ISO-8956-1986.pdf

International Standard f 8956 0 * 4 this International Standard does not apply to such machines. 2 References IS0 230/l, Acceptance code for machine tools - Part 1: Geometric accuracy of the machine operating under no load or finishing conditions. IS0 1706, Acceptance conditions for general purpose parallel lathes - Testing of the accuracy. IS0 3655, Acceptance conditions for vertical turning and boring lathes with one or two columns with a single fixed or movable table - General introduction and testing of the accuracy. IS0 615511, Acceptance conditions for horizontal spindle capstan, turret and single spindle automatic lathes - Testing of the accuracy - Part 1: Machinable bar diameters greater than 25 mm. 3 Preliminary remarks The preliminary remarks in IS0 1706, IS0 3655 and IS0 6155/l are also applicable to this International Standard. Tests carried out on copying lathes shall be performed with the copying unit in position on the machine or integral with it. 4 Definitions 4.1 single-axis copying system: A system in which a com- ponent shape is produced by the motion of two slides, one of which is under servo-control from the contact of a stylus against a template while the other has a pre-set generally constant feed motion. In this case the displacement axis of the stylus is always parallel to the displacement axis of the copying slide. 4.2 two-axis copying system: A system in which a com- ponent shape is produced by the motion of two slides, both of which are under servo-control from me contact of a stylus against a template. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 22:47:07 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 8956-1986 (E) 5 Acceptance conditions and permissible deviations 5.1 Special tests 51.1 Lathes with single-axis copying systems The micrometer and dial gauge shall be mounted parallel with the servo-controlled axis under test. The tests shall be performed at the end of each stroke and midway along the copying slide stroke. uo. - 3.1 3.2 31.3 Diagram Object Assessment of repeatability of positioning Measurement of dead zone Measurement of sensitivity Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 22:47:07 MDTNo reproduction or networking permitted without license from IHS -,-,- IsO8966-1986 (El - Permissible deviation mm I in 0,005 0.02 o.ooo 2 in five repeats 0.000 8 Number of discrete movements of dial gauge: 10 10 for a 0,05 I 0.002 0 displacement of the micrometer Measuring instruments Dial gauge and template Dial gauge and micrometer Dial gauge and micrometer Observations Run the stylus rapidly down to the template, retract and repeat. Template and stylus profiles normal to copying axis. Mount dial gauge in cutting tool position. Mount micrometer against stylus. Rotate micrometer slowly towards stylus and back. Observe total movement of micrometer for zero movement of dial gauge. Rotate micrometer very slowly in one or other direction of copying slide stroke. Observe number of discrete movements of the dial gauge in specified movement of micrometer. Carry out tests in both directions. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 22:47:07 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 8866-1886 (El 5.1.2 Lathes with two-axis copying systems Each axis is tested independently. Micrometer and dial gauge shall be mounted parallel with the servo-controlled axis under test. They shall be performed at the end of each stroke and midway along the copying slide stroke. No. Diagram Object 22.1 Assessment of repeatability of positioning Measurement of dead zone 32.3 Measurement of sensitivity Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 22:47:07 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 8956-1966 (E) Permissible deviation mm 0,005 in five repeats in o.ooo 2 0,03 0.0012 normal to spindle axis 0.002 0 parallel to spindle axis Number of discrete movements of dial gauge: 5 I 5 for a 0,05 I 0.002 0 displacement of the micrometer Measuring instruments Dial gauge and template Dial gauge and micrometer Dial gauge and micrometer Observations Run the stylus rapidly down to the template, retract and repeat. Template and stylus profiles normal to copying axis under test. Mount dial gauge in cutting tool position. Mount micrometer against stylus in axis under test. Rotate micrometer very slowly towards stylus and back. Observe total movement of micrometer for zero movement of dial gauge. Rotate micrometer very slowly in one or other direction of copying slide stroke. Observe number of discrete movements of the dial gauge in specified movement of micrometer. Carry out tests in both directions. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 22:47:07 MDTNo reproduction or networking permitted without license from IHS -,-,- 5.2 Practical tests uo. Diagram and test piece dimensions Nature of test Dimensions in millimetres (inches in parentheses) This test is for machines with chuck- ing facilities only and without a tailstock. Machining three diameters, two shoulders and two tapers on cyl- indrical test pieces in chuck. D = 0.5 D, up to 200 mm max. (8 in max.) For single-axis copying machines : Pl D, = D - 1 mm (0.04 in) D3 = D, - 1 mm (0.04 in) D, = D - 20 mm (0.8 in) D, = D3 - 20 mm (0.8 in) For two-axis copying machines : Material : steel D, = D - 1,5 mm (0.05 in) hall be specified by ,he manufacturer. Checks to be applied 1) Taper surfaces shall be regular and without steps. 2) Measurement of deviation D - D, compared to template. 31 Measurement of deviation D - D2 compared to template. 41 Measurement of deviation of shoulder length A compared to template. T t Permissible deviation mm - iz 0,025 z!I 0.06 It 0.04 in - to.001 0 t 0.002 4 t 0.001 6 two-axis mm - + 0.03 IL 0,08 Ik 0.05 in z!L 0.001 2 * 0.003 2 Yk 0.002 0 Measuring instruments Micrometer, depth gauge and profile projector Observations ncludes the zffect of dead Lone twice. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 22:47:07 MDTNo reproduction or networking permitted without license from IHS -,-,- No. Diagram and test piece dimensions Nature of test This test is for machines which have facing capabilities. Facing profile consisting of three faces and one taper on a cylindrical test piece in the chuck. D = 0,5 D, or 160 mm (6.3 in) whichever is the smaller P2 For single-axis copying machines : H = 0,5 mm (0.02 in) For two-axis copying machines : H = 0,75 mm (0.03 in) D, = D - 40 mm (1.6 in) D2 = D - 90 mm (3.5 in) D, = D - 110 mm (4.4 in) D, = D - 150 mm (6 in) Material : steel - - ? D, = maximum swing over bed. 8 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 22:47:07 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 8966-1986 IE) Cutting conditions The axis of the emplate shall be set Derpendicular to the sxis of the machine. The inclination angle 3f the copying unit to the axis of the machine and the measuring pressure jhall be specified by the manufacturer. The facing shall be carried out from the outside diameter to the inside. Checks to be applied I) Taper surface to )e regular and Nithout steps. !) Measurement of depth of recess H :ompared to :emplate. 3) Check alignment ,f inner and outer ,ing faces (adjacent to diameters D and D,) compared to template. 3eviation should be Alowed only in a concave direction. l- Permissible deviation l- single-axis mm - If: 0,04 f 0,04 L in : 0.001 6 10.001 6 i two-axis mm - f 0,06 + 0,05 in - : 0.002 4 : 0.002 c Ii Measuring instruments Depth gauge, ;traight edge, ;lip gauges jbservations ncludes the !ffect of dead one. 9 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 22:47:07 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 8956-1986 (E) No. P3 Diagram and test piece dimensions Dimensions in millimetres (inches in parentheses) a) Minimum size test piece L = distance between centres = 200 (8) min. D= L/4 C = D - 10 (0.4) Material : steel b) Maximum size test piece L a 8Of3.2) 80(3.2) 15 20 15 20 15 (0.6) (0.8) (0.6) (0.81 (0.6) (0.8) (0.6) (0.8) (0.4) 4 1' A A A p 1 Cl ', - - ,L- k 8 ' '- 8 v t - L = distance between centres = 500 (20) max. D = L/5 C = D - 10 (0.4) Material : steel Nature of test This test is for machines which pro- duce shaft-type workpieces and is used instead of test Pl . For single-axis copying machines : X = D - 1 mm (0.04 in) For two-axis copying machines : X = D - 1,5 mm (0.06 in) Test pieces for machines of capac- ities between a) and b) may be suitably scaled. 10 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 22:47:07 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 6666-1966 (E) - Cutting conditions The workpiece shall be mounted between centres or in a work- holding device and supported by a tail- stock. The axis of the template shall be parallel to the axis of machine. The inclination angle of the copying unit to the axis of the machine and the measuring pressure shall be specified by the manufacturer. Checks to be applied 1) Taper surfaces shall be regular and free of steps. 2) All D diameters shall be within toler- ance, compared to template. * 3) All C diameters shall be within toler- ance, compared to template. * 4) All 90 shoulders shall be square, like the template or concave. 5) All 90 shoulder lengths shall be within tolerance, compared to tem- plate. T Permissible deviation single-axis mm - 2 0,025 + 0,06 +_0,025 f o&M in k 0.001 0 k 0.002 4 fro.001 0 tO.0016 two-axis mm - f 0,03 Tk 0,08 + 0,03 * 0.05 in - Ik 0.001 2 +0.003 2 Ik 0.001 2 f 0.002 0 Measuring instruments Micrometer, straight edge, slip gauges Observations Includes the effect of dead zone twice. NOTE - For the 2) and 3) checks, take into account the parallelism deviation between the template and the rotation axis of the machine. ? Variations of the intermediate diameters shall be within the deviations measured at the extreme ends. 11 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 22:47:07 MDTNo reproduction or networking permitted without license from IHS -,-,-