With a history of innovation, Renishaw will not disappoint at MACH, unveiling a new touch-trigger probe head that incorporates two axes, drawing on REVO, its scanning head. Andrew Allcock explains [Includes video content]
Touch-trigger probe and measurement technology specialist Renishaw (01453 524524) has a long history of innovation. Indeed, it only deals in patentable technology. So it is no surprise that, yet again, MACH will be the event at which it unveils yet another product that sets the benchmark (there'll be 12 new products on show all together, however, see extended web article).
The company expects this development, the PH20 touch-trigger probe head, to "transform inspection performance on a wide range of co-ordinate measuring machines (CMMs)".
The new head incorporates two rotary axes and draws on the REVO 5-axis scanning probe head technology, which was launched at a previous MACH exhibition, in 2006. Whereas REVO offered full contact scanning, the PH20 probe head offers unique 'head touches' for rapid touch-trigger measurement.
So, for example, it can measure holes/bores simply by employing the two rotary axes in the head, with the CMM frame remaining static. "The result is improved accuracy, repeatability, and significantly improved inspection throughput, with parts measured up to three times faster than current touch-trigger systems," emphasises Brian Gow, Renishaw's CMM marketing manager.
Image: The extra two axes allow the head to support position and touch, so-called head-touches, allowing rapid measurement of bores.
Video: Renishaw's PH20 brings new functionality to touch-trigger probing
The system also offers fast infinite 5-axis positioning to guarantee optimal feature access, while the ability to index the probe head can also increase the effective capacity of a CMM, allowing the probe to move clear of the part to be measured, explains Renishaw general manager Marc Saunders. It similarly allows for part misalignment and has a maximum reach of almost 200 mm.
NEW OR RETROFIT
The PH20 can be fitted to new CMMs or retrofitted to the vast majority of existing CMM touch-trigger installations. The PH20 is currently supported by CMM makers Wenzel (01452 728298), Aberlink (01453 884461), Dukin and Mora-AEH, while compatible I++ software includes MODUS (Renishaw), Aberlink 3D (Aberlink), Quartis (Wenzel), NeuroMeasure (Dukin), Open DMIS (Xspect), Capps & Edges (AAT), Rational DMIS (External-Array Software Inc) and AC DMIS (Mora-AEH).
While existing CMM programs can be used with PH20, although not providing the full benefit, CMMs must have Renishaw's UCC controller fitted. The head can be calibrated in a single position, with head orientation and probe position determined in a single operation and inferred for others, allowing subsequent measurement at any head angle. For demanding applications, feature-specific calibration can be applied, of course.
The PH20 probe head has an integral TP20 probe mount, offering immediate have access to a range of proven probe modules, providing a wide selection of trigger forces, directional sensing options and extensions to meet application requirements. The detachable modules provide crash protection and can be automatically changed using the MCR20 change rack. Companies with existing TP20 systems will be able to upgrade to PH20 and utilise their existing modules (except the extended force module).
As Renishaw revealed details about the PH20 ahead of MACH 2010, Mr Saunders offered, enigmatically, that REVO and PH20 are "not the end of the story", so more in similar vein can be expected, quite clearly.
REVO BENEFITS SUBCONTRACTOR
At the same event, an application of the REVO scanning system at a small aerospace subcontractor was also highlighted. REVO has been an attractive development for larger, blue-chip companies, but installations have progressed slowly. Atherstone, Warwickshire-based ANT made its decision fast, adopting the technology to tackle an inspection bottleneck.
Set up in 1969 as a toolmaking company, today it is focused on the aerospace sector, having Rolls-Royce approval and host of other company or standard approvals, including AS9100. The 65-employee firm manufactures around 1,000 different parts, of which 85 per cent are delivered to aerospace firms to various tier levels. These include scale parts for test rigs as well as full scale flying parts. These include blades from 50 to 300 mm, plus rings into which blades are located and other large ring components.
Image: ANT's machine shop, busy making parts, mainly for aerospace customers, who are becoming ever more demanding, as regards inspection
Image: ANT makes parts such as these
An increasing requirement for post-process 100 per cent inspection, as opposed to operator level inspection followed by sample inspection, coupled with increased output from its modern CNC machines, saw a bottleneck arise in its inspection operations, reports technical director Alan Naylor.
The company had three elderly CMMs, but, even with latest technology, without an additional six or seven machines, the company would not be able to cope, he explained. "We were looking for something that would the make inspection faster, more accurate and would also deskill the operation." On the latter point, there are simply not enough skilled people to program available the CMMs, he emphasised.
The situation was brought to a head by a particular blade contract, and a new Metris CMM frame was retrofitted by Renishaw with its UCC controller and REVO head, complemented by its MODUS programming software, with the work being undertaken at Renishaw's Gloucestershire assembly plant prior to installation at ANT (Renishaw also carries out retrofits at customer sites).
ANT bought a Metris frame and Renishaw retrofitted the REVO package at its factory in Gloucestershire
Shaun Rowley, ANT's manufacturing and sales director explains the benefits: "Each of these blades used to take 2 hours to measure, now it can be done in 20 minutes. With this sort of throughput, I'm happy to agree to customer requests for 100 per cent inspection of most components. But that's not the whole story; this is a complex shape with a critical leading edge that the touch-trigger CMM just couldn't measure at all."
Image: Shaun Rowley holds one of the aerospace components that is now much quicker to inspect with Renishaw REVO technology
Prior to the new REVO-equipped CMM, ANT had to analyse the form using a projector technique to measure the shape – a long and laborious task. Now, the REVO system does the same job with a rapid profile scan, overlaying measured data onto the CAD design model and applying variable tolerances in different areas. "The ability it has given us is undoubtedly a key business advantage," Mr Rowley adds.
Rapid, deskilled programming of the new CMM is further aided by employing 3D models within MODUS and generating the programs by simply giving start point information, although many drawings are currently supplied as 2D drawings. However, the plan is now to train one of ANT's CADCAM team to also program the REVO inspection routines so that they have an overview of the whole production process. "He will then be able to consider all the implications for machining and inspection when creating the CAD model," adds Mr Rowley.
Image: Another view of the Metris CMM + REVO measuring a turbine blade component. So much fastr; much more accurate; and with reports generated to boot
An additional benefit is the ease with which reports can be generated, showing all measurements both in figures and graphically, Mr Naylor adds, something that hard gauging cannot support. And now that customers have seen this sort of capability, it is being demanded more and more, he offers.
The ability to automatically measure more parts in a single operation is also in line with companies such as Rolls-Royce's demands for non-manual measurement - any manual measurement requires gauge R&R to be applied to demonstrate capability with a report to back it up. And, as Mr Naylor explains, the uses to which REVO can be put are only limited by imagination, and this is one of the reasons that CADCAM personnel are being brought into the CMM programming frame, because they are "more forward-thinking" than traditional inspectors with a hands-on bias – "you have to approach things differently".
With the REVO-fitted CMM running round the clock, Mr Naylor says that the company would apply REVO measurement to all of its parts, but, clearly, the bottleneck in that regard is now CMM programming together with adequate numbers of inspectors versed in REVO use.
More Renishaw innovations at MACH 210
The UK company has a 90 m2 stand on which will be a Mori Seiki NMV machine tool, two CMMs and 12 new products. The company expects to take in excess of 500 enquiries at the show, reveals Marc Saunders.
• RMP40 - Ultra-compact radio transmission probe ideal for multi-axis and mill-turn machines. It uses unique frequency hopping spread spectrum (FHSS) probe signal radio transmission technology to allow automated job set-up and in-process measurement on all sizes of CNC machine tools.Click here for more details
• RLP40 - Lathe version of RMP40 featuring user-serviceable eyelid. Click here for more details
• OLP40 - Optical transmission lathe inspection probe replacing LTO2/3 series. Click here for more details
• Productivity+ probe - Multi-axis machine support enables creative process control on 5-axis machines. A key improvement is a new multi-axis option that allows more creativity and efficiency in machining processes, which, supported by Renishaw's high accuracy Rengage 3D technology-based touch probes and new ultra-compact radio probes, gives process engineers and machinists a wide choice of flexible process solutions. Click here for more details
• OMV Pro - Advanced CMM-style metrology with extended geometric dimensioning and tolerancing. Click here for more details
• AxiSet - Fast, automated health-check for 5-axis machine tools. a new cost-effective solution for checking the alignment and positioning performance of rotary axes. At MACH 2010, visitors will see that in just a few minutes, users of 5-axis machining centres and multi-tasking mill-turn machines can identify and report on poor machine alignments and geometry that can cause extended process setting times, as well as non-conforming parts.Click here for more details
• Resolute Linear - Absolute position feedback to 1 nm resolution at an incredible 100 m/sec. It is a true absolute optical encoder system that has excellent dirt immunity. Absolute position is acquired immediately at system switch-on, so the exact orientation of axis and motor commutation angle are known, without the need for a reference (datum) return.
• Resolute Angular - Angle measurement to 27 bit resolution at 36,000 rpm, with features as for Linear. Click here for more details about both linear and angular Resolute products
• REVO Valve Seat - 5-axis valve seat and guide inspection in just 20 secs per valve. Click here for more details
• MODUS Software - Updated 5-axis programming tools and powerful new customisable reporting. Click here for more details
• QC20-W - Wireless ballbar featuring volumetric assessment in a single set-up. A completely new design featuring a Renishaw-developed linear sensor and Bluetooth wireless technology, which also allows testing in three orthogonal planes through a single reference point. A single, simple hardware set-up means quicker testing and the ability to produce a representative volumetric measurement of positioning accuracy. Click here for more details
First published in Machinery, June 2010