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Shaft grinding
October 1979, 1(4), 227-9). The flexibility versus frequency plots comparing synthetic granite and cast iron bed diamond turning lathes show the superiority of synthetic granite as a damping material. The 17F8A was developed originally to give improved machining of computer discs. It can produce a finish of better than 0.01/~m (0.4/~in) and is suitable for many precision facing'operations such as the machining of germanium optical components. Piston turning
A small piston ovalling lathe, the 100 POLr specially engineered for the oval and barrel turning of petrol engine pistons up to 100mm (4in) diameter, has also been introduced by Bryant Symons. The spiral grooves produced by the lathe's two cutting tools give a controlled surface with regular plates and troughs which ensure even oil distribution over the entire surface. Turned pistons therefore have a longer life than ground ones whose irregular finish leads to poor oil retention and increased wear.
Large deformations The symposium on Large Deformations, organised by the Indian Institute of Technology, New Delhi from 1 7 - 1 9 December 1979, had two sessions devoted to manufacturing processes. The effects of forming parameters, such as material properties, tool radius etc, on springback were reported by Singh. Ranganatha reported the experimental findings on the effects of gaseous environment (air, oxygen and argon) on tool wear (crater wear, flank wear and groove wear) in turning operations using a cementedtitanium-carbide tool. It was concluded that oxygen promotes groove formation and flank wear, whereas argon reduces them, but enhances crater wear.
Shaft grinding Multi-diameter shafts up to 1000mm long can be produced on a recently introduced, fully automatic, digitalcontrolled cylindrical grinding machine. The manufacturers claim that accuracy on diameters of + 1/~m, roundness to within 1/Jm and surface finishes down to 0.025#m can be achieved. The W.E. Norton-Morora MultiStepgrind, with a centre height o f 145mm diameter and accommodating wheels up to 200ram wide, has automatic gauging on all grinding diameters and is capable of both plunge and traverse grinding within the automatic cycle. The machine can be set for either straight approach operation, where only outside diameters are being ground, or for angular approach for
1. OMT (Optics) Ltd, Industrial Estate. Fakenham, Norfolk, UK 2. E. Leitz (Instruments) Ltd, 48 Park Street, Luton LU1 3HP, UK 3. Ferranti Ltd, Measurementand Inspection Group, Thornybank, Dalkeith, Midlothian EH22 2NG, UK 4. Renishaw Electrical Ltd, Gloucester Street, Wotton-under-Edge, Gloucestershire GL12 7DN, UK 5. Snow and Co Ltd, Andrew Street, Sheffield $3 8HD, UK 6. A.A. Jones and Shipman Ltd, Narborough Road South, PO Box 89, Leicester LE3 2LF, UK 7. St Etienne Machine-Outils, St Etienne, France
8. Agemaspark Ltd, Lincoln Road, Cressex Industrial Estate, High Wycombe, Bucks, UK 9. Indramat GmbH, 8770 Lhor/M, Postfach 505/506, FRG or G.L. Rexroth Ltd, Indramat Division, 49--57 High Street Droitwich, Worcs WR9 8EP, UK 10.Dean, Smith and Grace Ltd, PO Box 15, Worth Valley Works, Keighley, West Yorkshire BD21 4PG, UK 11. Bryant Symons, Northumberland Park, Tottenham, London N17 0TY, UK
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This is the SIP-600 Coordinate Boring and Milling Machine with manual data input and memory. It measures with a displacement uncertainty o f lpm. The metrological basis is provided by SIP grating scales. SIP, Societe Genevoise d'lnstruments de Physique, 8 rue des VieuxGrenadiers, CH- 121 I, Geneva 11, Switzerland
PRECISION ENGINEERING
PRE¢!, simultaneous grinding of diameters and adjacent faces. Varying diameters can be ground on the machine automatically, either sequentially or by profile dressing for grinding multidiameters in one plunge. Standard equipment on the machine includes stepping motor, infeed unit, and automatic table traverse, profile dressing, wheel wear compensation and sizing. W.E. Norton.(Machine Tools) Ltd, Dore House Industrial Estate, Orgreave Drive, Sheffield $13 9N R, UK
Transducer calibration
angular motion at the output to linear drive for the linear variable differential transducers. The rig was designed to the following specification: • Mechanical repeatability and accuracy of contact face to probe to be within 0.2/Jm over the working range for either direction of travel • Output of probe at any point in the working range to be correlated to the input position to within 0.2#m • Working displacement not less than 2mm • Initial hand setting accuracy of the probe to within 50#m (final adjustment can be effected electronically) • Contact face to probe to traverse in a straight line, within 10/zm of true line of travel, and face to remain perpendicular to probe axis within lmin of arc The rig is now in use and its rigidity and reliability have been demonstrated.
A calibration rig for linear variable differential transducers was designed by Michael Still while an undergraduate at Loughborough University, for which he received one of the five Design Council Molins Design prizes. The calibration rig relies on the Optical drill grinding use of simple flexure strip hinges to provide small yet precise angular movements. In this type of application, the single strip hinge is superior in performance to the well known cross strip hinge. The hinges were made using spring steel which was ground to form the flexure at the appropriate points. A 10:1 lever, which is supported by the hinges, converts the 25ram travel of a drum micrometer to the 2.5ram of the linear variable differential transducer. Slip gauges may be used as an alternative input, and provision is included for a Heidenhain digital length gauge to monitor the input. Flexure hinges are also employed in two parallel motions, one to convert the linear input to the angular motion of A built-in optical comparator that the lever, and the second to convert projects the drill image on to a viewing screen directly in front of the operator's eyes is the most important feature of the universal optical drill grinding machine from Practica. It features micrometer adjustment to the web grinding assembly and an adjustable magnifying glass unit. The drill can be aligned in seconds and is checked during the entire grinding process (hence minimum spoilage of the drill) and the projection assures optical accuracy of the sharpening. The machine can grind a range of drills from 0.3 to 25.5 mm diameter. Practica AG, 4410 Liestal, Waldenburgerstrasse 1, Switzerland or Gaston E. Marbaix Ltd, Marbaix House, Equipment for cartridge probe Bessemer Road, Basingstoke, calibration Hampshire RG21 3NT, UK
PRECISION ENGINEERING
Book Reviews Advances in Optical Metrology SPI E Proceedings Vol 153 Edited by N. Balasubramanian and J.C. Wvant
This volume is the proceedings of a seminar held in San Diego, California in August 1978 with the intention of reviewing "developments and recent accomplishments in optical metrology". It is split into four sections (corresponding to the four main sessions of the seminar), dealing respectively with "Laser Gauging", "1 nterferometry", "1 n-Process Metrology" and finally "Hybrid Optical Digital Techniques". On the whole the publication is very disappointing for several reasons: there is very little new described in the way of optical techniques (most of the topics covered have already been well publicised in the literature), in many of the papers the stress is very much on the data processing aspects and really more relevant to a seminar on computers and microprocessors, several of the papers have almost no relevance to optical metrology (at least in the sense that most people understand the term), and the actual technical content of the papers is in many cases very low, some being nothing more than sales literature. Sections 1 and 3 of the proceedings are the most relevant to the metrology of mechanical components, some of the topics covered being non-contact gauging, moird fringe contouring, measurement of surface finish etc. The remaining two sections deal almost exclusively with the testing of optical components. The engineer who is unfamiliar with the application of optical methods in metrology should certainly gain some benefit from reading these proceedings. Other readers will find it of minimum value. T.L. Williams Sira Institute Ltd, South Hill, Chislehurst, Kent BR7 5EH, UK Published by SPIE, PO Box 10, Bellingham, Washington 98225, USA, at $37 for USA, Canadaand Mexico, S29 for SPIE members end ~39 for overseas
231
A small piston ovalling lathe, the 100 POLr specially engineered for the oval and barrel turning of petrol engine pistons up to 100mm (4in) diameter, has also been introduced by Bryant Symons. The spiral grooves produced by the lathe's two cutting tools give a controlled surface with regular plates and troughs which ensure even oil distribution over the entire surface. Turned pistons therefore have a longer life than ground ones whose irregular finish leads to poor oil retention and increased wear.
Large deformations The symposium on Large Deformations, organised by the Indian Institute of Technology, New Delhi from 1 7 - 1 9 December 1979, had two sessions devoted to manufacturing processes. The effects of forming parameters, such as material properties, tool radius etc, on springback were reported by Singh. Ranganatha reported the experimental findings on the effects of gaseous environment (air, oxygen and argon) on tool wear (crater wear, flank wear and groove wear) in turning operations using a cementedtitanium-carbide tool. It was concluded that oxygen promotes groove formation and flank wear, whereas argon reduces them, but enhances crater wear.
Shaft grinding Multi-diameter shafts up to 1000mm long can be produced on a recently introduced, fully automatic, digitalcontrolled cylindrical grinding machine. The manufacturers claim that accuracy on diameters of + 1/~m, roundness to within 1/Jm and surface finishes down to 0.025#m can be achieved. The W.E. Norton-Morora MultiStepgrind, with a centre height o f 145mm diameter and accommodating wheels up to 200ram wide, has automatic gauging on all grinding diameters and is capable of both plunge and traverse grinding within the automatic cycle. The machine can be set for either straight approach operation, where only outside diameters are being ground, or for angular approach for
1. OMT (Optics) Ltd, Industrial Estate. Fakenham, Norfolk, UK 2. E. Leitz (Instruments) Ltd, 48 Park Street, Luton LU1 3HP, UK 3. Ferranti Ltd, Measurementand Inspection Group, Thornybank, Dalkeith, Midlothian EH22 2NG, UK 4. Renishaw Electrical Ltd, Gloucester Street, Wotton-under-Edge, Gloucestershire GL12 7DN, UK 5. Snow and Co Ltd, Andrew Street, Sheffield $3 8HD, UK 6. A.A. Jones and Shipman Ltd, Narborough Road South, PO Box 89, Leicester LE3 2LF, UK 7. St Etienne Machine-Outils, St Etienne, France
8. Agemaspark Ltd, Lincoln Road, Cressex Industrial Estate, High Wycombe, Bucks, UK 9. Indramat GmbH, 8770 Lhor/M, Postfach 505/506, FRG or G.L. Rexroth Ltd, Indramat Division, 49--57 High Street Droitwich, Worcs WR9 8EP, UK 10.Dean, Smith and Grace Ltd, PO Box 15, Worth Valley Works, Keighley, West Yorkshire BD21 4PG, UK 11. Bryant Symons, Northumberland Park, Tottenham, London N17 0TY, UK
230
This is the SIP-600 Coordinate Boring and Milling Machine with manual data input and memory. It measures with a displacement uncertainty o f lpm. The metrological basis is provided by SIP grating scales. SIP, Societe Genevoise d'lnstruments de Physique, 8 rue des VieuxGrenadiers, CH- 121 I, Geneva 11, Switzerland
PRECISION ENGINEERING
PRE¢!, simultaneous grinding of diameters and adjacent faces. Varying diameters can be ground on the machine automatically, either sequentially or by profile dressing for grinding multidiameters in one plunge. Standard equipment on the machine includes stepping motor, infeed unit, and automatic table traverse, profile dressing, wheel wear compensation and sizing. W.E. Norton.(Machine Tools) Ltd, Dore House Industrial Estate, Orgreave Drive, Sheffield $13 9N R, UK
Transducer calibration
angular motion at the output to linear drive for the linear variable differential transducers. The rig was designed to the following specification: • Mechanical repeatability and accuracy of contact face to probe to be within 0.2/Jm over the working range for either direction of travel • Output of probe at any point in the working range to be correlated to the input position to within 0.2#m • Working displacement not less than 2mm • Initial hand setting accuracy of the probe to within 50#m (final adjustment can be effected electronically) • Contact face to probe to traverse in a straight line, within 10/zm of true line of travel, and face to remain perpendicular to probe axis within lmin of arc The rig is now in use and its rigidity and reliability have been demonstrated.
A calibration rig for linear variable differential transducers was designed by Michael Still while an undergraduate at Loughborough University, for which he received one of the five Design Council Molins Design prizes. The calibration rig relies on the Optical drill grinding use of simple flexure strip hinges to provide small yet precise angular movements. In this type of application, the single strip hinge is superior in performance to the well known cross strip hinge. The hinges were made using spring steel which was ground to form the flexure at the appropriate points. A 10:1 lever, which is supported by the hinges, converts the 25ram travel of a drum micrometer to the 2.5ram of the linear variable differential transducer. Slip gauges may be used as an alternative input, and provision is included for a Heidenhain digital length gauge to monitor the input. Flexure hinges are also employed in two parallel motions, one to convert the linear input to the angular motion of A built-in optical comparator that the lever, and the second to convert projects the drill image on to a viewing screen directly in front of the operator's eyes is the most important feature of the universal optical drill grinding machine from Practica. It features micrometer adjustment to the web grinding assembly and an adjustable magnifying glass unit. The drill can be aligned in seconds and is checked during the entire grinding process (hence minimum spoilage of the drill) and the projection assures optical accuracy of the sharpening. The machine can grind a range of drills from 0.3 to 25.5 mm diameter. Practica AG, 4410 Liestal, Waldenburgerstrasse 1, Switzerland or Gaston E. Marbaix Ltd, Marbaix House, Equipment for cartridge probe Bessemer Road, Basingstoke, calibration Hampshire RG21 3NT, UK
PRECISION ENGINEERING
Book Reviews Advances in Optical Metrology SPI E Proceedings Vol 153 Edited by N. Balasubramanian and J.C. Wvant
This volume is the proceedings of a seminar held in San Diego, California in August 1978 with the intention of reviewing "developments and recent accomplishments in optical metrology". It is split into four sections (corresponding to the four main sessions of the seminar), dealing respectively with "Laser Gauging", "1 nterferometry", "1 n-Process Metrology" and finally "Hybrid Optical Digital Techniques". On the whole the publication is very disappointing for several reasons: there is very little new described in the way of optical techniques (most of the topics covered have already been well publicised in the literature), in many of the papers the stress is very much on the data processing aspects and really more relevant to a seminar on computers and microprocessors, several of the papers have almost no relevance to optical metrology (at least in the sense that most people understand the term), and the actual technical content of the papers is in many cases very low, some being nothing more than sales literature. Sections 1 and 3 of the proceedings are the most relevant to the metrology of mechanical components, some of the topics covered being non-contact gauging, moird fringe contouring, measurement of surface finish etc. The remaining two sections deal almost exclusively with the testing of optical components. The engineer who is unfamiliar with the application of optical methods in metrology should certainly gain some benefit from reading these proceedings. Other readers will find it of minimum value. T.L. Williams Sira Institute Ltd, South Hill, Chislehurst, Kent BR7 5EH, UK Published by SPIE, PO Box 10, Bellingham, Washington 98225, USA, at $37 for USA, Canadaand Mexico, S29 for SPIE members end ~39 for overseas
231