SP25M The world’s most compact and versatile scanning probe system The presentation explains how Renishaw designs its scanning systems, as well as providing comparisons of Renishaw’s solutions with those from other metrology suppliers. technology

SP25M brings exciting new benefits Two sensors in one! a SCANNING probe for form measurement and reverse engineering applications, capable of high-accuracy scanning across a stylus length range of 20 mm to 200 mm a TOUCH TRIGGER probe, using the versatile TP20 range of stylus modules Unmatched flexibility highly modular design permits the perfect measurement solution to suit the application the most flexible change rack system ever! Cost effectiveness low priced entry-level scanning kits with easy upgrade to include other system elements Flexibility through modular design

SP25M brings exciting new benefits Feature access total reach of nearly 400 mm is possible by using a probe extension bar five scanning modules each optimised for a specific range of stylus lengths stiff carbon fibre stylus extensions for excellent effective working length uses M3 styli up to 200 mm 100 mm extension In this video, an SP600M is scanning a feature deep inside a cylinder block, using a long stylus. Styli of up to 280 mm (11.0 in) can be used. The small diameter of the SP600 means that it can itself be inserted into many deep features, further extending the reach of the measurement system.

SP25M brings exciting new benefits Feature access - SP25M probe can be mounted on an articulating head means that many features can be accessed with fewer styli lower stylus costs shorter cycle times The SP25M’s compact size and low mass makes it ideal for mounting on a PH10M indexing head, enabling flexible access to numerous features around the part, without changing styli. Combined with module and stylus changing, this makes it the most versatile scanning system available.

System components - a highly modular concept SP25M - product naming ... SH25-1/2/3 SM25-1/2/3 SP25M Probe Body TM25-20 TP20 module PA25-20 PA25-SH FCR25 The SP25M supports three different scanning modules, each with gains and spring rates optimised to carry different length styli. By repositioning the ‘isle of Man’ spring, which provides the pivot point, relative to the readheads, and by adjusting the spring rates, excellent measurement performance can be achieved across a wide range of stylus lengths. The SM25-1 module carries styli up to 50 mm long The SM25-2 module carries styli between 50 mm and 100 mm long The SM25-3 module carries styli between 100 mm and 200 mm long

System components - a highly modular concept SP25M - as a TOUCH TRIGGER PROBE ... the probe body - would have the SM25-# scanning module replaced by the... TTP module adaptor (TM25-20) which directly carries any of Renishaw’s TP20 range of stylus modules: TP20 LF/SF/MF/EF TP20 EM1/EM2 TP20-6W The SP25M supports three different scanning modules, each with gains and spring rates optimised to carry different length styli. By repositioning the ‘isle of Man’ spring, which provides the pivot point, relative to the readheads, and by adjusting the spring rates, excellent measurement performance can be achieved across a wide range of stylus lengths. The SM25-1 module carries styli up to 50 mm long The SM25-2 module carries styli between 50 mm and 100 mm long The SM25-3 module carries styli between 100 mm and 200 mm long

System components - a highly modular concept FCR25 - the most flexible change rack ever from Renishaw … rapidly change between scanning and touch trigger mode to match the ideal solution to the application FCR25 is a triple-port unit, each port is easily configured to carry any system element of the system:  SM25-1/2/3  SH25-1/2/3  TM25-20  TP20 modules FCR25’s are mounted to the MRS to thus provide 3, 6, 9, 12, 15 etc port systems provides unmatched versatility !!! FCR25 PA25-20/SH SP25M module and stylus changing The SP25M is unique in that it supports both kinematic stylus changing and module changing using a single, modular rack system. Users can switch between a total of four modules - three scanning modules optimised for different stylus lengths, plus a touch-trigger module incorporating the TP20 sensor. Users can then select from a range of scanning styli, or from the full range of TP20 modules and extensions. The result is a highly flexible measurement system, that can provide the right combination of probe, extension and stylus to suit almost any dimensional measurement task. MRS

Design characteristics, performance and specification SP25M probe body houses the optical transducer ... isolated optical transducer uses proven IRED beams and PSD sensor technology (see later slide) Autojoint provides compatibility with all Renishaw’s multiwired heads and extension bars The SM25 scanning modules and TM25-20 touch trigger adaptor mount directly to the body via repeatable kinematic joint ultra-compact mechanism - fits inside Ø25 mm probe Autojoint Optical transducer system Kinematic mount for SM25-# or TM25-20 Compact dimensions - 25 mm diameter The SP25M is the world’s smallest scanning probe. The SP25M features a patented pivoting mechanism using an 'Isle of Man' spring (see diagram). When in contact with the part, the mechanism is extremely stiff, whilst its light mass requires very low spring rates to suspend it. When the stylus is in contact with the part, a rigid member connects the stylus tip with the measurement system, resulting in a high natural frequency. Unlike complex active probes, Renishaw's passive sensors do not require motors, independent dampers or locking mechanisms, all of which add to the mass and inertia of the sensor. Renishaw's unique design results in a high natural frequency and the capability to handle rapid changes in surface without hitting the bump-stops or losing the surface. A dynamically responsive mechanism, combined with tight machine motion control, allows Renishaw probes to scan at very high speeds. Another advantage of high speed response is that the maximum stylus travel of the probe can be smaller, thus reducing probe size and probe mass - all to the benefit of high speed scanning performance.

Design characteristics, performance and specification SM25 scanning modules house the motion system ... patented, pivoting mechanism featuring two diaphragm springs optimised to give very low inertia, low spring rates of < 0.6 N/mm and high accuracy over dedicated stylus range high natural frequency (rigid member) when in contact with the component ultra-compact mechanism - fits inside Ø25 mm probe 0.5 mm spherical radius measuring range ‘Isle of Man’ spring creates XY pivot point Compact dimensions - 25 mm diameter The SP25M is the world’s smallest scanning probe. The SP25M features a patented pivoting mechanism using an 'Isle of Man' spring (see diagram). When in contact with the part, the mechanism is extremely stiff, whilst its light mass requires very low spring rates to suspend it. When the stylus is in contact with the part, a rigid member connects the stylus tip with the measurement system, resulting in a high natural frequency. Unlike complex active probes, Renishaw's passive sensors do not require motors, independent dampers or locking mechanisms, all of which add to the mass and inertia of the sensor. Renishaw's unique design results in a high natural frequency and the capability to handle rapid changes in surface without hitting the bump-stops or losing the surface. A dynamically responsive mechanism, combined with tight machine motion control, allows Renishaw probes to scan at very high speeds. Another advantage of high speed response is that the maximum stylus travel of the probe can be smaller, thus reducing probe size and probe mass - all to the benefit of high speed scanning performance. Second spring allows translation in all directions

Design characteristics, performance and specification SP25M designed for “isolated optical metrology” IREDs in probe body reflect light off mirrors in scanning module back onto PSDs highly integrity performance - motion is faithfully translated to PSD’s non-linear outputs are compensated by sophisticated 3rd order polynomial algorithms no moving wires 2 PSDs (in body) detect stylus deflection 2 IRED sources (in body) IRED beams 2 Mirrors (in scan module) reflect beams back to PSD’s Body The SP26M uses a very different mechanism to SP80 and SP60, and a different optical scheme. Like those probes, however, the SP25M features isolated optical metrology, where the light sources (IREDs) and detectors (PSDs) are attached directly to the probe body, and therefore are able to measure the total deflection of the probe mechanism directly. The IREDs direct light onto two mirrors, mounted to the moving mechanism in the stylus module (the housings and kinematics are not shown for clarity). These mirrors can pivot and translate relative to the probe body and cause the reflected light patches to move on the PSDs. The XY location of both reflected beams are analysed and the resulting data can be used to compute the {x,y,z} deflection of the stylus. The relationship between the location of the reflected spots on the PSDs and the position of the stylus tip is complex and non-linear. However, Renishaw’s sophisticated compensation algorithms, featuring 3rd order polynomials to linearise the output, enable high accuracy scanning data to be extracted from this compact mechanism. The ISO 10360-4 test results show excellent performance for such a compact probe. Note: ISO Tij is the result generally quoted for scanning probes. It is the the total span of readings in the measured data set. Renishaw also quotes ISO Diff values - the maximum radial error from the calibrated perfect sphere to the measured values. Note that these results are for unknown path scans and are raw data with no filter applied. When a 60Hz harmonic filter is used, the Tij value for SP80 in this test fell to 1.3 microns. Other details for the ISO test: Scanning speed = 5 mm/sec Scanning deflection = 0.3 mm Total points taken = 2,281 Module Kinematic joint line between probe body and scanning module

Design characteristics, performance and specification 1. Design optimised such that max operating deflection results in highest performance of optical transducer 2. Swept area across PSD is optimised over specified stylus range 3. Reduced performance of sensor if longer stylus is used Specified stylus range Module lengths increase as spring gap changes to achieve desired pivot motion Why are there 5 scan modules to cover the stylus range? - traditionally, increasing stylus length leads to reducing accuracy SP25M addresses this characteristic … scan modules designed for optimum output from PSD sensors when using shortest stylus at max operating deflection (resulting in largest pivot motion/swept area over PSD’s by IRED beams - so giving best gain, resolution and highest accuracy metrology) whilst restricting loss of performance as longer stylus is used (by ensuring sufficient coverage of sensor is maintained resulting in low degradation of accuracy performance) if excessive stylus length is used, the pivot motion angle rapidly reduces (resulting in less swept area over PSD’s and non optimised transducer performance giving reduced accuracy)

Design characteristics, performance and specification Why are there 5 scan modules to cover the stylus range? - traditionally, increasing stylus length leads to reducing accuracy SP25M addresses this characteristic … the dedicated range for each stylus module also means that contact forces at the tip can be closely maintained (if we were to use excessive stylus lengths the force would reduce, reducing stability and accuracy) the fixed extension design of SH25-2/3 prevents use of illegally short stylus high accuracy data maintained as stylus length increases unique design of SP25M can result in 2-3 times better accuracy than SP600 Module lengths increase as spring gap changes to achieve desired pivot motion Specified stylus range 4. Design optimised to maintain a nominal deflection force of 60 g/mm across all three modules 5. Possible unsatisfactory contact force if longer stylus is used

Design characteristics, performance and specification Superior scanning performance ... accurate form measurement, even with long styli excellent reach capability ISO Tij m ISO 10360-4 test data Test conditions: CMM spec: 0.5 + L / 1000 Test speed: 5 mm/sec Controller: UCC1 Filter: None / 60 Hz Values: Unknown path 3.5 3.0 2.5 2.0 Filtered (60 Hz harmonic) This chart shows the results of a series of ISO 10360-4 scanning tests using a SP25M probe fitted to a PH10M head, with different stylus configurations. Two ISO Tij values are quoted for each stylus length: raw data and data that has been subject to a 60 Hz harmonic filter, designed to remove high frequency noise from the probe and machine position feedback systems. Three different scanning modules are used, each of which has been designed to work with a range of stylus lengths, with optimised gains and spring rates to deliver the best scanning accuracy: Module Stylus SM25-1 22 mm long, stainless steel stem, 3 mm ball - shortest scanning stylus SM25-1 50 mm long, ceramic stem, 5 mm ball - typical ‘short’ stylus SM25-2 100 mm long, graphite fibre stem, 6 mm ball - typical ‘long’ stylus SM25-3 200 mm long, graphite fibre stem, 6 mm ball - extreme length stylus Note that SP25M’s small size means that the probe itself can gain access to many deep features, extending the reach of the probe. 1.5 No filter (raw data) 1.0 Module/Stylus used: 21 = SM25-1 with 21 x 3 mm, SS stem 50 = SM25-1 with 50 x 5 mm, Ceramic stem 100 = SM25-2 with 100 x 6 mm, GF stem 200 = SM25-3 with 200 x 6 mm, GF stem 0.5 21 50 100 200 Stylus length (mm)

Design characteristics, performance and specification Noise comparison - SP600M typical plot

Design characteristics, performance and specification Noise comparison - SP25M has lower noise and better gain

SP25M The world’s most compact and versatile scanning probe system EMAIL QUESTIONS The presentation explains how Renishaw designs its scanning systems, as well as providing comparisons of Renishaw’s solutions with those from other metrology suppliers. technology