Used Wmw Guideway Grinding Machine for sale (65,079)

Condition: repair required (used), Year of construction: 1981, grinding length: 6,600 mm, grinding width: 300 mm, grinding height: 260 mm, table width: 550 mm, grinding spindle motor power: 52,000 W, We are offering this Göckel G 80 eL surface grinding machine, manufactured in 1981, which requires repair. Manufacturer: Gustav Göckel Maschinenfabrik GmbH D-6100 Darmstadt Machine type: G 80 eL Serial number: 6062 If you have any questions or would like more information, please feel free to send us a message or call us. Rcjdpfx Aszvqh Ujb Tof - Grinding length: 6600 mm - Width: 550 mm - Magnet width: 300 mm - Grinding width: 520 mm - Grinding height: 260 mm - Grinding height at right angles: 150 mm - Grinding motor: 52 KW Please note: the machine is delivered without a water tank. Pumps, hoses, and accessories are included.

Condition: used, functionality: fully functional, machine/vehicle number: 7085, Used universal cylindrical grinding machine Manufacturer: WMW Model: SU 315 x 1000 mm Equipped with internal grinding attachment Maximum workpiece diameter: 315 mm Maximum grinding length: 1000 mm Grinding spindle speed: 1340 rpm Rodpowl A H Defx Ab Tocf Workpiece speed: 22–500 rpm Longitudinal table travel: 5–1680 mm Table feed rate: 0.05–5 m/min Maximum workpiece weight: 300 kg Connected load: 12.5 kW Machine weight approx.: 5.8 t

Condition: used, functionality: fully functional, machine/vehicle number: 40/35-22, Price on request Used Gear Grinding Machine Brand: NILES Type: ZSTZ 630 C3 Max. gear diameter = 630 mm Tooth width = 215 mm Module = 1 – 12 Number of teeth = 5 – 140 Table diameter = 500 mm Stroke = 500 mm Grinding wheel diameter = 270 – 350 mm Swivel range = 45° Rodpfjwl Aunjx Ab Tocf Strokes = 75 – 315 per minute Weight approx. = 6.3 t

Condition: good (used), Year of construction: 1999, 8-spindle grinding system Electrical connection power: 17 kW/380 V/50 Hz Rjdpfx Ajw Sdhnsb Tocf

Condition: excellent (used), Year of construction: 2021, functionality: fully functional, machine/vehicle number: 2145027, grinding length: 800 mm, grinding width: 400 mm, workpiece weight (max.): 400 kg, grinding wheel diameter: 405 mm, distance table to spindle center: 550 mm, table length: 800 mm, table load: 400 kg, type of input current: AC, table width: 400 mm, overall weight: 3,250 kg, grinding spindle motor power: 6,800 W, input voltage: 380 V, space requirement height: 1,900 mm, space requirement length: 3,450 mm, space requirement width: 2,050 mm, NC Auto down feed system and Parallel dresser Handwheel Redozxdh Tepfx Ab Tscf Dimension of table (magnetic plate): 800 x 400 mm Distance: table - spindle head: 550 mm Table speed: 5-25 m/min Dimension of grinding wheel: fi 405 x 50 x 127 mm Motor power: 5HP Hydraulic pump motor: 2 HP Equipped with Easson SC-402 2-axis digital readout (DRO) for precise positioning Paper filter and magnetic separator Condition: Overall in very good condition

Year of construction: 2018, condition: used, overall weight: 10,000 kg, total length: 2,300 mm, total width: 6,500 mm, total height: 2,400 mm, BUDERUS CNC 235 – CNC Grinding and Machining Center Machining / Spindle 2 machining areas / channels Max. machining length: 150 mm Max. swing diameter: Ø 310 mm Workpiece spindle speed: 0–3,000 rpm Spindle bore: Ø 45 mm Workpiece spindle positioning via C-axis Table speed X/Z: 0–30 m/min Motor Spindle WMZ / DVS Type: GS 205-045/17 Year of manufacture: 2014 Automation Rcedpszwa Rhsfx Ab Tjf Automatic workpiece feed / conveyor system Coolant / Filtration System LIQUI-Filter GmbH System: UR1060 / MW260 / Gamma 13 Tank capacity: 2,400 l Year of manufacture: 2015 Cooling System HYFRA gamma 13-F-S Cooling capacity: 13 kW at 32 °C Year of manufacture: 2015 Measuring Technology JENOPTIK post-process measuring technology Year of manufacture: 2018 Supply Data 3 × 400 V / 50 Hz Installed power: approx. 45 kW Compressed air requirement: 15 Nm³/h at 5 bar Control: Siemens SINUMERIK 840D Travel Z-axis: 300 - mm Workpiece diameter over bed max.: 150 mm Weight approx.: 10,000 kg Dimensions (LxWxH) approx.: 2300 x 6500 x 2400 mm Travel X-axis: 1240 - mm Year of construction: 2,018 Condition: good Terms of payment: 100% prepayment before pick-up Terms of delivery: Free loading on truck under power: No

Condition: used, Year of construction: 2013, max. wheel diameter 260 mm gear width 320 mm max. module 4,5 min. module 0,5 Control SIN 840D max.helical angle +/- 45 ° total power requirement 68 kW weight of the machine ca. 15,50 t dimensions of the machine ca. 3,25 x 3,25 x 3,30 m Fire extinguishing system Siemens Sinorix TM Knoll Filtering system VL1500/8000 year 2017 Redpox R U Hgofx Ab Tscf Wekal loading cell

Condition: used, Year of construction: 2012, max. wheel diameter 300 mm gear width 320 mm max. module 10 min. module 0,5 control Siemens SIN840D max.helical angle 45 ° frequency 50 Hz voltage 400 V main fuse 125 A x-axis 270 mm y-axis 250 mm z-axis 320 mm A - axis +/- 45 ° B - axis 360 ° C-axis 360 ° total power requirement 89 kW weight of the machine ca. 23,5 t dimensions of the machine ca. 11,2 x 5,5 x 2,9 m automated Oil slinger station EWAB workpiece storage Hoffmann coolant filter system HSF 100 SE/K Minimax fire extinguishing system Rcodpfxsx R U Hao Ab Tjf W+W air filter system Promot Automation "Cellmaster" (3 cells) year 2019

Condition: used, Year of construction: 2006, ratio of transmission 10:1 min. number of teeth 3 max. number of teeth 200 range of tooth size 20 mm tooth width max. 58 mm spindle speeds (infinitely variable) 6000 U/min work piece spindle speed 1200 U/min diameter of tools max. 230 mm diameter of tools min 69,85 mm x-axis 325 mm y-axis 350 mm z-axis 470 mm b-axis + 90,1 / - 1 ° work piece table - Ø 212,71 mm Control SIN 840 D SIEMENS total power requirement 75 kW weight of the machine ca. 10,00 to dimensions of the machine ca. 6,10 x 4,40 x 3,30 m coolant filtering unit Hoffmann HSF 100 V Rcjdpjvxwr Asfx Ab Tjf

Condition: refurbished (used), Year of construction: 2020, Machine Type: Cylindrical Grinding Machine Manufacturer: Schaudt Maschinenbau GmbH Model: PS 4 Year of Original Manufacture: 1986 Renovation/Retrofit: 2020 Control System (Post-Retrofit): Siemens CNC SINUMERIK 840D General Specifications Application: External cylindrical grinding Grinding Method: Plunge, traverse, face grinding Control Type: CNC (Siemens retrofit in 2020) Machine Weight: Approx. 3,500 – 4,500 kg Installation Area: Approx. 3.5 m x 2.0 m Workpiece Capacity Center Height: 180 mm Distance Between Centers: 1000 mm (varies by version) Max Workpiece Diameter: 360 mm Max Workpiece Weight: ~150 kg between centers Grinding Spindle Grinding Wheel Diameter: 400 mm Grinding Wheel Width: 50 mm Bore: 127 mm Peripheral Speed: Up to 45 m/s Spindle Drive Power: ~7.5 kW Spindle Speed Range: Up to 1,500 – 2,500 rpm (depending on wheel size) Headstock Type: Fixed or rotating spindle Speed Range (if motorized): ~30 – 500 rpm Taper: MK4 or similar Drive: AC Servo (post-retrofit) Tailstock Type: Manual or hydraulically actuated Quill Stroke: Approx. 50 mm Quill Diameter: ~75 mm Axes X-Axis (infeed): CNC-controlled Z-Axis (longitudinal): CNC-controlled Resolution: 0.001 mm Drive Type: Digital servo motors with ball screw Position Feedback: Absolute/Incremental linear encoders Coolant System Coolant Tank Capacity: Approx. 150 – 250 liters Coolant Pump: High-pressure, with filtration system Other Features (Post-Retrofit) Siemens HMI with touch interface Electronic handwheels (MPG) Updated safety system and enclosure New electrical cabinet with ventilation and cooling Rsdpfxsw Avrzj Ab Tjcf Optional AE sensor for gap detection or touch dressing

Condition: used, Year of construction: 1950, width of the strips 150 mm band length 6680 mm volt 380 V weight 800 kg Rodpfx Abjua Ivcj Tocf dimensions of the machine ca. 3,2x1,6x1,75 m Wood surface sanding machine Carriage length: table size 2500 x 800 mm Belt length: 150 x 6680 mm Manual processing table, adjustable Table height adjustable

Condition: used, Year of construction: 2008, functionality: fully functional, machine/vehicle number: 146978, Knuth Surface Grinding Machine Flat HFS 2500C Working Area & Capacities Table dimensions: 250 x 500 mm Grinding area (max.): approx. 500 x 250 mm Maximum workpiece weight: 180 kg Distance spindle center to table surface: 450 mm Travel Distances & Feeds Longitudinal travel (X-axis): 560 mm Cross travel (Y-axis): 275 mm Hydraulic table feed (X): 7 – 23 m/min Rapid traverse cross (Y): 990 mm/min Rapid traverse vertical (Z): 460 mm/min Spindle & Grinding Wheel Grinding spindle motor power: 2.2 kW Grinding wheel dimensions: 200 x 20 x 31.75 mm Graduation: Y-axis 0.02 mm / Z-axis 0.005 mm Dimensions & Weight Machine dimensions (LxWxH): approx. 2650 x 2150 x 1675 mm Rodpfx Asy H Dg Ijb Tecf Total weight: approx. 1800 kg

Condition: excellent (used), Year of construction: 1965, functionality: fully functional, spindle speed (min.): 10,000 rpm, spindle speed (max.): 60,000 rpm, Equipment: rotational speed infinitely variable, Overbeck overhauled in 2015 and equipped with fast frequency spindle SC3060-V1000, frequency converter SD2T 3.8kVA and cooling unit PHK525 HZ, cooling capacity 550W Rcjdpfju Aqt Ejx Ab Tjf

Year of construction: 2008, condition: ready for operation (used), functionality: fully functional, MONTANA DIAMOND Crystal Glide Ski Servicing Robot – in excellent condition and ready for immediate use! For sale is a high-performance, fully automatic machine for professional winter sports servicing. This machine is specifically designed for workshops with high service volumes and, thanks to its 2 grinding stones, delivers first-class, fully automatic results. What makes this machine special: it has been meticulously maintained, cared for, and serviced by the owner himself throughout the years. It has been completely overhauled – many important core components, including the motors, have been recently replaced. Ready for immediate use – no backlog of maintenance required. The machine can be put into operation directly in your workshop. Rcedpfezv Sqdex Ab Tsf The price includes 2 grinding stones, diamonds, and sensors (value of approximately €3,400). Please refer to the attached documentation for detailed technical information and specifications. Viewing is possible until the end of September. Pick-up only / transport must be arranged by the buyer. Sale to businesses, excluding any warranty. For sales to foreign countries: VAT invoice IGL (Intra-Community Supply).

Condition: used, center height: 100 mm, grinding length: 500 mm, Cylindrical grinding machine FORTUNA R 500 for sale. The machine was last operated in 2017 and has been stored in a warehouse since then. Therefore, it is being sold as defective – without warranty. Loading is possible. Rcjdpfx Abjxx T Ezs Tsf

Condition: repair required (used), For sale is a robust BLOHM SIMPLEX surface grinding machine in a heavy-duty industrial design. Technical data / equipment: * Manufacturer: BLOHM * Type: SIMPLEX * Travel in X-axis: approx. 600 mm * Travel in Y-axis: approx. 300 mm Rcjdszwv A Tjpfx Ab Tof * Magnetic chuck * Coolant system * Automatic table feed * Manual feed * Heavy-duty and robust machine construction Known defect: The automatic feed is currently not functioning. However, the feed can be performed manually. Apart from this, the machine is in technically sound and operational condition. The machine is particularly suitable for surface grinding, repair work, individual parts, and general tool, mold, and machine construction. Used, condition commensurate with age. Inspection and demonstration possible by appointment. The stated selling price is the net price plus the statutory value-added tax. Sale is made commercially with an invoice.

Condition: good (used), Year of construction: 2014, functionality: fully functional, Table surface: 850 x 400 mm Magnetic table: 800 x 400 x 105 mm Max. table travel (X x Y): 950 x 440 mm Max. workpiece weight: 700 kg (230 kg on the magnetic table) T-slots on the table: 3 pcs x 17 mm Distance between table and spindle center: 47,5 – 547,5 mm Rcjdpfx Asy T Nuwob Tjf Grinding wheel dimensions: D355 x 38 x d127 mm Spindle speed: 1500 / 1800 rpm (50Hz / 60Hz) Spindle drive power: 3.7 kW / 4.0 kW Longitudinal travel: 3 – 25 m/min (hydraulic and stepless) Cross travel: 1 – 1000 mm/min Vertical feed rate: 1 – 1000 mm/min Minimum increment / feed amount: 0,0001 mm – 0,0002 mm Machine weight: 4000 kg Dimensions (L x W x H): 3310 x 2228 x 2710 mm Accessories / Equipment - Semi-automatic operation - Magnetic table 800 x 400 mm - Coolant system with magnetic separator - Paper band filter - Machine feet - Digital display system for the infeed / increment - Built-in wheel dresser in the spindle head The machine is being sold due to company liquidation. It is in good condition and still under power in Hungary.

Condition: used, Year of construction: 2008, functionality: fully functional, input frequency: 50 Hz, type of input current: AC, input voltage: 400 V, pressure: 6 bar, 8-disc glass grinding and polishing machine. In excellent working condition! 8 discs Glass thickness 3 - 35 mm Min. glass size 40X40 mm Speed ​​0.5 - 5m/min. Power: 19.5kW Power supply: 400V Rcsdpfezn Nriex Ab Tjf The machine is in excellent technical condition, can be viewed, tested, and purchased at a pre-arranged time.

Condition: new, neu ca. 6 Monate ab Auftragse Taiwan Rodpfx Aszwqa Hsb Tscf 83670 € 1581.36 € 810 mm 610 mm 800 x 400 mm 800 x 400 mm 5 - 25 m/min 0 - 2.250 mm/min 450 mm 0 - 675 mm/min 480 mm 500 - 2200 1/min 3,75 (optional 5,5 / 7,5) kW 1.5 kW 3250 mm 3075 mm 2250 mm 2900 kg 175 kg 350 kg 355 x 50 x 127 mm 1,1 kW Fully enclosed splash guard 10.4" graphic NC control on a swivel arm with touchscreen for: Operating mode selection Cycle selection and program creation Surface grinding Cross grinding Plunge grinding Dressing with automatic compensation Semi-automatic balancing in the machine Automatic spindle speed for constant surface speed Spindle load visualization Unbalance control Graphical status monitoring Alarm list automatic vertical feed servo drive for grinding wheel feed and table cross feed heavy duty spindle with 2 sets (4) of class P4 super precision angular contact ball bearings hardened and ground C2 grade ballscrew on crossfeed and elevation hardened slide ways electro-magnetic chuck coolant equiptment with aut. paper filter and magnetic separator autom. dressing attachment table mounted with compensation grinding wheel grinding wheel flange grinding wheel balancing stand LED machine lamp machine and equipment according to the CE-regulations user manual in GERMAN and ENGLISH OPTIONS (PRICES ON REQUEST): autom. dressing attachment mounted over the wheel version without fully enclosed splash guard

Condition: new, DAWN DN Series (Single Spindle) Rcjdpfx Ajubbp Sjb Tjf Dawn Machinery Machine overview Suitable for grinding inside and outside diameters as well as the end surface of heavy or non circular work pieces. Heavier work pieces can be more easily loaded to the machine by overhead hoist Fully enclosed covers and oil mist reclaiming device prevent leakage of grinding oil and mist. Machine options Model DN-500 Specification Model DN-500 Grinding Diameter (Max) 610mm ø Swing (Max) 610mm ø Max work height 400mm Motor Power 18/23kW CNC Control System SIEMENS 828D

Condition: new, functionality: fully functional, Jainnher Machine Co., Ltd. was established in 1982 and is dedicated to developing grinding machine technology, diversity and automation equipment. Jainnher is constantly offering new and improved machinery. The new JAINNHER JHP-4015 CNC Plunge Type machine with FANUC CNC Control. Hydrostatic and Hydrodynamic bearings. Capacity Max ø work swing Ø400 mm Max grinding length 1500mm Max grinding dia. Ø380 mm Max workpiece weight 150 kgs Distance between centres 1500mm Centre height 200mm Grinding wheel Grinding wheel size Ø410 x 50-100 x 203.2mm Max peripheral 33 m/sec Wheel speed 1250rpm Wheel head Feed angle 90 Swivel angle ±0 Rapid traverse speed 6m/min Max. travel 280mm Min. setting unit 0.0001mm Grinding feed rate 0.001~6000m/min Oil Pressure Hydrostatic = 20kg Hydrodynamic = 3kg Tailstock Retraction of quill 30mm Quill diameter 70mm Centre taper MT.4 ( MT.5 option) Hydraulic cylinder pressure 20kg Work head Spindle speed (variable) 10~500rpm/min Rodpenzib Ejfx Ab Tjcf Centre taper MT.4 ( MT.5 option) Spindle type Telescopic (option Swivel angle 120 (90ºCCW;30ºCW) Work- table Min. setting unit 0.0001mm Swivel angle CCW/CW +7º/-4º Rapid traverse speed 10m/min Max. travel 1500mm Motor Grinding feed rate 0.001~6000mm/min Grinding wheel motor 7.5HP 4P(opt. 10.0HP) 4P Workhead motor 1.5KW Work table (Z axis) 1.8KW Work table (X axis) 1.8KW Hydraulic pump 1/4 HP 4P Wheel head pump Hydrostatic = 2.0HP Hydrodynamic = 1.0HP Coolant pump 1/8 HP 2P Magnetic coolant separator 1/25HP 2P Oil cooler ----- Oil tank Hyd. oil tank(slideways, screw ends & measurement) 60L Wheel head lubrication 50L Coolant tank 160L Machine N.W (Fully enclosed) 8080 kg G.W (Fully enclosed) 8480 kg Dimension (Fully enclosed) 4900 x 2100 x 2000mm Packing (Fully enclosed) 5090 x 2200 x 2200mm

Condition: excellent (used), functionality: fully functional, machine/vehicle number: 1761-1700, 457 x 152mm capacity. Equipped with magnetic chuck, power rise and fall to wheel head, table guard, coolant system, and dust extraction. SPECIFICATION Jones & Shipman Model 540P Working Surface of table 457 x 152mm Longitudinal traverse of table, hand and hydraulic 483mm Total cross traverse of table, hand and hydraulic 168mm Floor to table height 1035mm Table traverse speed range per min 1.5 – 18m Cross feed range per stroke at each reversal 0.178 – 1.78mm Micrometer cross feed graduated in Vertical feed adjustment in increments of 0.002mm Vertical movement of wheelhead (max) 280mm Wheel spindle center to table (min) 50mm Size of grinding wheel 180 x 13 x 31.75mm bore Speed of wheel 2880rpm Wheelhead motor 1.5kW Hydraulic pump motor 0.55kW Machine in Imperial execution MACHINE EQUIPPED WITH Rcjdpfx Abenxi Uus Tef Magnetic chuck Power rise and fall to wheel head Table guard Wheel guard Coolant System Dust extraction

Condition: new, Year of construction: 2025, functionality: fully functional, With a grinding diameter of 200mm x 300mm long, the JHP-2003CNC is the most compact plunge type grinding machine in the range and utilises the FANUC Oi-TF CNC control. Designed for heavier grinding applications, the JHP-2003CNC can accomadate workholding and components to 80kgs. This fully enclosed machine is supplied with Renishaw probing, full machine enclosure and mist collector. Jainnher CNC Plunge Cylindrical Grinding Machine Description: JHP-2003 CNC Capacity Max ø work swing 200mm dia Max grinding length 300mm Max grinding dia. 200mm dia Max workpiece weight 80 kgs Distance between centres 300mm Centre height 100mm Grinding wheel Grinding wheel size Ø405 x 50 x 127 Max peripheral 33 m/sec Wheel speed 1780rpm Wheel head Feed angle 90 Swivel angle ±0 Rapid traverse speed 6m/min Max. travel 220mm Min. setting unit 0.0001mm Grinding feed rate 0.001~6000m/min Hydrodynamic pressure ----- Tailstock Retraction of sleeve 30mm Sleeve diameter D:48mm Centre taper MT.3 Hydraulic cylinder pressure 20kg Work head Spindle speed (variable) 10~500rpm/min Centre taper MT3 Spindle type Cartridge type Swivel angle 120 (90ºCCW;30ºCW) Work- table Min. setting unit 0.0001mm Swivel angle CCW/CW +10º/-3º Rapid traverse speed 8mm/min Rcjdponxk N Ssfx Ab Tef Max. travel 640mm Motor Grinding feed rate 0.001~6000mm/min Grinding wheel motor 5HP 4P(opt. 7.5HP) 4P Workhead motor 1.0KW Work table (Z axis) 1.2KW Work table (X axis) 1.2KW Hydraulic pump 1/4 HP 4P Wheel head pump ----- Coolant pump 1/8 HP 2P Magnetic coolant separator 1/25HP 2P Oil cooler ----- Oil tank Hyd. oil tank(slideways, screw ends & measurement) 30L Wheel head lubrication ----- Coolant tank 80L Machine N.W (Fully enclosed) 3800 kg G.W (Fully enclosed) 4100 kg Dimension (Fully enclosed) 3300 x 2100 x 2200mm Packing (Fully enclosed) 3500 x 2200 x 2200mm Jainnher CNC Plunge Cylindrical Grinding Machine Standard Accessories: JAINNHER JHP-2003CNC X-axis linear scale Work lamp Foot pedal Angle adjustment gauge Hydraulic tailstock with manual movement Grinding wheel and flange Tungsten carbide tipped centres (MT3) Automatic lubrication system Diamond dresser at lower worktable Magnetic separator MC-40/coolant tank/pump Levelling bolts and blocks Tool kits and toolbox Fully enclosed splash guard & oil mist device Touch probe gauge (Renishaw) Transformer

Condition: excellent (used), Year of construction: 1984, functionality: fully functional, machine/vehicle number: BO 94392, A familair machine in any toolroom, this Jones and Shipman 540P is equipped with a 6″ x 18″ magnetic chuck, power rise and fall, coolant system and dust extraction. A toolroom institution: USED Jones & Shipman Model 540P Horizontal Spindle Surface Grinding Machine Specification Working Surface of the table 457 x 152mm Longitudinal traverse of table, hand and hydraulic 483mm Total cross traverse of table, hand and hydraulic 168mm Floor-to-table height 1035mm Table traverse speed range per min 1.5 – 18m Cross-feed range per stroke at each reversal 0.178 – 1.78mm Micrometer cross feed graduated in Vertical feed adjustment in increments of 0.002mm Vertical movement of wheelhead (max) 280mm Wheel spindle centre to table (min) 50mm Size of grinding wheel 180 x 13 x 31.75mm bore Speed of wheel 3000rpm Wheelhead motor 1.5kW Hydraulic pump motor 0.55kW Machine in Imperial execution Machine equipped with Magnetic chuck Power rise and fall to wheel head Table guard Wheel guard Coolant System Rsdonxi R Uspfx Ab Tscf Dust extraction Lighting

Condition: new, functionality: fully functional, he EUROPA JAINNHER JHV-1008CNC vertical grinding machine is designed for grinding of large components used in the transport, aerospace, power generation, oil & gas, hydraulic and precision components. With a grinding internal diameter range from Ø50 to 800 mm, a maximum outside diameter of Ø1000 mm. The maximum height of the workpiece is 800mm, with a maximum worktable load of 1200 kg. EUROPA Jainnher JHV-1008 CNC Vertical Grinder Capacity Range of I.D. grinding 50 – 800mm Maximum O.D grinding 1000mm Z axis maximum grinding height (OD) 800mm Redpfjnzkvhex Ab Tscf Z axis maximum grinding height (ID) 50 – 250 : 325mm / 250 – 800 : 800mm Maximum swing diameter 1000mm Maximum installed component height 800mm Maximum work table load 1200kg Email for latest factory build availability