re talking about the FARO Edge portable measurement arm that can be used for applications ranging from inspection to tool certification, from CAD-to-part comparison to reverse engineering. The Edge operates with tactile and non-contact probes, and it is engineered with a touch screen and an on-board operating system so measurements can be made without a need for an attached laptop.
The seven-axis arm comes in three sizes:
• 6 ft. with a ±0.0013-in. volumetric accuracy and 0.0009-in. single point repeatability
• 9 ft. with a ±0.0016-in. volumetric accuracy and 0.0011-in. single point repeatability
• 12 ft. with a ±0.0035-in. volumetric accuracy and 0.0025-in. single point repeatability
In addition to which, they’ve developed the FARO V4 Laser Line Probe that can be readily integrated with the Edge vis a multi-function, quick-change handle port. The V4 provides an accuracy of ±0.0014 in., a repeatability of 0.0014 in., a near-field effective scan width of 2.09 in., a far-field effective scan width of 3.94 in., and it takes 752 points/line, and offers a scan rate of 60 frames/second.
Other features of the edge include connectivity options (Bluetooth, WiFi, USB, Ethernet) and an ergonomic design for ease of use (the biggest arm weighs just 24.9 lb., and the counterweight setup—used for all the arms—makes manipulation smooth).
The FARO Edge provides the ability to readily perform dimensional checks thanks to its built-in touch screen and on-board operating system.
The HN-6060 from Nikon Metrology (nikonmetrology.com) is a non-contact, multisensor measuring system for fast, high-accuracy inspection of complex shapes, such as gears, closures, housings, and other prismatic parts.
Speed: Using the laser scanner, the machine is capable of obtain-ing point clouds at a rate of 120,000 points per second. (There is optional software, Focus Inspec-tion, that allows part-to-CAD inspection based on the point cloud information.) As regards accuracy, thanks to the deploy-ment of Nikon’s proprietary low thermal expansion encoder scales and other features, it is 1.5 + 4L/1,000 µm.
The configuration of the unit features a three-axis structure and a two-axis rotary table. There is a five-axis linear motor drive and control mechanism. The system has an orthogonal three-axis envelope of 600 x 600 x 600 mm. On the table the maximum diameter and height of the object to be inspected are 300 and 200 mm, respectively.
In addition to the laser scanner, there is an SFF (shape from focus) sensor. It uses active texture projection so that glossy surfaces or surfaces without surface texture (think of some molded components) can be precisely measured. What’s more, there is a TTL laser AF sensor, which has been deployed in the Nikon NEXIV VMR series CNC video measuring system, and there is the opportunity to use Renishaw probes and probe heads (PH1 fixed; PH10T indexing).
The Nikon HN-6060 is a multi-sensor—from laser to tactile—metrology system that facilitates the measurement of complex shapes.