LJ-855 Vertical Machining Center | Travel Capacity, Mold Plate Work, and Precision Output

LJ-855 vertical machining center travel approximately 800×550×550mm, suitable for mold plate processing; spindle 12000rpm, positioning accuracy ±0.005mm.

Adopting three-axis linkage rough and finish step-by-step, tool compensation and cooling combined control, improving surface quality and stability.

Travel Capacity

Coordinate Axis Parameters

The LJ-855 machine worktable length is calibrated at 1000mm, width 500mm. Castings select FC300 high-grade resin sand cast iron. X-axis 800mm effective movement travel, matching 35mm width ball linear guide rails. The distance from the spindle center to the column guide rail surface is set at 560mm, ensuring torque support during processing.

This machine load capacity reaches 600kg. The interior of the base is densely distributed with 12 reinforcing ribs, casting wall thickness maintained at 25mm. When the workpiece weight approaches the upper limit and moves at the edge of the worktable, the table surface sinking amount is controlled within 0.01mm. The Y-axis 500mm travel corresponds to the full width of the worktable, allowing the processing tool to cover every edge of the part.

· X-axis ball screw diameter reaches 40mm, lead 12mm.

· Three-axis positioning accuracy is calibrated at 0.005mm.

· Repeat positioning accuracy is maintained at 0.003mm.

· Rapid move speed is set at 36m/min.

· Screw support end is configured with 25-60 specification combined bearings.

Z-axis 500mm travel provides a height difference from nose end to table surface of 150mm to 650mm. After installing a 150mm height vise, it still possesses 350mm of operational clearance. The BT40 spindle motor temperature rise remains at room temperature +15 degrees Celsius after 4 hours of continuous operation. The vibration value at the maximum spindle speed of 10000rpm is lower than 0.8mm/s.

The 24-tool disk-type manipulator tool magazine requires only 1.8 seconds for a single tool change cycle. The tool magazine tool change position coordinate is fixed at 118.5mm below the Z-axis mechanical origin. The spindle box constant temperature oil cooling system flow is 20 liters per minute. This layout allows the operator to still have sufficient tool retraction and tool change space when handling 400mm high deep cavity molds.

· Motor feedback pulse is 1,000,000 counts per revolution.

· Laser interferometer compensation step distance is set at 10mm.

· Control system scanning cycle is shortened to 1ms.

· Foundation bolt specification adopts M24 standard.

· Cutting fluid tank capacity reaches 200L.

· Base rear flush pressure is constant at 2.5bar.

The electrical cabinet is equipped with a 1.5HP heat exchanger. The X-axis motor is directly connected to the screw through a high-rigidity coupling, locking torque 45N.m. Under the Y-axis saddle, 4 sets of Teflon-pasted guide rail surfaces are arranged, friction coefficient stabilized at 0.04. This makes the machine movement have no crawling lag feeling under a feed unit of 0.001mm.

The high-brightness LED light installed on the side of the spindle box reaches 500lux illuminance. The fully enclosed protection door opening width is 850mm. The operator's manual loading and unloading operation radius is controlled within a comfortable range of 600mm. The hydraulic buffers configured at both ends of the X/Y axes have an impact kinetic energy absorption limit of 35J.

· Maximum tool diameter limited to 78mm (full tool state).

· Maximum tool length limited to 300mm.

· Maximum tool weight limited to 7kg.

· Spindle motor peak power output reaches 11kW.

· Lubricating oil pump displacement is 3-6ml oil injection every 15 minutes.

System soft limit sensing delay is controlled within 8ms. The base chip groove slope is set at 30 degrees, matching a high-pressure water pump with 30L per minute flow, which can quickly take away 1.2kg of aluminum chips per minute.

Machine static rigidity measured value is 45N/micron. When processing No. 45 steel with 3mm cutting depth and 1500mm/min feed, the machine body vibration amplitude is not higher than 5 microns. All three-axis drive bearings adopt grease lubrication sealing, replacement cycle marked as 5000 operation hours. Installation level accuracy needs to be adjusted to within 0.02mm/1000mm.

Z-Axis Net Space Calculation

The LJ-855 machining center Z-axis total travel is calibrated at 500mm, the distance from the spindle nose end to the worktable surface swings between 150mm and 650mm. This 500mm vertical span, after installing the BT40 spindle, needs to subtract the 65mm to 100mm occupied length of the tool holder itself. For ordinary readers, the height of the workpiece that can actually be stuffed in is not as large as the physical parameters displayed.

Assuming the workpiece height is 200mm, installed on a precision flat-nose vise of 150mm height, at this time the net space from the top of the workpiece to the spindle nose end is only 300mm left. If using an extension shank milling cutter with a total length of 250mm, the tool lift height during tool change must be accurately calculated.

The Z-axis screw adopts a C3 grade ball screw with 40mm diameter and 10mm lead. To offset the approximately 450kg self-weight of the spindle box, the machine interior is equipped with double nitrogen balance cylinders or a counterweight structure, ensuring Z-axis start-stop impact current fluctuation is lower than 15% under 36m/min rapid move speed. The servo motor directly drives the screw through a coupling with 55N.m locking torque.

Column guide rail span is set at 380mm, the six-slider layout increases the spindle rigidity at all travel positions. When the spindle box is at the highest point, the soft limit reserved distance of the induction switch at the top of the column is 12mm. In deep hole drilling operations, if the drill bit length exceeds 300mm, the program jump point needs to be set above Z50 of the G54 coordinate system to prevent interference when the tool change arm grabs the tool.

· Tool magazine manipulator tool grabbing position is fixed at machine coordinate Z-118.5mm.

· Response time for Z-axis lifting to the reference point during tool change is 0.6 seconds.

· Minimum feed resolution during probe automatic tool setting is 0.001mm.

· Motor brake sliding amount at the moment of power failure is controlled within 0.05mm.

The spindle constant temperature oil cooler locks the circulating oil temperature at room temperature -2 degrees Celsius, preventing Z-axis spindle box thermal expansion from producing displacement. After continuous cutting for 5 hours, through infrared detection, the spindle bearing seat temperature rise is only 12 degrees Celsius. This thermal stability ensures that when the Z-axis repeats positioning, it can death-grip the 0.003mm tolerance red line.

Processing aluminum alloy plates with 300mm thickness, if adopting fly cutter disc face milling, the cutting edge distance to the worktable surface height is 450mm. At this time, the Z-axis slider is still located in the central rigidity zone of the column guide rail, the processing amplitude is measured to be lower than 4 microns. The Z-axis load rate displayed in real-time on the operation panel, during 30mm diameter drilling processing, is constant between 45% and 55%.

· Maximum tool change length limit: 300mm.

· Maximum tool change weight limit: 7kg.

· Tool magazine adjacent tool position maximum diameter: 78mm.

· Tool magazine isolated tool position maximum diameter: 120mm.

· Spindle pull force strength: 800kgf.

The Z-axis protection cover adopts a stainless steel armor structure, each section folding thickness is 25mm, which does not occupy effective travel after full compression. The base oil outlet pressure is maintained at 3bar, matching the Z-axis anti-water spray nozzle, which can clean away 1.5kg of iron chip accumulation per minute. The 2000 pulse encoder inside the electrical cabinet monitors every 0.01mm displacement change of the screw in real-time.

Since the Z-axis carries the entire cutting main force, the support seat selects NSK 25-60 series combined bearings, installed back-to-back to absorb axial impact. When processing mold steel with hardness above HRC45, the feed system processes 1000 sets of data per second, dynamically compensating for the thermal elongation of the screw, the compensation value is usually between 0.008mm and 0.015mm.

In daily maintenance, the Z-axis automatic oil injection pump works once every 15 minutes, oil injection pressure 1.2MPa. This micro-lubrication ensures the oil film thickness between the slider and the guide rail is maintained at about 0.02mm. This LJ-855, piled up with such details, is not only a collection of three-dimensional coordinates but also a precision control of 500mm vertical space.

Travel Load

The LJ-855 machine worktable calibrated load capacity is 600kg, this value is established on the basis of the FC300 resin sand cast iron base. 12 reinforcing rib plates are arranged inside the base, single rib plate thickness reaches 25mm. This structure can suppress the static deformation of the table center area to within 0.008mm when placing heavy mold blanks above 400kg.

When the workpiece performs full-speed movement within the 800mm X-axis travel, the load pressure distribution of the machine base will shift. 35mm specification precision grade ball guide rails bear the main vertical load, slider span is set at 420mm. This large span design ensures that when the worktable runs to the left and right limit positions, the sinking amount of the table edge will not exceed 0.01mm.

· X-axis and Y-axis ball screw diameters both select 40mm specification.

· Screw lead is 12mm, matching a servo motor with 12N.m torque.

· Screw support end adopts 25-60 series high-rigidity combined bearings.

· Rapid move speed can still maintain 36m/min under 400kg full load state.

· Motor feedback pulse generates 1,000,000 count units per revolution.

During actual processing of No. 45 steel, cutting depth is set at 3mm, feed speed 1500mm/min. The amplitude shown by the machine body at this time is measured to be no higher than 5 microns.

The Y-axis 500mm travel load is jointly supported by 4 sets of Teflon-pasted guide rail surfaces, the friction coefficient of this material is stable at around 0.04. When performing 0.001mm micro-feed, the low friction characteristics effectively prevent crawling phenomena. Machine static rigidity measured value is 45N/micron, this ensures that under heavy-duty cutting, the tool tip trajectory deviation from the set path remains at an extremely low level.

Spindle motor power continuous output 7.5kW, peak can reach 11kW in a short time. When performing heavy cutting operations with a 50mm diameter disc milling cutter, the axial cutting force borne by the spindle box is converted into torque load by the Z-axis 40mm diameter screw. The Z-axis interior is equipped with double nitrogen balance cylinders to offset the 450kg self-weight of the spindle box, keeping start-stop current fluctuation range within 15%.

· Bearing model selects NSK 7014 series angular contact ball bearings.

· Vibration value at maximum spindle speed 10000rpm is lower than 0.8mm/s.

· Automatic oil injection pump pumps 3-6ml of grease to each lubrication point every 15 minutes.

· Laser interferometer positioning compensation step for full travel is 10mm.

· Control system scanning cycle for motion trajectory is shortened to 1ms.

Aiming at 300mm thick aluminum alloy plate processing, the chip volume generated per minute can reach 1.2kg. The base is set with a 30-degree slope chip groove, matching a 2.5bar pressure rear flush system, which can quickly take away waste chips.

Full travel positioning accuracy executes the 0.005mm standard, repeat positioning accuracy then stabilizes at 0.003mm. This accuracy index is corrected by relying on the screw thermal expansion compensation function within a range of 5 degrees Celsius environmental temperature fluctuation.

The BT40 spindle pull force strength reaches 800kgf, ensuring the tool will not produce radial movement under heavy load cutting. The disk-type manipulator tool magazine accommodates 24 tools, single shank tool maximum weight limit is 7kg. During the full-load tool change process, the Z-axis runs from the processing position to the tool change position 118.5mm below the mechanical origin, taking only 1.8 seconds.

· Machine foundation bolt specification selects M24, a total of 6 support points are set.

· Installation level accuracy adjustment requirement is within 0.02mm/1000mm.

· Lubricating oil tank capacity is 2L, alarms triggered when liquid level is lower than 20%.

· Electrical cabinet heat exchanger power is 1.5HP.

· Z-axis soft limit sensing delay response time is lower than 8ms.

If the adjacent tool positions of the tool magazine are full, the maximum tool diameter is limited to 78mm. If adopting separated tool loading, the maximum diameter can be expanded to 120mm, at which time the load balance of the tool change arm needs to be re-verified.

The spindle bearing seat is equipped with a constant temperature oil cooling circulation system, cooling liquid flow maintained at 20L per minute. After running for 4 hours, the maximum temperature rise in the spindle area is limited to room temperature plus 15 degrees Celsius. This temperature control measure prevents accuracy exceeding tolerance at the end of travel due to thermal deformation. The machine's fully enclosed protection door opening width is 850mm, reserving sufficient operation space for hoisting 600kg upper limit workpieces.

The base chip groove, matching a high-pressure pump with 30L per minute flow, ensures iron chips will not accumulate on the inside of the protection cover. The drive bearing grease lubrication sealing design supports an operation cycle as long as 5000 hours. The hydraulic buffers installed at both ends of the X-axis can absorb 35J of kinetic energy when accidental impact occurs. The machine's overall weight reaches around 5 tons, the heavy machine body absorbed the resonance generated by high-frequency cutting.

· Worktable T-slot number is 5, slot width 18mm.

· Spindle taper hole radial jump measurement is 0.002mm.

· Cutting fluid tank total volume calibration is 200L.

· LED work light illuminance reaches 500lux at table center position.

· Maximum tool extension length suggestion is controlled within 300mm.

Under a feed unit of 0.001mm, the encoder feedback generates 1 million pulses per revolution. This fine pulse resolution matches high-rigidity couplings, making the motor locking torque reach 45N.m. This data performance ensures that LJ-855 can still maintain a stable movement trajectory and precision output when facing travel load changes on complex mold surfaces.

Mold Plate Work

Space & Bearing

LJ-855 machine total weight reaches 5500kg, base adopts large-span four-guide-rail layout, HT300 gray cast iron material passed through twice artificial aging. Reinforcing ribs are arranged inside the machine body, offsetting high-frequency vibration under 10000rpm speed. Worktable 1000mm x 500mm specification, table surface thickness 150mm.

This worktable load upper limit is 600kg, sufficient to load P20 steel mold blanks of 600mm x 400mm specification. X/Y axis guide rail width 35mm, Z-axis guide rail width increased to 45mm, supporting the up and down movement of the BT40 spindle head. Guide rail pair installation surfaces undergo high-precision grinding.

· BT40-10000rpm direct-coupled spindle speed

· 11/15kW servo motor rated output power

· Spindle end jump measured value ≤0.002mm

· Spindle oil cooling circulation pump flow 15L per minute

· Ceramic ball bearing configuration, reducing high-speed friction heat

· 24-station disk-type tool magazine, tool-to-tool exchange time 2.2s

Three axes select C3 grade precision ball screws, diameter 40mm. Screw support end adopts pre-stretching process, offsetting thermal expansion volume generated by continuous processing. Within 300mm travel, positioning accuracy is stable at around 0.005mm. Repeat positioning accuracy maintained within 0.003mm range.

Servo motor and screw are 1:1 directly connected through a high-rigidity coupling. Omitting intermediate transmission links, improving signal response speed. When performing 50mm fly cutter disc roughing, cutting depth taken as 2.0mm, the machine spindle load meter displays 65%.

Aiming at P20 pre-hardened steel (HRC 28-32), cutting speed Vc is set at 150 m/min. Feed per tooth fz takes 0.12mm. Lateral cutting width Ae is 70% of tool diameter.

· S136 stainless steel template processing roughness Ra 0.6um

· 200mm depth inner hole verticality deviation 0.008mm

· Guide pillar hole H7 tolerance pass rate reaches 99%

· Y-axis full travel positioning error 0.006mm

· Spindle 8-hour continuous temperature rise ≤2℃

· Cutting fluid tank volume 200L, pump pressure 4bar

LJ-855 total travel error within 800mm travel is controlled at 0.01mm. When finish milling six sides, matching with magnetic chucks, parallelism can be controlled within 0.01mm/100mm range. Spindle oil cooler monitors real-time temperature once every 30 seconds.

Sealing groove processing usually uses 3mm-6mm end mills. When spindle is at 8000rpm, machine amplitude is lower than 1um. Under high-frequency reciprocating movement, the low friction coefficient of three-axis linear rails ensures that size overcutting does not occur at corners.

Cooling nozzles are distributed around the spindle, providing 360-degree coverage. Flushing pressure is sufficient to take away chips in 15mm deep grooves. Oil-water separation device processes 5L waste oil per hour, maintaining cooling liquid concentration at around 8%-10%.

· X/Y/Z axis travel: 800/500/550mm

· Spindle nose end to worktable distance: 150-700mm

· T-slot specification: 18mm x 100mm x 5 slots

· Air source pressure requirement: 6-8kg/cm²

· Total power consumption: 25kVA

· Machine floor area: 2800mm x 2300mm

Guide pillar hole processing adopts U-drill for hole starting, followed by fine boring. Torque provided by LJ-855 supports 40mm drill bit driving straight into S50C material. During boring, Z-axis downward rigidity ensures no ripple residue on the hole wall. Fine boring tolerance zone controlled within 0.02mm width.

Automatic lubrication system gives oil once every 15 minutes. Guide rail surface covered with a 0.02mm thick oil film. This protection mechanism prevents dry friction caused by frequent movement of heavy-load templates. Screw bearing seat and machine body casting are integrated molding, enhancing transmission rigidity.

Electrical cabinet installed with a heat exchanger. Under workshop environment 35℃ state, cabinet internal temperature maintained at 28℃. CNC system processing speed reaches 2000 block look-ahead, adapting to complex surface template processing. Grating scale (optional) can further pull up positioning accuracy.

Operator performs micro-adjustment through handwheel, minimum feed amount 0.001mm. This accuracy satisfies the tool junction requirements of precision electronic molds. Since the column adopts an A-shaped structure, Z-axis back-tilting deformation during heavy cutting is limited to an extremely small value.

Factory inspection report shows this machine model geometric accuracy conforms to JIS B6330 standard. Static accuracy detection includes spindle axial movement 0.003mm. Dynamic circle test indicates out-of-roundness under XY linkage is controlled within 0.008mm.

Rigidity & Cutting

LJ-855 machine self-weight reaches 5500kg, base adopts HT300 high-strength gray cast iron, through twice artificial aging treatment. 45mm wall thickness matching internal 18 sets of vertically and horizontally distributed reinforcing ribs, controls machine center of gravity within 300mm height from base center.

Bed width 1200mm, providing large-span four-guide-rail support surface. When carrying 600kg mold blank for X-axis 800mm full travel movement, worktable edge sinking amount is controlled within 0.01mm. This mechanical structure offsets the reaction force generated by large cutting forces.

· 5500kg whole machine physical weight

· HT300 gray cast iron machine body material

· 45mm casting wall thickness specification

· 18 sets internal reinforcing rib layout

· 1200mm ultra-wide base span

· 600kg maximum worktable load

Experimental data records show that when 50mm fly cutter disc performs P20 steel rough processing, spindle box amplitude displacement remains within 0.005mm range.

BT40 direct-coupled spindle rated power 11/15kW, speed reaches 10000rpm. Spindle head configured with four sets of P4 grade high-precision bearings, support rigidity sufficient to handle lateral impact of 2.0mm cutting depth. Within 1.5 seconds can be pulled up from static to highest speed.

95Nm rated torque transmitted through coupling, power transmission loss lower than 3%. When performing H13 mold steel (hardness HRC 48-52) roughing, spindle load meter maintained at around 65%. This output stability protected tool tip from producing edge chipping due to force fluctuations.

· 11/15kW spindle drive power

· 95Nm rated output torque

· 10000rpm highest design speed

· P4 grade imported high-precision bearings

· 1.5s spindle start-stop response time

· Within 3% power transmission loss

Aiming at H13 material, under cutting speed 120m/min condition, spindle temperature rise 8-hour continuous monitoring value does not exceed 2 degrees Celsius.

Three axes select 35mm and 45mm specification roller linear rails, contact area more than 30% larger than traditional ball rails. Z-axis slide plate travel 550mm, column width increased by 100mm compared to same-level machine models.

C3 grade ball screw diameter 40mm, both end support bearings undergo 30% pre-stretching treatment. This process offsets 0.015mm elongation generated by screw friction heat. Three-axis rapid displacement speed X/Y 36m/min, Z-axis 24m/min.

· 35/45mm roller linear rail specification

· 30% increase guide rail contact area

· C3 grade ball screw accuracy

· 40mm screw nominal diameter

· 36m/min three-axis rapid speed

· 30% screw pre-stretching ratio

Performing laser interferometer detection within 800mm travel, three-axis positioning accuracy deviation stabilized in 0.005mm physical interval.

In cutting parameter setting, when processing S50C medium carbon steel template, Vc set at 180m/min. Feed per tooth fz takes 0.15mm. Matching 4-flute coated end mill, metal removal rate (MRR) per minute can reach 150 cubic centimeters. Cutting fluid pump pressure 4bar ensures chips are flushed away from processing zone.

Aiming at precision parts such as sealing grooves, vibration value when spindle is at 8000rpm is lower than 1.0um. Low friction coefficient of three-axis linear rails eliminated quadrant error at corners. When performing side milling of 500mm length, size deviation at both ends controlled within 0.007mm range.

· 180m/min cutting linear speed setting

· 0.15mm feed per tooth value

· 150cm³/min metal removal efficiency

· 4bar cooling liquid pump output pressure

· 1.0um high-speed operation vibration value

· 0.007mm side milling size deviation

24-station disk-type tool magazine tool-to-tool exchange time only 1.8 seconds, saved 15% auxiliary time in large-scale multi-hole processing.

Machine foundation distributed on 6 support points, evenly dispersing 5 tons of gravity to concrete ground. Spindle oil cooling system cycles 15L oil liquid per minute, discharging heat to outside through heat exchanger. This environment temperature control mechanism lets machine maintain 0.01mm processing accuracy all day.

Automatic lubrication system operates once every 15 minutes, pressure constant at 2.0MPa. Guide rail surface always covered with a layer of 0.02mm thickness lubricating oil film. This protection measure prevented dry friction loss caused by frequent reciprocating movement of heavy-load templates.

· 6 machine support foundation points

· 15L/min oil cooling system flow

· 0.01mm all-day accuracy fluctuation value

· 15min automatic lubrication interval time

· 2.0MPa lubrication pump constant pressure

· 0.02mm dynamic oil film thickness

Measured data shows that when processing Cr12MoV material template, accumulated size shift of machine running continuously for 12 hours is less than 0.008mm.

Electrical cabinet configured with 500W power heat exchanger, internal temperature always maintained at around 28 degrees Celsius. CNC system 2000 block look-ahead function calculates path in advance, avoiding overcutting during high-speed cutting. Operation handwheel 0.001mm minimum resolution satisfied tool junction micro-adjustment requirements.

Machine full-protection sheet metal prevented iron chips from eroding screws, chip groove slope 45 degrees. Cutting fluid tank capacity 240L, equipped with oil-water separator processing 5L floating oil per hour. This design let cooling liquid usage life extend for more than 3 months.

· 500W electrical cabinet heat exchange power

· 28 degrees Celsius cabinet constant temperature environment

· 2000 block system program look-ahead

· 0.001mm handwheel minimum multiplier

· 45 degrees bed large slope chip removal

· 240L large capacity cutting fluid tank

Aiming at HRC 60 hardness quenched template, LJ-855 matches CBN tools for finish processing. Back cut amount Ap set at 0.02mm, surface roughness measured to reach Ra 0.4um. At this time Z-axis downward rigidity ensured processing surface has no visible tool marks.

Distance range from spindle nose end to worktable is between 150mm and 700mm, adapting to mold bases of different thicknesses. 18mm specification T-slots undergo high-frequency quenching, hardness reaches HRC 45. Since column adopts A-shaped structure, Z-axis back-tilting amount during heavy cutting limited to within 0.005mm.

High-Precision Hole Positions

LJ-855 carries C3 grade grinding screw, diameter 40mm, pitch 12mm. Servo system matching 24-bit absolute encoder, pulse resolution reaches 0.0001mm. When processing 600mm x 400mm templates, distance error between hole positions controlled within 0.008mm.

Three-axis guide rail support surfaces undergo precision scraping, contact points reach 25 points per square inch. Manual craftsmanship ensures worktable stability during frequent start-stops. When processing 20mm diameter guide pillar holes, X/Y axis linkage out-of-roundness measured as 0.005mm.

· 40mm diameter C3 grade double-nut screw

· 24-bit absolute servo encoder signal

· 0.008mm full travel hole position interval deviation

· 25 points/square inch guide rail scraping accuracy

· 0.005mm circular interpolation dynamic out-of-roundness

· 1.0um spindle dynamic balance G2.5 grade

Measured data record: In process of continuously processing 150 6mm diameter ejector pin holes, hole mouth position consistency deviation remains within 0.004mm range.

Aiming at fine boring process with H7 tolerance requirements, BT40 spindle end jump controlled within 0.002mm physical upper limit. Boring tool shank and spindle taper hole contact rate exceeds 90%. When processing S50C material template, boring roughness stable at Ra 0.8um.

Both screw ends applied with 12000N pre-stretching force, offsetting impact generated by 36 meters per minute high-speed displacement. Even if workshop environment reaches 32 degrees Celsius, Z-axis 550mm travel repeat positioning accuracy still maintains at 0.003mm.

Guide pillar hole verticality determined by Z-axis guide rail and worktable surface geometric accuracy. LJ-855 column adopts A-shaped large-span design, side wall thickness 50mm. Hole axis line verticality deviation measured 0.007mm within 200mm depth, eliminated jam hidden danger during mold assembly.

· 12000N screw end physical pre-stretching

· 0.003mm Z-axis repeat positioning accuracy

· 50mm thick-wall A-shaped casting column

· 0.007mm/200mm hole position verticality deviation

· 36m/min three-axis rapid feed speed

· 25Nm Z-axis servo brake torque

Spindle internal oil cooling circulation flow set at 15 liters per minute. Cooler real-time adjusts according to spindle bearing temperature, temperature difference fluctuation within 1 degree Celsius. Constant temperature environment eliminated 0.01mm axial elongation of spindle nose end due to temperature rise.

When processing deep holes exceeding 5 times diameter, feed system has no crawling characteristics. Guide rail lubricating oil pump pressure 2.0MPa, forced oil injection every 12 minutes. 0.02mm oil film thickness reduced friction torque during micro-feed.

During boring processing, spindle oriented stop accuracy reaches 0.05 degrees. Data index ensured tool tip position consistency each time boring tool retracts. Matching system back-lash compensation function, X/Y axis reversal error compressed to 0.002mm.

Matrix hole system distributed on templates, realizes path smoothing relying on 2000 block program look-ahead function. During movement between holes, acceleration/deceleration time constant set at 15 milliseconds. Response speed matching 4.5kW Z-axis drive motor, shortened non-cutting time consumption.

· 0.05 degree spindle oriented stop accuracy

· 0.002mm quadrant reversal gap error

· 2000 block CNC instruction look-ahead depth

· 15ms feed acceleration/deceleration response time

· 4.5kW Z-axis high-power servo motor

· 18mm width T-slot parallelism 0.01mm

Automatic tool changer adopts disk-type structure, tool change time 1.8 seconds. Tool holder cleaning system sprays 6kg pressure compressed air at tool change moment. Air blowing action excluded micro iron chips inside taper hole, maintained radial jump accuracy during boring.

Worktable surface flatness measured 0.012mm within 1000mm x 500mm range. Fit between template bottom and table surface is extremely high. Matching handwheel 0.001mm micro-feed, operator can complete second hole position alignment within 30 seconds.

Heat exchanger power inside machine electrical cabinet 500W. Stable circuit environment reduced servo encoder signal fluctuation. In 24-hour continuous operation test, 400 holes processed showed no defects exceeding 0.015mm tolerance range.

· 1.8s ATC disk-type tool magazine tool change

· 6kg pressure spindle taper hole air spray cleaning

· 0.012mm full table geometric flatness

· 0.001mm electronic handwheel minimum division

· 500W electrical cabinet heat exchange circulation power

· 24h continuous processing accumulated drift less than 0.01mm

Aiming at S136 mirror steel templates, fit gap after hole system processing can be controlled between 0.005mm to 0.01mm. Fit accuracy reduced mold later stage mold-fitting workload. Guide rail oil circulation recovery system processes 3 liters waste oil per hour, maintaining cooling liquid cleanliness.

Each machine through Renishaw laser interferometer detection before factory delivery. Bi-directional positioning accuracy dispersion index conforms to ISO 230-2 standard. Compensation data displayed on operation screen accurate to 0.0001mm, ensuring physical output quality of every precision hole position.

Precision Output

Accuracy Control

LJ-855 selected HT300 gray cast iron in frame manufacturing, tensile strength of this material measured to reach 310MPa. Machine base width designed as 1400mm, self-weight reaches 6000kg, center of gravity pressed down at 350mm height from ground. This counterweight ratio lets machine be very stable during high-speed cutting, even if spindle turns to 10000 rotations per minute, vibration amplitude at bed edge is less than 0.002mm.

Spindle adopts BT40 specification, interior supported by four rows of P4 grade precision bearings. Through measurement, spindle front end jump error controlled within 0.002mm, axial offset during rotation only 0.003mm. This stability directly determines surface delicacy of processed parts, when cutting steel pieces, surface roughness can reach Ra 0.45um.

· Spindle dynamic balance grade: G0.4 grade, vibration speed lower than 0.5mm/s during high-speed rotation

· Taper hole contact rate: Using red lead powder inspection, contact area exceeds 85%

· Constant temperature control: Equipped with 1500W power oil cooler, limiting spindle temperature rise to within 12 degrees Celsius of room temperature

· Torque performance: Continuous processing torque 70N.m, instantaneous burst power can reach 105N.m

To prevent bearing heat deformation, ceramic spheres are used inside, thermal expansion rate of this material is about 30% lower than steel balls. Matching oil circuit circulation system, effectively avoided processing depth exceeding tolerance due to spindle thermal elongation, ensuring size consistency from first piece to hundredth piece of product.

Transmission part uses 40mm diameter C3 grade precision ball screw. Screw applied with 3500N pre-stretching force during installation, which can offset physical elongation caused by friction temperature rise. Three-axis positioning accuracy measured as 0.005mm, repeat positioning error only 0.003mm, deviation of machine returning to same position less than one-twentieth of a hair strand.

· Screw error: Accumulated lead error per 300mm travel lower than 0.008mm

· Guide rail specification: 35mm heavy-load linear rail, single slider load capacity reaches 55kN

· Displacement speed: X/Y/Z three-axis movement speed reaches 36 meters per minute

· Response time: Only 0.15 seconds required from static acceleration to highest speed

· Tool change efficiency: 24-tool arm-type tool magazine, tool-to-tool exchange only needs 1.8 seconds

CNC system possesses 200 block program look-ahead function, data processing speed reaches 1000 characters per second. When processing complex mold surfaces, system can calculate path in advance, eliminated motor pause at micro-line segment junctions. Even if environment temperature changes from 18 degrees Celsius in morning to 30 degrees Celsius in afternoon, built-in thermal compensation algorithm will correct displacement deviation every 10 milliseconds.

During actual processing of 800mm by 500mm mold steel plate, flatness error of whole plate controlled within 0.012mm. Distance tolerance between hole and hole remains around 0.007mm within 200mm range. This high precision reduced later manual polishing and finishing workload.

· Verticality deviation: Error less than 0.015mm within 550mm full travel

· Roundness detection: Using ballbar test, roundness error within 300mm radius is 0.008mm

· Feed acceleration: 0.8G, reduced path deviation at corners

· Residual fluctuation: After clearing roots with 2mm ball cutter, allowance error controlled at 0.01mm

· Table surface parallelism: Rise and fall during worktable sliding less than 0.01mm

Spindle motor maintains constant power output between 1500 to 8000 rotations, which is very beneficial for deep cavity processing. Matching tool wear automatic correction function, depth change amount after replacing new tool compressed to 0.005mm level. High-pressure large-flow cooling water aimed at chip point through annular nozzle, matching 15-degree slope chip groove, preventing hot chips from accumulating inside machine and causing local thermal expansion.

Spindle Cutting Performance

LJ-855 spindle system selects BT40 direct-coupled structure, rated speed reaches 12000 rotations. Spindle interior equipped with Japan NSK or same grade P4 precision bearings, adopting five-bearing arrangement layout of front three rear two. This high-rigidity support structure, when installing 50mm diameter disc milling cutter for large-multiplier lateral cutting, spindle front end deflection offset measured as remaining within 0.004mm.

In process of processing S136 mirror mold steel, cutting speed set as 220m/min, feed per tooth amount 0.15mm. Under spindle 8500 rotation condition, processed side wall finish Ra measured to reach 0.32um. Even facing rough processing of 30mm depth cavity, single cut depth reaching 5mm, spindle load meter pointer still stably jumps around 65%.

Spindle box outer wall surrounded by spiral cooling oil passage with total length 8.5 meters, matching 1.5kW power constant temperature refrigerator. Cooling oil pump circulation flow 12 liters per minute, temperature difference between inlet oil and return oil accurately controlled within 1.5 degrees Celsius. After high-load operation for 12 hours, spindle taper hole radial jump increment locked below 0.002mm, avoided workpiece surface appearance of fracture marks caused by thermal elongation.

Spindle dynamic balance grade measured as G0.4 grade, under 10000 rotation condition, micro-displacement caused by centrifugal force limited within 0.1um. Machine's own vibration sensor monitors data every millisecond, when cutting edge vibration exceeds 0.8mm/s due to wear, system will automatically adjust feed speed.

Using diameter 25mm contour milling cutter treating P20 steel pieces, when single side allowance 0.3mm, cutting noise remains below 75 decibels. This crisp sound originates from scientific distribution of bearing pre-load, avoiding high-frequency whistling. Since spindle and tool holder adopt BT40 standard and taper surface contact rate higher than 85%, effective contact area reached 38.5 square centimeters, greatly improved torque transmission efficiency.

· Spindle motor output: 7.5kW rated power, 11kW peak power (continuous 30 minutes)

· Taper hole self-cleaning air pressure: 0.6MPa, air flow at tool change moment sufficient to blow clean 0.05mm debris

· Spindle axial rigidity: Under 1000N force, axial displacement deformation less than 1um

· Ceramic ball bearing life: Wear resistance cycle improved by more than 2 times compared to ordinary steel balls

· Tool change positioning angle: 0.1 degree pulse control, supporting various side milling heads and angle heads rapid mounting

Treating moving mold core with depth up to 400mm, long extension milling cutter driven by spindle goes deep into cavity bottom. Spindle swing amount even if measured at end of extension rod, is only 0.015mm. This low-jump performance ensured cavity side verticality error maintained within 0.012mm within 500mm depth, greatly reduced tedious manual polishing time on mold mating surfaces.

24-hour non-stop limit test data indicates, spindle running under 80% power load, temperature rise fluctuation always jumps within plus or minus 1.2 degrees Celsius. KLUBER high-speed grease filled inside under fully enclosed environment, working life nominally exceeds 15000 hours. This high durability when facing high-dust electrode processing or high-corrosive cooling liquid spray, maintains protection level at IP65 standard through multi-layer air curtain sealing ring.

· Spindle start time: Only 1.5 seconds from 0 to 10000 rotations

· Oriented stop accuracy: Spindle stop angle error within plus or minus 0.05 degrees

· Disc milling cutter maximum load: Spindle support structure can bear single tool weight up to 8kg

· Vibration suppression: Built-in damping ring design, filtering 80% of high-frequency resonance above 2000Hz

· Lubrication monitoring: Pressure sensor real-time monitors lubrication oil circuit, triggers alarm within 0.1s of under-pressure

In process of continuous drilling with 20mm diameter twist drill bit, spindle output torque constant, hole wall finish performance excellent. Spindle taper hole jump controlled within 0.0015mm, even when using extended U-drill for 10 times diameter depth processing, hole diameter deviation also controlled within 0.02mm.

Cooling liquid through annular nozzle at spindle front end, directly hits tool edge with 25 liters per minute displacement. This cooling intensity can quickly take away 500 degrees Celsius high temperature generated by cutting edge, preventing tool edge chipping due to thermal fatigue. Chip groove matching 15-degree slope design, let hot chips slide into chip conveyor within 2 seconds, preventing machine bed from producing local temperature difference.

Spindle motor power curve shows, within common interval of 1500 to 8000 rotations, output always maintains at constant power platform. This characteristic lets LJ-855 maintain constant cutting resistance when performing large area bottom clearing processing. Under metal cutting removal amount 10 kg per hour, spindle running current fluctuation less than 5%, this stability is physical guarantee of outputting high quality mold plates.