Homag Rezkanje Motor Za Rob Obdelovalnih Strojih nakup rabljenega (95.210)

Stanje: dober (rabljeno), Aggregate construction kit, formatting unit, cutting unit, milling unit, profile milling unit, jointing milling unit, cross-cutting unit, double-end profiler, edge processing machine, scoring motor, cutting motor, milling motor for edge processing machine - HOMAG cross-cutting unit for trimming edge overhangs at the front and rear edges - with heavy-duty guide Lodob Sgzaspfx Ah Usrl - Milling unit: swiveling - 1x Perske motors - Motor type: - Power: 0.75 kW - Voltage: Volt - Frequency: 300 Hz - Speed: 8,600 rpm - Other motors with different power ratings available from stock at extra charge - Dimensions: 940/620/H350 mm - Weight: 54 kg

Stanje: dober (rabljeno), Modular aggregate system, format processing aggregate, machining (cutting/removal) aggregate, milling aggregate, form milling aggregate, jointing milling aggregate, cross-cutting aggregate, double-end profiler, edge processing machine, scoring motor, machining motor, milling motor for edge processing machine -HOMAG milling aggregate for: jointing milling -with: heavy-duty dovetail guide -Milling aggregate: swiveling -3x Perske motors -Motor 1: Type KCS 70.12-2 D -Power: 3/4.4 kW -Voltage: 220/380/380 Volt Lodpfxjdx Aiwe Ah Usrl -Frequency: 50/100 Hz -Speed: 2880/5880 rpm -Motor 2: Type KCS 70.12-2 D -Power: 3/4.4 kW -Voltage: 220/380/380 Volt -Frequency: 50/100 Hz -Speed: 2880/5880 rpm -Motor 3: Type KNS 51.14-2 D -Power: 1/2 kW -Voltage: 220/380/380 Volt -Frequency: 50/100 Hz -Speed: 2750/5700 rpm -Other motors with different power ratings available from our stock at an additional cost -Quantity: 1x jointing milling aggregate available -Price: per unit -Dimensions: 1370/1100/H1330 mm -Weight: 608 kg

Stanje: dober (rabljeno), Modular aggregate construction kit, format processing unit, cutting unit, milling unit, profile milling unit, joint milling unit, cross-cutting unit, double-end profiler, edge processing machine, scoring motor, cutting motor, milling motor for edge processing machine -Manufacturer: Homag, milling unit for edge processing machines with Perske motor -Milling units: swiveling -Motor: Perske DVMS 903/2 -Power: 0.40 kW -Frequency: 200 Hz Lrjdpfovxghgjx Ah Uel -Speed: 12,000 rpm -Dimensions: 440/380/H595 mm -Weight: 56 kg

Stanje: dober (rabljeno), Aggregate modular system, contour processing unit, cutting unit, milling unit, form milling unit, joint milling unit, crosscutting unit, double-end profiler, edge processing machine, scoring motor, cutting motor, milling motor for edge processing machine Lrodpfob Sab Hsx Ah Uel -HOMAG crosscutting unit for trimming edge overhangs at the front and rear edges -with heavy-duty guide -Milling unit: tiltable -2x Perske motors -Motor type: -Power: 0.22 kW -Voltage: Volt -Frequency: Hz -Speed: 18,000 rpm -Other motors with different power ratings available in stock at extra cost -Dimensions: 1240/600/H1100 mm -Weight: 296 kg

Stanje: rabljeno, modular aggregate system, format processing unit, machining unit, milling unit, contour milling unit, edge jointing unit, cross-cutting unit, double-end profiler, edge processing machine, scoring motor, machining motor, milling motor for edge processing machine -HOMAG milling unit for joint milling -with heavy-duty dovetail guide -milling unit: swiveling -2x Perske motors -Motor 1 Type: KNS 71.16/201 -Power: 4.4/6.6 kW -Voltage: 220/380/380 Volt -Frequency: 50/100 Hz -Speed: 2860/5870 rpm -Motor 2 Type: MP-10-L -Power: 1.0/1.5 kW -Voltage: 220/380/380 Volt -Frequency: 50/100 Hz -Speed: 3000/6000 rpm Ledpfx Ahob Uhi No Usrl -other motors with different power ratings available in stock at extra cost -Quantity: 1x joint milling unit available -Price: per piece -Dimensions: 900/1000/H1030 mm -Weight: 360 kg

Stanje: dober (rabljeno), Aggregate construction kit, format processing unit, machining unit, milling unit, contour milling unit, jointing milling unit, cross-cutting unit, double-end profiler, edge processing machine, scoring motor, machining motor, milling motor for edge processing machine -HOMAG milling unit for joint machining -with heavy-duty dovetail guide -Milling unit: swiveling -1x Perske motor -Motor type: KCS 70.12-2D -Power: 2.7/4.5 kW Lsdpjb R Ua Njfx Ah Ujrl -Voltage: 220/380/380 Volt -Frequency: 50/100 Hz -Speed: 2,860/5,860 rpm -Other motors with different power ratings available from stock at extra cost -Dimensions: 1060/660/H1010 mm -Weight: 326 kg

Stanje: dober (rabljeno), Aggregate kit, profile machining unit, cutting unit, milling unit, contour milling unit, joining milling unit, cross-cutting unit, double-end profiler, edge processing machine, scoring motor, cutting motor, milling motor for edge processing machine - Manufacturer: Homag, milling unit for edge processing machines with Perske motor - Milling units: swiveling - Motor: Perske DKNS 502/2 Ledpovyz D Ssfx Ah Usrl - Power: 0.15 kW - Frequency: 200 Hz - Speed: 10,400 rpm - Dimensions: 480/360/H595 mm - Weight: 60 kg

Stanje: dober (rabljeno), Aggregate module, format processing unit, cutting unit, milling unit, profile milling unit, jointing milling unit, cross-cutting unit, double-end profiler, edge processing machine, scoring motor, cutting motor, milling motor for edge processing machine Ledpfx Aovy Ah Esh Ujrl -Manufacturer: Homag, milling unit for edge processing machines with Perske motor -Milling unit: with guide -Motor: Perske VS 31.09-2 -Power: 0.4 kW -Frequency: 200 Hz -Speed: 11,300 rpm -Quantity: 2x milling units available -Price: per piece -Dimensions: 600/360/H310 mm -Weight: 20 kg/unit

Stanje: pripravljen za uporabo (rabljen), Leto izdelave: 2004, obratovalne ure: 23.291 h, Funkcionalnost: popolnoma funkcionalen, potovalna razdalja osi X: 3.200 mm, pomik osi Y: 1.400 mm, pomik po osi Z: 750 mm, dolžina mize: 3.200 mm, širina mize: 1.400 mm, TEHNIČNI PODATKI Pomik X-os: 3.200 mm Pomik Y-os: 1.400 mm Pomik Z-os: 750 mm Velikost mize: 3.200 x 1.400 mm PODROBNOSTI STROJA Vrsta krmiljenja: CNC Lredey R Dn Hepfx Ah Usl Krmilni sistem: Heidenhain Obratovalne ure Obratovalni čas vretena: 23.291 h Delovni čas programa: 27.807 h Čas vklopa krmiljenja: 83.301 h Čas vklopa stroja: 73.907 h

Stanje: rabljeno, Stanje polovno Broj skladišta 3985 Rok isporuke odmah, međuprodaja moguća Zemlja porekla Švedska Cena 1800 € Na stanju 1 Kapacitet bušenja u konstrukcionom čeliku 25 mm Prihvat MK 3 Radijus 235 mm Brzine vretena 100 - 2080 (8) o/min Dužina 750 mm Širina 900 mm Visina 1550 mm Težina 250 kg Lsdpfoynmyxox Ah Uerl Podizanje vretena ručnim točkom Bušaća glava podešavajuća po visini i nagibu Križni sto sa ručnim pomeranjem po X i Y osi Ne odgovara nemačkom UVV i austrijskoj AMVO Bez uputstva za upotrebu KUPOVINA POLOVNIH MAŠINA JE PITANJE POVERENJA – NAŠ OBEĆANJE TRANSPARENTNOSTI Nudimo Vam maksimalnu sigurnost i potpunu transparentnost. • ISKRENI UVID Detaljne fotografije & video-snimci funkcionalnog stanja • PROVERA UŽIVO Testiranje kod nas u firmi • DIGITALNA DEMONSTRACIJA Individualna prezentacija uživo putem video poziva • KUPOVINA BEZ RIZIKA Pravo na povraćaj u roku od 14 dana Detalji:

Stanje: rabljeno, Leto izdelave: 2023, Condition: Used Year of manufacture: 2023 Stock number: 4546 Delivery: Prompt, subject to prior sale Country of origin: Taiwan Price: €32,800 In stock: 1 Spindle speeds: 65 - 2600 rpm Spindle taper: ISO 40 Working range: 420 x 220 x 380 mm Table size: 840 x 390 mm Motor: 2.2 kW Length: 1600 mm Width: 1700 mm Height: 2000 mm Weight: 1,145 kg Clamping surface: 840 x 390 mm Rapid traverse/feed in all 3 axes: 1,000 mm/min T-slots: 5 Width x spacing: 14 x 63 mm Max. table load: 200 kg Longitudinal travel: 420 mm Cross travel: 220 mm Vertical travel: 380 mm Infinitely variable feed X/Y: 0 - 600 mm/min Infinitely variable feed Z: 0 - 600 mm/min Horizontal spindle speed ranges: 65 - 2600 Spindle axis distance from column guide: 90 - 310 mm Vertical spindle speed ranges: 65 - 2600 Spindle swiveling range: +/- 90° Quill stroke: 100 mm Manual tool clamping Spindle motor: 2.2 kW Vertical table: 950 x 250 mm Distance vertical milling spindle - table: 90 - 310 mm Distance horizontal milling spindle - table: 100 - 480 mm Demo machine / like-new condition Net price (original price €41,100.00) Equipped with: • Swiveling control panel • 3-axis digital readout Fagor 40i Innova • Motors for horizontal and vertical spindle: 2.2 kW • Inverter feed motors for X/Y/Z: 0.35 / 0.35 / 0.75 kW • Ball screws for X/Y/Z-axes • Gearbox for spindle speeds • 1 pc. long milling arbor 27 mm • 3 reducing sleeves (MK1, MK2, MK3) • 1 drawbar ISO 40 for horizontal or vertical spindle • Spindle guard with safety switch • Safety enclosure in working area with electrically interlocked doors • Counterholder for horizontal milling Lrsdpewirdgofx Ah Uol • LED work light • Automatic lubrication for X/Y/Z guides • Safety handwheels for X/Y/Z axes • Coolant unit with chip tray • Covers for X/Z axes • Base plates and bolts • Toolbox with operating tools • Operating manual in German or English • CE conform equipment USED MACHINERY PURCHASE IS A MATTER OF TRUST – OUR TRANSPARENCY PROMISE We offer you maximum security and full transparency. • HONEST INSIGHTS Detailed photos & function videos of the actual condition • ON-SITE LIVE CHECK Live demonstration at our facility • DIGITAL DEMO Individual live video presentation • RISK-FREE PURCHASE 14-day return policy Details:

Stanje: rabljeno, Special pantograph for milling baby cot legs. Lsdpfx Aey S Acljh Uorl Head movement controlled by foot pedal; workpiece movement pneumatic.

Leto izdelave: 2007, stanje: zelo dobro (rabljeno), Funkcionalnost: popolnoma funkcionalen, Skladišče za nalaganje palic Največja dolžina nalagajočih palic: 7500 mm Enota za pozicioniranje palice Lsdpsy Tqabefx Ah Ujrl Hitrost vozička: 0÷60 m/min Rezkalna enota: 4 elektromotorna vretena po 4,5 kW vsak Stožec držala orodja: ISO 25 Hod osi X: 240 mm Hod osi Y: 350 mm Hod osi Z: 350 mm Rezalna enota s pnevmatskim pozicioniranjem Premer lista: 550 mm Rezalni koti: 45° – 90° – 135° Avtomatski izpust

Leto izdelave: 2008, stanje: zelo dobro (rabljeno), Funkcionalnost: popolnoma funkcionalen, - Skladišče za nalaganje palic Največja dolžina nalagajočih palic: 7500 mm - Enota za pozicioniranje palice Hitrost prevoza vozička: 0÷60 m/min - Rezkalna enota: 4 elektromandrelji po 4,5 kW vsak Konična pritrditev orodja: ISO 25 Hod osi X: 240 mm Hod osi Y: 350 mm Hod osi Z: 350 mm - Rezalna enota s pnevmatskim pozicioniranjem Premer žage: 550 mm Rezalni koti: 45° - 90° - 135° Lodey S E H Hopfx Ah Uerl - Avtomatski izmet

Stanje: rabljeno, Leto izdelave: 2011, proizvajalec krmilnikov: Siemens, model krmilnika: C200-4D SL, Description: General: Year of manufacture: 2011 Control: Siemens 840 Dsl (C200-4D SL) Bar capacity: 65 mm Milling spindles: 18,000 rpm Main spindle: Technology: Motor spindle Speed: 5,000 rpm Max. power: 35.5 kW Max. torque: 170 Nm C-axis: 0.001° Z-axis: 390 mm Bar capacity: 65 mm Chuck cylinder: Hollow clamping cylinder Chuck: 3-jaw chuck Counter spindle: Technology: Motor spindle Lredpfxsy Sq T Se Ah Usl Speed: 5,000 rpm Max. power: 35.5 kW Max. torque: 170 Nm C-axis: 0.001° X-axis: 600 mm Z-axis: 390 mm Bar capacity: 65 mm Chuck: 3-jaw chuck Tool carrier I: Technology: Milling spindle on cross slide Speed: 18,000 rpm Tool holder: HSK 40 X-axis: 350 mm Y-axis: 160 mm (+/- 80 mm) B-axis: 230° Tool carrier II: Technology: Milling spindle on cross slide Speed: 18,000 rpm Tool holder: HSK 40 Y-axis: 160 mm (+/- 80 mm) B-axis: 230° Tool magazine: Technology: Chain magazine Number of stations: 80 pcs Tool changer: Double gripper Max. tool length: 180 mm Equipment / Accessories: Chip disposal: Chip conveyor Coolant supply: High-pressure coolant system with filter Workpiece removal: Gantry loader

Stanje: rabljeno, Leto izdelave: 2014, obratovalne ure: 33.100 h, številka stroja/vozila: 2941, Krmiljenje HEIDENHAIN TNC530, hodi X/Y/Z: 3.500x1.200x1.250 mm, nihajna glava: 2,5°, vpenjalo orodja: SK50, 60 orodnih mest, transporter ostružkov URRETXU 11-20132, serijska št.: 4855492004U5E2, filtrirni sistem JUMA+GAIN, serijska št.: 7136, zmogljivost: 60 l/min, letnik: 2013 Lodpoy T Nx Njfx Ah Ujrl

Leto izdelave: 2016, obratovalne ure: 17.607 h, stanje: rabljeno, številka stroja/vozila: 7975, Krmiljenje HEIDENHAIN TNC640, pomik X/Y/Z: 10.000x1.300x2.200 mm, nagibna glava: 2,5°, držalo orodja SK50, 60 mest za orodja, transporter ostružkov AXA FSB 300/TLG.63, serijska št.: 173492-2, letnik: 2016, filtrirni sistem JUMA+GAIN, serijska št.: 8276, kapaciteta: 100 l/min, letnik: 2016, vključno z 2 stojali 90°. Lredpfx Aoy T Nyajh Ujl

Stanje: rabljeno, Leto izdelave: 1996, Dolžina obdelovanca: 55–170 mm Lrodpfxsy Ty Hqo Ah Usl Največja širina obdelovanca: 28 mm Največja višina obdelovanca: 27,5 mm Število rezkalnih agregatov: 2 Prečna žaga: 1 Posebni stroj: avtomat za žaganje in rezkanje APK za odrezovanje na dolžino in naknadno rezkanje lesenih blokov. Posebna izvedba za izdelavo vložkov vstavkov za predale s priborom (glej slike) ali podobnih obdelovancev. Delovni potek: 1. Dovod materiala iz zalogovnika 2. Odrez (žaganje) na želeno dolžino 3. Rezkanje odrezanih obdelovancev 4. Izmet končnega kosa.

Stanje: novo, Condition: New Delivery time: approx. 12 – 14 weeks from order Country of origin: Spain Price: €50,410 Leasing rate: €952.75 Drilling capacity in structural steel: 35 mm Spindle taper: MT 4 Throat: 390 mm Speeds: 94–2,225 RPM (16 steps) 50 Hz, 113 RPM Thread cutting capacity: M35 Length: 1,660 mm Width: 1,510 mm Height: 2,600 mm Weight: 910 kg Quill stroke: 180 mm Spindle to table distance: 190 – 650 mm Spindle to base distance: 1,310 mm Column diameter: 125 mm Table size: 400 x 420 mm Automatic feeds: 0.10 – 0.18 – 0.24 (3 steps) mm/min Motor speed: 750 – 1,500 RPM ERLO (MADE IN SPAIN) FOR DEMANDING WORKSHOP APPLICATIONS Drilling and milling machine Automatic feed Electromagnetic precision clutch Gear drive Cross table Fixed table and adjustable drilling head Operator control console Coolant supply with electric pump Hand wheel for fine adjustment Tool clamping device Lredoynmtxspfx Ah Ujl Adjustable stops Protective guard OPTIONS (PRICES ON REQUEST): Digital drilling depth display Thread cutting device Powered longitudinal and/or cross feed Digital display for table axes and/or drilling head height adjustment

Stanje: rabljeno, Funkcionalnost: popolnoma funkcionalen, moč: 5,5 kW (7,48 KM), Tip: R143 R82 DV132S-4TF Moč: 5,5 kW Hitrost motorja: 1430 obr/min Izhodna hitrost: ca. 4 obr/min Navor: ca. 10.000–12.100 Nm Napetost: 220Δ / 380Y Oblika konstrukcije: B3 Lrodpfjy T Ndxex Ah Uol Stopnja zaščite: IP54 Teža: ca. 500 kg

Stanje: dober (rabljeno), Leto izdelave: 1997, Also available: CONQUEST T51 model Lodpfovtrc Sex Ah Ujrl The used HARDINGE CONQUEST T42L 3-axis CNC lathe is a robust and precise medium-sized slant bed CNC lathe with an approximate turning length of 700mm, a bar capacity of 42mm, and a 12-position automatic turret with live tooling. It features a FANUC 18-T CNC control with a color LCD screen and an RS232 serial interface for data transfer. ASA 5″ spindle Max speed: 4,200 rpm Continuous C axis Spindle power: 20HP X-axis travel: 172mm Z-axis travel: 575mm Machine weight: 4,000 kg The machine comes complete with a 210mm AUTOBLOCK hydraulic chuck, tool presetting system, programmable tailstock, 2 live tool holders (1 axial and 1 radial), chip conveyor, a set of fixed and manual tool holders, and backup disk. Year of manufacture: 1997. CE compliant and in excellent condition.

Stanje: rabljeno, Leto izdelave: 2007, Turning diameter 300 mm Turning length 600 mm Control system FANUC, 18i-TB Swing over cross slide 230 mm X1-axis travel 165 mm Z1-axis travel 700 mm X2-axis travel 190 mm Z2-axis travel 720 mm Y-axis travel +/- 50 mm Main spindle bore 76 mm Main spindle speed 5,000 rpm Main spindle motor 22 kW Spindle torque 208 Nm Sub-spindle bore 76 mm Sub-spindle speed 5,000 rpm Sub-spindle motor 22 kW Spindle torque 208 Nm Turret 2 x 12 stations Number of driven tool stations 2 x 12 Driven tool speed 5,000 rpm Torque 47 Nm Tool drive power 5.5 kW C-axis resolution 0.001° Rapid traverse X + Z axes 20 / 40 m/min Rapid traverse Y-axis 7.5 m/min Total power requirement 68.4 kVA Accessories: Collet chuck KITAGAWA, CRS 66, on main spindle; Hydraulic 3-jaw chuck KITAGAWA, BB208, 210 mm dia., on sub-spindle; Various tool holders for turret; Short bar loader by HYDRAFEED, type MULTIFEED MX-1B for Lsdjy Tplijpfx Ah Ujrl bar diameters 3 - 80 mm and bar lengths up to 1650 mm; chip conveyor; Coolant system with belt filter unit

Stanje: rabljeno, Leto izdelave: 2011, Technical details: Standard turning diameter: 200 mm Turning length: max. 810 mm Control: MSX-701 MAPPS IV Swing diameter over bed: 800 mm Max. distance between centers: 1130 mm Max. turning diameter: 320 mm Max. workpiece diameter: 300 mm Bar diameter: 65 mm X-axis travel 1: 210 mm X-axis travel 2: 210 mm X-axis travel 3: 210 mm Y-axis travel 1: 110 mm (+65/-45) Y-axis travel 2: 110 mm (+45/-65) Z-axis travel 1: 300 mm Z-axis travel 3: 300 mm Z-axis travel 2: 810 mm B-axis travel: 870 mm Spindle speed range: 5,000 rpm Number of spindle speed ranges: 2 Spindle nose: JIS A2-6 Spindle bore: 73 mm Lrodpfx Ahjy S Tm Uo Ujl Spindle bearing diameter: 120 mm C-axis: 0.001° Spindle speed range: 5,000 rpm Spindle nose: JIS A2-6 Spindle bore: 73 mm Max. bar diameter: 65/52 mm Spindle bearing diameter: 120 mm C-axis: 0.001° Number of turrets: 3 Number of tool stations: 16 x 3 = 48 positions Shank height for square tool: 20 mm Shank diameter for boring bar: 32 mm Turret indexing time (4 stations): 0.18 sec Number of driven tools: 16 x 3 = 48 positions Max. speed of driven tools: 6,000 rpm Machining capacity of turning tool: M16 / Ø16 Rapid traverse X-axis: 30 m/min Rapid traverse Y-axis: 20 m/min Rapid traverse Z-axis: 50 m/min Drive power - spindle motor: 25 / 22 kW Drive power - driven tools: 7.5 / 5.5 kW Total power requirement: 92.7 kVA Machine weight approx.: 9.4 t Space requirement approx.: 4.0 x 2.8 x 2.4 m Accessories: Chip conveyor Coolant system C-axis main and sub spindle 2 x Y-axis Part counter Total counter Tool measurement system Parts catcher from above with conveyor belt Spindle 1: power chuck SMW KNCS-N 210 / 52 mm Spindle 2: collet chuck Hainbuch Spanntop nova Kombi Axfix 65 Robot interface Lehmann loading robot with infeed and outfeed conveyor for shaft parts The NZ2000 T3Y2 features 2 spindles and 3 turrets. Two turrets are equipped with Y-axis function and built-in milling motors. This enables simultaneous machining with 3 turrets. High-performance and high-speed machining can be achieved using up to 48 driven tools. For automatic loading, a Lehmann robot with infeed and outfeed conveyors for shafts is used. The machine has been maintained by the in-house maintenance department and Mori Seiki. The machine can also be sold without the robot.

Stanje: rabljeno, Leto izdelave: 1976, x-travel 350 mm y-travel 150 mm z-travel 340 mm Table clamping surface 600 x 210 mm Spindle taper SK 40 Spindle speeds 40 - 2000 rpm Feeds 5 - 500 mm/min Lredpewwwr Ejfx Ah Uol Rapid traverse 1.2 m/min Total power requirement 1.9 kW Machine weight approx. 0.7 t - Machine from training workshop - Accessories: fixed table, vertical head with extendable quill, 3-axis HEIDENHAIN digital readout, various short and long arbors, various collets, original DECKEL tool cabinet

Stanje: rabljeno, Leto izdelave: 1990, x-pomak 2800 mm y-pomak 1000 mm z-pomak 1200 mm Površina stola za stezanje 2000 x 800 mm Prečnik rotacionog stola 800 mm Prihvat vretena SK 50 Broj obrtaja vretena – besprekorno promenljivo 50 – 2000 o/min Obrtni moment na vretenu 3000 Nm Motor vretena 30 kW Posmaci – uzdužni/poprečni/vertikalni 2 – 2000 mm/min Brzi hodovi – uzdužni/poprečni/vertikalni 7 m/min Upravljanje SIEMENS Upravljanje SINUMERIK 850 M Broj mesta u magazinu alata 56 Prečnik alata pri punom kapacitetu 114 mm Prečnik alata sa 2 slobodna mesta 200 mm Maksimalna dužina alata 400 mm Lredpsyt Rwlofx Ah Uel Maksimalna težina alata 16 kg Vreme izmene alata cca 8 – 9 sek Unutrašnje dovod rashladne tečnosti da / yes Težina mašine cca 25,4 t - 5-osna CNC portalna glodalica sa integrisanim NC rotacionim stolom i NC glave za okretanje - Oprema: uređaj za predpodešavanje alata, razni alatni prihvati, transportera strugotine, sistem za rashladnu tečnost sa pumpom visokog pritiska i filterom, elektronsko ručno kolo, fiksatori