CNC grinding machine Supplier | Large Molds, Deep Cavities, RFQ Checklist

RFQ should provide material, hardness HRC50+, cavity depth > 80mm, roughness Ra ≤ 0.2μm and batch quantity, confirm spindle speed and cooling system configuration.

Large Molds

Rigidity & Shock absorption rate

Put a truck-heavy, 4-meter-long steel block on the grinding machine, ordinary metal base will be pressed out a 0.015 millimeter naked-eye invisible depression. Tiny sinking will let high-speed rotating grinding wheel deviate from original route 0.05 millimeter. Wait until this mold is installed on the machine to produce plastic parts, product surface will extra appear a 0.08 millimeter burr.

Manufacturers making large grinding machines give up using pure iron, like building houses casting "artificial stone" base. Workers put epoxy resin and four kinds of different thickness quartz sand according to 1 to 9 weight mixed, in sealed tank pump dry air. This piece of stone needs to in 25°C constant temperature room quietly lie for 28 days, thoroughly release internal pulling force.

Artificial stone absorbs vibration speed is traditional cast iron's 8 times. Base inside's every dimension, is all for carrying dozens of tons of heavy pressure and specially designed.

· Load-bearing bottom's thickness from common 25 millimeters thickened to 80 millimeters.

· Internal cross-supporting strengthening ribs thickness reaches 45 millimeters, presents 60 degrees included angle.

· Guide rail combining surface entirely relies on old craftsmen manually scraping flat, error controlled within 0.02 millimeter.

· Storing lubricating oil's groove spacing kept at 8 millimeters, forms a layer of stable oil film.

· Whole machine's center of gravity is dead-dead pressed at distance from ground less than 800 millimeters' height.

Diameter 600 millimeters' rough grinding wheel with per minute 3000 circles' speed smashes toward hardness up to HRC58's mold steel, contact instant produces 1500 Newtons' huge thrust. Intense friction will let whole machine produce per second hundreds of times' high-frequency shivering.

Base if not enough stable, grinding wheel will on steel block surface back and forth bounce, leave spacing 0.2 millimeters' dense water ripples. Preventing microscopic bouncing's hard indicator is, spindle at bearing 200 kilograms lateral thrust time, axis deviation amount cannot exceed 0.1 micrometer.

Assembly workers will use carrying digital display's torque wrench, use 600 N·m's strength to 8 high-strength bolts twist tight.

· Grinding wheel rotating time's weight unbalance feeling is limited at 1.5 grams·millimeter within.

· Sliding tracks between filled with thickness constant at 15 micrometers' oil film, cuts off metal friction.

· Cooling water spray pressure maintains at 20 bar, per minute washes away 120 liters iron chips and heat.

· Pushing machine table moving's linear motor thrust up to 8000 Newtons, reaction time less than two thousandths second.

· Transmission using's ball screw is in advance pulled long, per meter reserves out 0.03 millimeters' stretching amount.

Settling machine's workshop ground, must guarantee per square meter can bear 25 tons' weight, and one year's natural sinking amount cannot exceed 0.1 millimeter. Construction personnel at underground dig pit, cast 1.5 meters thick's C50 label high-strength concrete.

Machine surroundings dig out a circle 1.2 meters deep's shockproof trench, fill full fine sand and asphalt's mixture. This can put workshop inside 50 tons overhead crane passing time produced's low-frequency vibration blocked at outside 90% above.

Inspecting machine sturdy degree's method is take push-pull force gauge facing spindle push on 5000 Newtons' force. Beside placed can measure one thousandth millimeter's meter, as long as see any direction's displacement exceeds 0.005 millimeter, machine then not pass.

Bringing this bit deviation downward dig 500 millimeters deep's mold pit, tool then will happen bending deformation. Deformation lets mold bottom's dimension compared to opening place small 0.02 millimeter, completely cannot reach drawing required's 0.5 degrees tilt angle.

Testing shock absorption ability needs to put highly sensitive probe sucked on worktable, machine full speed running time, measured's vibration speed cannot exceed 0.2 millimeters/second.

· Machine continuously runs for two hours, bearing end face's tiny shaking must less than 1 micrometer.

· Suddenly press down emergency stop button, whole machine from shaking to completely still's time cannot exceed 0.5 second.

· Machine with per minute 20 meters' speed empty running time, anchor screw place's vibration feeling needs to be lower than 0.01G.

Grinding machine needs day and night not stopping to cut 300 to 500 hours, tool on steel block walked over's total distance exceeds 40 kilometers. Processed finished's dozens of tons mold two halves join together, hydraulic press applies 500 tons' strength press tight.

Two pieces of steel plates between's gap only has 0.015 millimeter's fault tolerance space. Gap once wanders to 0.02 millimeter, injection molding machine inside 280°C's high temperature plastic slurry water then will break through defense line spray surge and out.

Micrometer thermal deformation

A piece 3 meters long, 15 tons heavy's mold steel in workshop inside placing, room temperature every rises 1 degree Celsius, whole piece steel material will quietly stretch long 0.036 millimeter. Minuscule's 36 micrometers expansion amount, can let early stage consumed two weeks time finely carved and carefully polished's micrometer-level flatness totally become invalid.

Steel's linear expansion coefficient is fixed at 0.000012. Facing long as 72 hours' uninterrupted grinding task, spindle, motor and guide rail friction produced's heat ruthlessly bakes machine table on's giant metal. Let alone machine tool internal temperature difference not manage, one hour within will wildly soar 15 degrees Celsius.

Large CNC grinding machine's anti-heat system is like a heavy-duty precision air conditioner. Cooling power up to 25 kilowatts' industrial water chiller all-weather runs, puts equipped with special anti-rust agent's cutting fluid drops to constant water temperature. Large water pump with per minute 150 liters' huge flow rate, will ice-cool liquid splash in sparks flying all around's polishing area.

Cutting fluid's temperature fluctuation is dead-dead suppressed in plus minus 0.1 degrees Celsius' narrow interval within. Temperature measuring probe per second reads 10 times water temperature data, captures a trace of temperature deviation, variable frequency compressor starts to intervene freezing liquid's circulation flow rate. Taking away high temperature iron chips' liquid flows back to capacity reaching 2000 liters' sedimentation pool to conduct three-stage physical filtration.

Crazy running's machine tool spindle is whole device heat generation largest's a piece of area. Ceramic ball bearings with 3000 revolutions/minute's speed wildly run, metal friction surface's instant temperature breaks through 120 degrees Celsius. High pressure cooling oil pipes like blood vessels the same densely wrap on spindle outer shell and motor stator periphery.

· Circulating cooling oil's kinematic viscosity strictly locked at per second 2.5 square millimeters.

· Independent oil cooler's temperature controller set value closely sticks to workshop real-time room temperature, temperature difference less than 0.5 degrees Celsius.

· Linear motor's primary coil gap in spread full of diameter 6 millimeters' red copper water cooling pipes.

· Transmission ball screw inside is thoroughly hollowed out, normal temperature cooling oil in screw axis back and forth shuttles.

· Nut seat and high-precision bearing seat's installation surface on carved out maze-like's return water grooves.

Discharging away machine tool itself's heat generation only completes half task, placing machine table's surroundings air temperature all is strictly managed. Loading this giant grinding machine's constant temperature factory building, surroundings walls embedded thickness reaching 150 millimeters' polyurethane insulation boards. Top part's central air conditioning air outlet all installed with micro-hole diffusers, wind speed suppressed at per second 0.15 meters below.

Slowly sinking's cold air like a layer of thin gauze the same evenly covers at machine tool above. Factory building inside 24 hours' day and night temperature difference cannot be greater than 1 degree Celsius, space vertical direction on per meter's temperature difference less than 0.2 degrees Celsius. Entering and exiting factory building's double-layer interlocking air shower doors, put outdoor heat wave dead-dead blocked at door outside.

Assembly engineers in machine bed, column and spindle box's hidden corners, buried 24 high-precision PT100 platinum resistance temperature sensors. Highly sensitive resistance components can capture 0.01 degrees Celsius' weak heat change, put data continuously pass to CNC brain.

Computer motherboard inside's thermal compensation algorithm every interval 10 milliseconds calculates out every direction's microscopic expansion amount. Digital instructions control X, Y, Z three moving axes' servo motors, toward reverse direction secretly step back a few micrometers. Reverse fine-tuning action filled flat steel heated stretching squeezed out's dimensional deviation.

Rough grinding wheel on workpiece surface back and forth frictions 100,000 times after, spindle in Z-axis direction on's thermal stretching amount always stays at 0.01 millimeter within. Processed finished's mold surface temperature, use infrared thermometer gun shot out's numerical value and before dropping tool only has 0.3 degrees Celsius' tiny drop.

Consumed time half a month finely polished's large mold is transported into three-coordinate constant temperature measuring room. 20 degrees Celsius' room temperature under, ruby probe in mold cavity inside samples points records down 5000 three-dimensional coordinates. Report sheet on's dimension profile degree numerical value steadily parks at 0.005 millimeter's pass line within.

Spatial accuracy

On a root long as 4 meters' cast iron track, let heavy as over ten tons' metal sliding table from one end walk to another end, maintain a strip absolute straight line's movement trajectory is very strenuous. Sliding table every forward moves 100 millimeters, produces 0.001 millimeter's up and down undulation, accumulated to 4 meters end also will become naked-eye visible's tilt.

Heavy grinding machine's guide rail does not rely on machine polishing, entirely relies on fitter master holding scraper little by little manually scraped out. Coated full red lead powder's metal surface is scraped out countless tiny pits, use naked eye look over is like a piece of fine and dense fish scale pattern.

Inspecting scraping craft's ruler is a piece heavy as 50 kilograms, experienced three years natural aging treatment's granite straight edge.

Straight edge sticks to guide rail surface back and forth frictions, revealing out red color's high points then are by scraper precisely shaved off. Every piece 25 square centimeters' area on, must evenly distribute at least 25 contact points. 4 meters long's X-axis guide rail whole journey straightness error is forcibly pressed at 0.003 millimeter within.

Control system has a very precise ruler stuck at machine tool beside. Germany produced's fully closed-loop absolute value linear scale is tightly locked at X-axis and Y-axis' side face, glass ruler body on carved full of dense stripes.

Reading head suspends at glass ruler above 0.5 millimeter's height, following sliding table high-speed moving, per second reads out tens of thousands of position signals. Linear scale's resolution reached 0.0001 millimeter, equivalent to one root hair silk diameter's one percent.

Several tons heavy's workpiece on worktable fast goes back and forth, inertia puts linear scale's reading head toward back pulls.

· Linear scale outer shell adopts expansion coefficient extremely low's Invar material, long as 4 meters' ruler body under temperature change's stretching amount less than 1 micrometer.

· Reading head inside's light-emitting diode shoots out light beam, penetrates glass carved lines forms Moiré fringes.

· Photoelectric receiver puts stripe change converts into electrical signal, cable with one millionth of a second's speed passes back to computer motherboard.

· Controller as long as discovers sliding table less walked 0.0001 millimeter, will increase motor's current to put position compensated on.

Three moving axes pieced together, in length width height each 3 meters' three-dimensional space inside cutting metal, error will present geometric level amplification. X-axis' tiny yaw, Y-axis' slight head lowering, Z-axis' subtle swinging, 21 items spatial geometric errors overlay on grinding wheel on.

Machine tool assembly finished, engineer pushes come a dual-frequency laser interferometer. Laser transmitter shoots out a beam of red laser, hits on fixed at machine tool spindle on's reflector on, refracts back to receiver.

Laser beam's wavelength is fixed at 632.8 nanometers, became space inside most straight's scale. Machine according to computer instructions, every interval 50 millimeters pauses one time, records down actual position and theoretical position's deviation. 3 meters' stroke is cut into 60 measuring nodes, interferometer collected's data forms a strip of wave undulating's error curve.

Computer motherboard inside's pitch error compensation function starts to intervene. If laser interferometer measures out at 1.5 meters' position, machine more walked 0.002 millimeter, CNC system then puts this data writes into bottom layer's compensation matrix inside.

Next time grinding wheel runs to this exact position time, servo motor secretly toward back retreats 2 micrometers' distance, puts mechanical assembly brought's physical error abruptly eats away. A set of compensation process consumes engineer full two days time, generates exceeding 1000 nodes' data package.

Column high as 2.5 meters' grinding machine, top end carrying hundreds of kilograms' spindle box back and forth moves, unavoidably produces Abbe error. Spindle box inside's grinding wheel center and bottom's linear scale between differ by 1.2 meters' vertical distance.

Saddle on guide rail produces even if 0.5 arc seconds' tiny rolling, 1.2 meters' height difference will put this rolling magnify into grinding wheel tool tip on's 0.003 millimeter's position offset.

· Two Y-axis guide rails between's distance from conventional's 800 millimeters is pulled wide to 1200 millimeters.

· Four long as 200 millimeters' heavy-load roller sliding blocks dead-dead bite guide rail, bear coming from four directions' twisting force.

· Z-axis column adopts double A-shaped structure, inside spread full of honeycomb-like's strengthening ribs, bottom uses 12 M24 bolts anchored at machine bed on.

Installed with large dimension grinding wheel's spindle in space inside walks out a diameter 500 millimeters' circular trajectory. Roundness measuring instrument sticking to test-cut well's steel block inner hole scans one circle, screen on printed out's radar chart is a concentric circle, runout amount at 0.004 millimeter within.

Processing heavy as 20 tons' wind power blade mold time, machine tool often needs three axes simultaneously move, walk out a strip of spatial three-dimensional curve. System processor's calculation cycle shortened to 0.25 milliseconds, per second can to three motors send 4000 position instructions.

Three axes' movement must like gear meshing the same precisely synchronize. X-axis compared to Y-axis late started 1 millisecond, mold surface's curve then will bulge up a 0.01 millimeter's tiny spike.

Deep Cavities

Processing variables

A piece 200 millimeters thick's H13 steel block put in machine tool inside, tool just touches metal's that instant, will produce nearly 800 Newtons' thrust. A root length is diameter 15 times' carbide milling cutter, receives force after tool tip will toward side deviate out 0.08 millimeter. Machine tool spindle one minute rotates 15,000 circles, tiny deviation follows crazy flinging. Wall on is knocked out deep and shallow uneven's ripples, height difference exceeds 15 micrometers.

Originally tool tooth every bites one mouthful can eat away 0.15 millimeter's metal, forced down to 0.03 millimeter below. Alone doing this one piece of work, rough processing time from 14 hours abruptly dragged to 60 more hours. Machine tool spindle inside's bearing follows long time receiving force, usage life lessed full 30%.

H13 mold steel factory hardness at HRC 30 around. Experienced heat treatment quenching, hardness soars to HRC 52. Hardness every upward walks 2 degrees, tool eats away 1 cubic centimeter metal needs to more spend 20%'s strength. Pit bottom corners inside easy to hide hard points, hardness approaches HRC 55. Tool tip meets hard point's one instant, impact force multiply increases.

Tool tip with iron block intensely frictions, 0.2 seconds within temperature shoots up to 900℃ above. From outside toward inside sprays cooling water, water flows to 50 millimeters deep's pit bottom time, speed even per second 0.5 meters all not reach. Tool rotates very fast, surroundings forms a circle of air wall. Slow cooling water squeezes not in, heat all is stuffed at underneath.

Experienced extreme heat extreme cold alternating, tool blade surface's coating cannot bear it. Continuously cut for 45 minutes, carbide inside's cobalt component becomes brittle, surface cracks open naked-eye invisible's mesh fine lines. Put at microscope under measure, front tool face on's pit as long as exceeds 0.04 millimeter deep. Next one time cutting, 80% above's probability will chip and break.

· Tool edge defect length greater than 0.02 millimeter

· Tool back wear width exceeds 0.3 millimeter

· Surface layer coating drops area occupies 15%

· Iron chips color burns into deep blue or purple

Dropped at pit bottom's iron chips, thickness normally at 0.05 millimeter to 0.15 millimeter between. They roll together discharge not out, in narrow gap inside follow tool blade rotate, put just scraped flat's inner wall again scratched flowered. Originally Ra 0.8 micrometer's smoothness, a blink of an eye becomes rough's Ra 3.2 micrometers. Polishing workers must spend normal time 5 times' strength to polish.

Change onto carrying center hole's tool, machine tool water pump shoots out 100 Bar's high pressure. Cooling water following tool shank inside two diameter 1.2 millimeters' fine holes downward rushes. Water flow with per second 80 meters' speed from tool tip toward outside sprays. Several grams heavy's iron chips are by rapids swept along, forcibly upward pushed 150 millimeters rushed to pit outside.

Put tool blade's angle changed into 45 degrees, cut down's iron skin becomes thinner and narrower. Thrust no longer horizontally tosses tool shank, following tool shank downward presses, bending deformation's strength lessed 30%. Tool blade edge at microscope under wears blunt 5 to 10 micrometers.

· Iron chip curling angle controlled at 15 degrees inside

· Cut groove width at 0.8 to 1.2 millimeters

· Hold iron chip gap ratio greater than 60%

· Discharge out of pit speed greater than per second 5 meters

Cutting produced's heat following iron part toward upward passes, machine tool spindle outer shell follows gets hot. Thermometer every upward climbs 1℃, spindle metal parts downward stretch long 12 micrometers. Dig a 300 millimeters deep's pit, machine tool continuously runs 8 hours. Thermal expansion and cold contraction accumulate up, pit bottom more dug away 0.05 millimeter.

Computer programming time, every time downward walking's distance locked dead at 0.12 millimeter. Tool head not straight up straight down, like going down spiral stairs the same making circles downward walks, tilt angle controlled at 1.5 degrees to 3 degrees between. Machine tool three directions simultaneously move, maintain per minute 1200 millimeters' speed. Encountering corner not decelerate pause, prevent tool blade at original place idle running cut more.

Clamping tool's chuck, dynamic balance satisfies G2.5 level. Plus extension rod altogether 1.5 kilograms heavy, at one minute 24,000 revolutions' speed under. Even if only deviated one side 0.5 grams, flings out 180 Newtons' centrifugal force. Vibration passes to bottommost's tool tip, metal surface is vibrated out 0.02 millimeter wide's fish scale fine lines.

Semi-finishing processing time, wall on leaves 0.15 millimeter's metal. Change onto a piece diameter 8 millimeters' round head tool, sticking to wall root circle by circle scrapes. Every time downward only walks 0.05 millimeter, machine tool screen on's load number dead-dead pressed at 15% below.

· Entering tool drawing circle radius greater than 4 millimeters

· Walk to corner speed drops to 40%

· Two rows tool paths overlapping's place occupies 35%

· Toward upward lift tool withdraw maintain 50 millimeters distance

Dug to 400 millimeters' bottom, flatness drawing on marked 0.005 millimeter. Five-axis machine tool holding probe at pit bottom pokes 9 dots, generates a piece of undulating grid. Laser instrument measures out tool real diameter is 10.002 millimeters. Machine tool system calculates finished account changes data, steadily cuts finished last that 0.03 millimeter.

Equipment & Process

12 tons' mineral casting machine bed shock absorption ability is ordinary cast steel's 6 to 10 times. Tool at 400 millimeters deep's pit bottom shivers, vibration passes to machine bed on is abruptly eaten away 85%. Even if territory passes a 5 tons' heavy forklift, machine bed table on's dial indicator pointer even half grid all will not shake.

Machine tool belly inside's lead screw every day high-speed back and forth frictions generates heat. Advanced equipment puts lead screw middle hollowed out, toward inside hits in 18℃'s constant temperature cooling oil. Oil liquid with per minute 15 liters' speed non-stop circulates, puts metal surface's temperature dead-dead pressed at room temperature up down 0.2℃'s interval inside. A root 1500 millimeters long's lead screw, thermal expansion is forcibly stuck at 0.003 millimeter within.

Heat-shrink tool holder put into heating machine inside baked to 300℃, hole diameter instantly expands large 0.02 millimeter. Workers put tool stuffed inside, wait metal cools contracts, several thousand Newtons' grip force dead-dead hugs tool shank. Spindle rotation speed pulled to per minute 20000 revolutions, tool tip's deflection amplitude is bitten dead at 0.003 millimeter within.

Mold original embryo clamped at worktable on, bottom padded 4 pieces hardness HRC 60's flat mouth pad irons. Worker holding torque wrench, puts M20's pressing plate bolts all twisted to 120 N·m's dead numerical value. Hundreds of kilograms' steel block once receiving force not even, will produce several micrometers' twist. Dug finished hundreds of millimeters' deep pit to loosen bolts, internal stress release will let whole pit bottom warp up 0.05 millimeter.

Machine tool processing cabin inside's cutting fluid spray pipes as many as 12 roots, water column pressure reaches 8 MPa. Water flow not randomly sprays, intersection point all concentrated at tool tip toward upward 20 millimeters' narrow interval. Strong water net at pit bottom forms micro vortex, puts more than ten grams heavy's whole clump iron chips rolled up toward outside throws. Iron chips at cavity bottom's stay time absolutely not exceeds 2 seconds.

Length-diameter ratio exceeds 20 to 1's narrow slit, lengthened milling cutter fundamentally extends not in, electric discharge machining (EDM) equipment takes over doing work. A root 0.5 millimeter thick's red copper sheet connected on positive pole, mold steel block connected on negative pole. Two both middle separated by 0.02 millimeter wide's spark oil layer, releases out tens of thousands of volts' high pressure electric arc.

Tens of thousands of degrees' high temperature electric arc, one instant puts H13 steel burned into naked-eye invisible's vaporized micro-particles. A piece 50 millimeters deep, 2 millimeters wide's dead corner bottom groove, relies on discharging little by little downward bites. Machine tool set per second discharges 50000 times, every strike only bites away 0.0001 gram metal. Red copper electrode follows consumes, tip every downward hits 1 millimeter, self needs to become short 0.08 millimeter.

· Red copper electrode surface finish must reach Ra 0.2 micrometer

· Discharge gap forcibly maintained at 0.015 to 0.03 millimeter

· Flushing oil pressure adjusted to 0.8 MPa to put waste residue toward outside blow

· Electrode up down jumping discharge residue frequency per second acts 3 times

· Rough hitting and fine hitting change two sets dimension differ 0.1 millimeter's electrodes

A large mold needs to equip thirty forty red copper electrodes. Worker uses three-coordinate measuring instrument to every electrode measures well three-dimensional dimension. X, Y, Z three directions' data error once exceeds 0.002 millimeter, hit out's pit all ruined. Carrying chip's tool holder seat puts data saved down, mechanical hand grabs up electrode toward spindle on one stuff, saves away tool setting finding zero point's effort.

EDM spark machine discharging's oil tank inside loaded full synthetic oil, kinematic viscosity dead-dead controlled at 2.0 around. Processing depth walks to 150 millimeters, oil tank bottom's suction pump with per minute 50 liters' flow rate toward outside wildly pumps. Filter element pore size fine to 5 micrometers, puts mixed in oil inside's black carbon powder and metal residue filtered completely clean.

Fine hitting bottom corner's stage, ammeter on's ampere number adjusted low to 0.5 ampere. Pulse width shortened to single digit microseconds, red copper electrode sticking to steel surface relies on weak electric spark slowly licks. Processing 1 square centimeter's area consumes full 45 minutes. Left at pit bottom surface's roughness reaches mirror level's Ra 0.1 micrometer, fingerprints all can shine clearly.

Machine corner inside installed laser tool setter. Tool just from deep cavity inside pulled out, runs to infrared light beam inside turns one circle. Light beam measures out tool tip after all worn how many micrometers, data once crosses beforehand set's 0.03 millimeter warning line, system instructs tool magazine change a piece new tool. Not cross line, system calculates out difference value, in next one tool's code inside secretly compensates on 0.015 millimeter's depth.

Equipment & Inspection

A piece 600 millimeters wide's mold steel, inside outside temperature difference differs 3℃, inside holding back dozens of micrometers' deformation. Workers put it moved into constant temperature room, air conditioner air vent all year round set at 20℃. Hundreds of kilograms' iron lump needs to at cast iron platform on quietly lie full 24 hours, wait inside outside temperature completely consistent, stress thoroughly released.

Thermometer probe sticks at steel block surface, reading continuously 2 hours not jump even if 0.1℃, just counts as truly cooled down.

Measuring deep pit inside's dimension, three-coordinate measuring machine is only's ruler. Measuring head needs to probe into 300 millimeters deep's hole bottom, must install on a root carbon fiber material's extension rod. Carbon fiber weight only is steel's one fourth. Spindle taking it with per second 200 millimeters' speed moves, flung out's inertia error small to almost ignore not count.

Extension rod front end picking a piece diameter 0.5 millimeter's ruby measuring ball. Measuring ball touches pit bottom's one instant, internal piezoelectric sensor feels 0.05 Newton's weak resistance. Sensor puts electrical signal sends to computer. Machine tool linear scale captures this one thousandth second's three-dimensional coordinate, three directions' numbers precise to decimal point after four digits.

Long rod extends more long, gravity caused's sagging more severe. A root 200 millimeters long's carbon fiber rod, end will naturally sag 0.003 millimeter. System software in advance ran over calibration program, remembers this 3 micrometers' deviation. Ruby touches pit wall, computer in background quietly puts sagging amount adds back go, screen on jumps out's dimension fraction not differ.

Deep pit bottom's a circle R corner is drawing on dead knock's place. Drawing requires R3.0's circular arc, tolerance only has 0.01 millimeter. Ordinary round ball measuring head extends not in narrow corner, master changes onto star-shaped measuring stylus. Four directions extend out four 0.3 millimeter's small balls, like octopus the same drill into dead corner. Measuring stylus with per second 5 points' speed densely touches, computer inside pieces out a perfect's circular arc profile.

· Measuring ball roundness error lower than 0.00025 millimeter

· Measuring head trigger lifespan exceeds ten million times

· Carbon fiber rod thermal expansion coefficient only is 0.5 micrometer per degree

· Measuring machine air bearing guide rail air supply pressure maintains at 0.4 MPa

Optical profilometer is mounted at deep pit right above, a beam wavelength 633 nanometers' red laser hits toward bottom. Lens through interference fringes' sparse and dense, calculates out surface naked-eye invisible's high low undulating.

Pit bottom reflection too strong will let laser dazzle eyes, read out's numbers all turn into garbled characters. Worker at pit bottom sprays on a layer thickness only has 2 micrometers' imaging powder. Originally like mirror the same's surface covered on a layer of matte white. Laser sweeps past, one second grabs 3 million point cloud data, computer screen on instantly builds up a seat carrying tiny wave peaks wave valleys' 3D mountain range.

Roughness Ra 0.2 micrometer's surface, on point cloud map is magnified into high low drop less than 1 micrometer's hilly area.

Dug to 400 millimeters' deep hole, flashlight light beam hits not in innermost. Industrial endoscope following hole wall slides in. A root diameter 4 millimeters' snake-shaped soft tube front end, installing a piece 2 million pixels' micro camera. Tube surroundings surrounded 6 pieces high brightness LED light beads, puts narrow dark's pit bottom shined deadly white.

Screen on appears a piece length width each magnified 50 times' area. Several strips subtle's mesh cracks hide in corner inside, width only has 0.01 millimeter. This is carbide tool blade chipped after, on steel surface forcefully pulling hard dragging left down's dark injury. Let alone not manage, mold in die casting machine inside bearing 800 tons locking force time, will from this 0.01 millimeter's crack place thoroughly explode open.

Measuring cavity wall thickness used on ultrasonic thickness gauge. Probe coated on coupling agent sticks at mold outer wall, emits out frequency is 5 megahertz's high frequency sound wave. Sound wave penetrates 50 millimeters thick's steel wall, bumps to deep pit inner wall bounces back come. Instrument pinches accurate sound wave ran a round trip's 7.8 microseconds time, calculated out's wall thickness error dead-dead stuck at 0.02 millimeter within.

RFQ Checklist

Drawing & Technology

Handed over's 3D file sends STEP AP214 protocol version or NX native's .prt file. 2D drawing according to 1:1 ratio outputs drawing, title block marks clear using first angle or third angle projection drawn. Those not with other parts touching together's places, dimension difference ±0.05mm to ±0.1mm all can do.

Assembly contact surface's dimension is stuck very strictly. Flatness forced needs to do to every 1000mm only has 0.002mm's undulation, perpendicularity set at 0.005mm. Mold bottom surface acts as datum A, long edge's guide pillar hole counts as datum B, short edge right middle is datum C, all according to IT5 or IT6 national standard walk.

· A datum surface needs to use manual scrapes out per square inch 25 contact points

· B and C two datum holes eccentricity cannot exceed 0.003mm

· Dowel pin hole's gap all according to H7/g6's assembly table to do

· Upper lower molds joined together's place leaves 0.02mm uses hand slowly polishes

· Hiding screw cap's counterbore hole requirement relaxed to ±0.15mm

Ejector pin back and forth friction's place requires roughness 0.2, deep cavity inside forming's surface needs to polish to looking mirror the same's 0.05. Drawing on draws clear polishing texture's direction, grinding wheel walking tool's trace must with plastic part withdrawing out's direction parallel.

Cavity inside has how slanted needs to mark specific's draft degrees. Surroundings side walls slant 1.5 degrees to 2.5 degrees, bottom corner place draws R1.5 or R2's circular arc. Cavity bottom if has a not through's blind hole, beside must draw a strip 5mm to 10mm wide's tool withdrawal groove, avoiding tool hits on go.

Operating machine tool's master looking at these R corner data goes to pick grinding wheel. Encountering R1.5's corner, then takes edge dressed to 1.2mm below's cubic boron nitride grinding wheel to polish. 2D drawing beside attaches a piece section view, marking clear machine tool spindle descends to 400mm deep's time, from beside still needs to empty out 2.5mm above's safe distance.

Easy to happen interference's place on drawing on strikes on single slash shadow. Rough polishing's time every walks one tool cuts 0.01mm, fine polishing every tool only allowed to cut 0.001mm. Drawing remarks column writes on a stroke, uses single crystal diamond pen every polished finished 3 parts then must dress one time grinding wheel.

· Drawing writes clear three-coordinate measuring instrument must sweep's 75 spatial positions

· Deep cavity inner wall per square centimeter picks 3 points to piece out whole surface's shape

· Change onto 0.5mm ball diameter's ruby measuring stylus to touch all's R corners

· Measuring room air conditioner temperature set dead at 20.0 degrees Celsius

· Measuring's equipment error cannot be bigger than 1.5 micrometers

H13 steel material marks clear goes to vacuum quenching, adds on three times high temperature tempering, surface hardness reaches Rockwell 52 to 54. Tungsten carbide wear-resistant block inside's cobalt component writes clear 12%, actual measured hardness maintains at 88 to 90.

Dozens hundreds of catties' iron block needs to mark clear lifting hole at where. M24 or M30's threaded hole hits at center of gravity connecting line two ends, hole depth is thread width's 1.5 times. Drawing on needs to draw out base four corners padding anti-deformation iron block's position, every piece receiving force area at 50mm×50mm above.

Exceeding 2 tons heavy's bottom plate equips on a set anti-deformation method. Requires machine tool worktable places on 6 carrying hydraulic pressure's flexible support pillars. Workpiece surroundings taking pressing plate fixing time's torque set at 120 N·m, prevents clamping too tight letting mold bulge up a few micrometers.

· Slow wire walking wire cutting cut finished leaves 0.15mm's thickness gives behind repairing smooth

· Bottom rough milling left down's tool mark depth pressed at 0.02mm within

· Drawing marks clear part enters fire furnace baked finished will shrink water 0.08mm

· Deep cavity side wall in advance hits well M8's thread bottom hole carries on 1.5mm chamfer

Grinding wheel rotation speed set at per second 30 to 35 meters, avoids deep cavity underneath too hot puts steel material burned soft. Spraying cold water's water pipe faces cutting's place, per minute outputs water 60 liters, water pressure opens to 0.8 to 1.0 MPa.

Hole deep's place separately writes a 0.002mm's cylindricity. Encountering hole diameter 20mm deep 150mm's blind hole, marks clear uses 16mm thick's lengthened grinding rod, length is width's 10 times. Machine tool spindle rotating up's eccentricity amount at doing work before adjusted to 1 micrometer within.

Step hole's position concentricity draws a 0.004mm's circle. From top on to step underneath's depth difference controlled at ±0.01mm. Blind hole underneath opens a strip 2.5mm wide, 1.5mm deep's groove, water flows in can put iron powder smoothly flush out.

Stroke & Load-bearing limit

Put a piece heavy as 3.5 tons, outline dimension at 1200mm×800mm×600mm's H13 steel block places on machine tool, worktable's physical deformation is first step test. Machine tool manual on marked's maximum static load-bearing if is 4 tons, placed on this piece steel billet after, worktable center's downward concave amount will reach 0.015mm.

Pressing plate, bolts and fixture's weight occupies workpiece own weight's 15% to 20%. A piece 3.5 tons' mold, matching's clamping pieces heavy as 600 kilograms, total weight approaches 4.1 tons' equipment limit. Hydraulic guide rail inside's oil film bears huge squeezing, 30 MPa's pump pressure under, originally 12 micrometers thick's oil film will be pressed thin to 8 micrometers.

Grinding machine XYZ three axes' activity space is not looking at worktable has how wide, needs to calculate grinding wheel can run how far. Part long 1200mm, X-axis' effective stroke at least must have 1500mm. Grinding wheel from part left side cuts in before, needs to leave out 150mm's acceleration starting distance, right side polishes out edge after needs to reserve 150mm's buffering braking area.

Encountering length width reaching 1800mm×1400mm's large front bumper mold base, Y-axis' span became hard indicator. Single column machine tool's cantilever extending out 1000mm after, end's sagging amount will exceed 0.03mm. Requires changing using double column gantry grinding machine, two roots columns spacing guaranteed at 2200mm, crossbeam up down lifting time's two ends synchronous error pressed at 0.005mm within.

Deep cavity processing to Z-axis stroke's squeezing extremely harsh. Part height 600mm, cavity deep 350mm, plus installed at spindle on's lengthened grinding rod long 400mm, Z-axis' total stroke must be bigger than 1350mm. Spindle shrinks to highest point time, grinding wheel bottom from workpiece highest point only has less than 50mm's gap.

Organize a copy equipment capability check list sends to factory, uses table to fill data compared to oral asking useful much. Factory fills finished below's table stamps returns back, equipment hard indicators clear-clear-chu-chu.

Single piece 5 tons' bottom plate, equips on double head sling and shackle, overhead crane's rated lifting weight must marked 10 tons. Hook descending's speed adjusted to lowest's per minute 0.5 meters, lightly touches on worktable, prevents tens of thousands of Newtons' impact force puts machine tool's hydrostatic guide rail smashes out pit.

Foundation's bearing capacity decides several micrometers' processing error. Heavy as 30 tons' gantry grinding machine adds on 5 tons' part, requires workshop floor's load bearing capability reaches per square meter 10 tons. Equipment beside needs to dig 1.5 meters deep's shockproof trench, fill full fine sand reduce vibration, isolate 50 meters away punching machine working time passed come's low frequency vibration.

Several tons heavy's steel block on worktable with per minute 15 meters' speed back and forth runs, inertia big astonishingly. X-axis servo motor's thrust needs to reach 5000 Newtons, just can pull hold this piece giant iron lump. Machine tool parameter inside needs to write clear, carrying load situation under's reversing acceleration set at 0.5m/s², too fast will let ball screw nut inside's steel balls instantly shatter.

Cutting fluid's supply system facing big size workpiece must match large power configuration. Part surface area expanded to 2 square meters, 50 liters capacity's small water tank supports not to ten minutes then will hot getting burning. Needs to change onto capacity exceeding 800 liters' large water sink, equips on power 3000 watts' refrigerator, puts cutting fluid's temperature dead-dead bites at 20.5 degrees Celsius.

Machine tool guide rail's lubricating oil consumption amount follows load bearing's increase multiply toward upward rises. Originally one hour drips 50 milliliters guide rail oil, pressed on 4 tons heavy's mold after, oil injector's frequency adjusted high to per hour 150 milliliters. Not by cutting fluid flushed away's waste oil mixed in water tank inside, list inside marks clear adds install carrying oil scraping disc's oil-water separator, one hour skims away 3 liters waste oil.

Part at table surface on placing's center of gravity position has clear fastidiousness. Heavy as 4.5 tons' irregular insert, center of gravity biased toward left side 300mm, makes machine tool left side guide rail's receiving force compared to right side more out 800 kilograms. On drawing on marks out center of gravity coordinate X:450 and Y:320, lets master puts heavy's one end aligning worktable right middle, places on counterweight block finding flat.

Load bearing test divides into static and dynamic two kinds working conditions. Heavy as 4 tons' steel block still placed on table surface time, measuring dial indicator pointer only deflected 0.005mm. Table surface with per minute 20 meters' speed running up, movement brought's downward pressing inertia force will let deflection amount soar to 0.025mm. In acceptance document inside writes clear requires issuing dynamic loading test's actual measured data.

Encountering carrying step's complex cavity, Z-axis downward probing's distance every increases 100mm, spindle end part's radial runout amount then will magnify one time. At overhanging length reaches 350mm time, spindle head's vibration amplitude measured out is 0.008mm. This string data will original seal not movingly duplicate to part's surface, becomes naked-eye visible's wave shape tool marks.

Inquiry sheet inside must stuff in several items equipment hard parameter indicator checking items.

· Spindle motor rated power greater than 22kW, to cope with 150mm wide grinding wheel's heavy cutting resistance

· Z-axis ball screw pre-stretching amount adjusted to 0.03mm, offsets 200 kilograms grinding wheel rack own weight brought's gap

· Fixture platform itself's parallelism repaired polished to every 500mm span less than 0.003mm

· Worktable hydrostatic guide rail's oil tank equipped on independent 500W water chiller unit controls temperature

· Equipment whole machine weight exceeds 25 tons, uses own weight presses hold high frequency vibration

Z-axis in up down 800mm's range inside slides, gib and guide rail between's oil film thickness maintains at 0.01mm up down. Gap loosens to 0.03mm, grinding wheel at cutting into steel material's instant, whole spindle will toward upward bounce 0.015mm. Processed out's deep cavity bottom surface will leave down a strip depth 0.02mm's connecting tool mark.

Grinding large cylindrical counterbore hole, X-axis and Y-axis need to draw a true circle. Two roots axes linked walking out a diameter 400mm's circle, speed set at per minute 800mm. Uses Renishaw ballbar at empty load under measured out's roundness error is 0.002mm, placed on 3.5 tons' load after, error is pulled magnified to 0.006mm.

Material & Process

Put H13 mold steel sent on grinding machine before, quenching process left down's bottom decides grinding wheel's loss rate. Vacuum furnace inside came out's steel surface carries a layer 0.03mm to 0.05mm thick's decarburization layer, this place hardness drops to HRC 40 up down. Grinding wheel touches on soft material, emery particles are dead-dead stuck, originally can do 20 pieces' grinding wheel, polished finished 3 then must take go re-dress.

Drawing material column inside fills on SKD11, rear attaches quantitative hardness requirement HRC 60-62. Heat treatment factory sent come's assay report sheet on, needs to stare tight core part hardness data, inside outside hardness difference once exceeds HRC 2 degrees, 1.5 tons heavy's steel billet at receiving force time will produce tiny's twisting deformation.

Heat treatment residual's austenite is hidden in steel internal's hidden danger. Document on needs to mark clear requires experiencing negative 120 degrees Celsius' deep cold treatment, puts excess's austenite turns into martensite, prevents part leaving factory three months after self-expands large 0.01mm.

Powder metallurgy high-speed steel ASP23's carbon content up to 1.28%, internal filled full hard's carbide particles. Take ordinary white corundum grinding wheel to rub, one minute not reach grinding wheel surface then is scraped flat. Inquiry list inside needs to write on a stroke, specify equipped ceramic binder's CBN grinding wheel to gnaw hard bone, cutting linear speed pulled high to per second 45 meters.

Facing containing cobalt amount reaching 15%'s tungsten carbide hard alloy, conventional grinding machine even skin all rubs not broken. Needs to change onto D126 grit's diamond grinding wheel, single time cutting depth limited at 0.005mm. Tungsten carbide extremely fragile, grinding wheel entering tool speed fast out 0.1 millimeter per second, workpiece edge will on spot chip away a piece 0.2mm's gap, tens of thousands yuan's material turns into waste iron.

Previous one process left down's messy stall, entirely relies on grinding machine to wrap up. Slow wire walking wire cutting cut finished's cross section, surface covers a layer 0.02mm thick's white cast layer. Waste material experienced tens of thousands degrees high temperature's electric spark burning melting, surface hardness soars to HRC 65 above, internal spread full of tiny's thermal cracks.

Grinding machine master takes over doing work time, first tool down tool must enough deep, one breath eats away 0.03mm, puts carrying cracks' waste layer thoroughly shovels away. If only down tool 0.01mm, grinding wheel purely at hard shell on slips, friction produced's three four hundred degrees high temperature following cracks toward part internal drills, puts underneath's good steel material burns out strip by strip 0.1mm deep's black marks.

Part at milling machine on's rough processing allowance cannot blindly leave. A piece length width 800mm×600mm's bottom plate, surroundings left 0.5mm's thickness, middle concave down's place only left 0.1mm. Grinding machine on uses big water grinds flat walks one tool past, four sides receiving force extremely big, whole piece steel plate receiving force not even, from machine tool on unloaded down like potato chip the same warps up 0.03mm.

Giving grinding machine leave single side 0.2mm to 0.3mm's allowance most is steady. Uses vernier caliper to measure sent come's blank, peripheral dimension thick thin difference needs to stick at 0.05mm within. Allowance east one side thick west one side thin, grinding wheel a while strenuous a while idle runs, polished out's part surface spread full of 0.002mm deep's wave lines.

· Quenched after's mold according to standard put into 200 degrees Celsius' tempering furnace inside baked 4 hours eliminates stress

· Rough milling processing uses large fly cutter disk walks tool, single tooth feed amount pressed at 0.15mm prevents cutting heat accumulation

· Carrying R1.2 round corner's deep cavity groove, wire cutting pre-left's corner waste thickness must not exceed 0.05mm

· Slender shaft class's ejector pin parts, entering grinding machine before needs to at straightening machine on puts bending degree press back 0.02mm within

Part parts need to carry magnetism, part must demagnetize. Containing nickel amount high's stainless steel material, electromagnetic chuck fundamentally sucks not hold, opening 150 volts' full load voltage only produces less than 20 Newtons' suction. List inside requires factory utilizes vacuum chuck or mechanical flat mouth vise to fix, lateral clamping force adjusted to 800 kilograms, prevents high-speed rotating's grinding wheel puts part flung fly out of worktable.

Containing carbon amount 0.45%'s S45C medium carbon steel magnetically conducting effect extremely good, completed taken down time, surface can suck up quite a few roots paper clips. Drawing inside needs to write on demagnetization requirement, puts residual magnetism pressed to 2 Gauss below. Demagnetized not clean's magnetic force puts air inside's iron powder all sucked over, assembling mold slightly happens friction, will on mirror surface scratch out a strip 0.05mm wide's mark.

Polishing blind hole internal, iron chips discharge not out, entirely relies on cutting fluid toward outside flushes. Requires puts water pipe nozzle changed into inner diameter 2mm's high pressure fine tube, probes into leaving hole bottom only remaining 5mm's gap inside strongly flushes.

Done over nitriding treatment's H13 steel, surface layer 0.15mm's thickness inside permeated full nitrogen atoms. Outer shell hardness rushes to Vickers HV 1000, compared to originally's steel material hard out one time more. Grinding thick hard shell time, sparks from dark red become bright white, cooling liquid flow rate valve opened to per minute 80 liters, desperately puts workpiece temperature downward presses.

Aluminum alloy 7075-T6 texture biased soft, Brinell hardness only is HB 150, but extremely sticks tool. Grinding wheel goes up turns two circles, air pores inside stuffed full silvery white's aluminum chips. Treating soft material, choose equipped structure loose's 46 number silicon carbide grinding wheel, equipped on concentration 5%'s synthetic cutting fluid lubricates, just will not on aluminum material surface drag out 0.1mm deep's rough scratch marks.

Heat treatment brought's deformation amount is a sum must calculated accurate's account. A root long 400mm's SKH51 ejector pin, entering fire furnace before straight, comes out after middle bends folds 0.3mm. Grinding machine master first uses center hole tops against two ends, finds accurate highest point down tool, every time only cuts away 0.005mm, consumes two hours puts 0.3mm's bending amount little by little grinds flat, slightly greedy for fast ejector pin receiving heat warps getting more severe.