Kitamura CNC precision engineering: what the platform actually does

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  How a Kitamura CNC holds tolerance
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  Kitamura CNC precision engineering in the cut: thermal drift, chips and setup
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  Simultaneous 5-axis: what it buys on complex geometry
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  What GreatLight runs, and where the boundaries sit
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  Verification: how you know the number on the drawing was met
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  Matching the machine class to the part

Tool deflection and spindle growth are the two errors that eat a precision budget before the tool ever touches metal. A Kitamura CNC platform attacks both with structure rather than software: heavily ribbed castings, hand-scraped box ways, and a spindle with a short, stiff overhang. The result is a machine that deflects less under the same cutting force, so the finishing pass removes a predictable chip load instead of chasing chatter.

The second lever is thermal. Cast iron grows roughly 11 μm per metre per degree Celsius. On a 400 mm part, a 3 °C shop swing moves the workpiece about 13 μm, which is already past a ±0.005 mm band. Machines in this class compensate by keeping the ballscrew, spindle and column at a stable temperature, and by locating the scale close to the cutting zone so the feedback loop reads what the tool actually sees.

Geometry is the third part. True simultaneous five-axis motion lets the tool stay normal to a curved surface, so a ball nose cutter engages the same part of its radius all the way across a sweep. That keeps effective cutting speed and chip load constant, which is why surface finish on a contoured mould insert improves even when the tolerance band does not change.

None of this removes the need for a stable process. Rigidity on the machine side has to be matched by a sensible setup, a sharp tool, and a fixture that does not move under load. A stiff machine cutting a loose part still produces scrap.

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  Structure firstCast iron mass and box ways cut deflection before compensation is applied.
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  Thermal controlStable spindle and screw temperature protect a ±0.005 mm band across a shift.
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  Tool orientationFive-axis motion keeps chip load constant on contoured surfaces.

In production, most out-of-tolerance parts come from drift, not from the first-off. A spindle warming from 22 °C to 30 °C over the first two hours moves the tool tip in Z. Shops handle this by running a warm-up cycle before the first good part, by holding coolant temperature, and by scheduling the tightest features after the machine has stabilized. If a drawing carries a ±0.005 mm bore, that bore should not be cut at 7 a.m. on a cold machine.

Chip evacuation decides whether the finish survives. Deep pockets in 6061 or 7075 aluminium flood a small cutter with chips, and recutting them doubles the load on the edge. Through-spindle coolant, air blast and a pecking strategy that clears the floor all reduce that risk. In titanium and Inconel the same problem shows up as heat, so the process leans on lower surface speed, higher feed per tooth, and a rigid setup that tolerates the higher cutting force.

Setup is the quiet variable. A vise on a sub-plate repeats to a few microns; a clamped block on parallels may move 20 μm when the clamps are torqued. For parts with a true position callout, we indicate the datum in the fixture, cut the critical faces in one orientation where possible, and record the offset in the setup sheet so the second shift starts from the same numbers.

The practical effect: the machine sets the ceiling, and the process decides how close to that ceiling you actually run. A ±0.005 mm capability on the spec sheet becomes a ±0.005 mm part only when warm-up, coolant and fixturing are all controlled.

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  Warm up firstRun a spindle warm-up cycle before the first tight-tolerance cut of the shift.
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  Clear the chipsThrough-spindle coolant or air blast stops recutting in deep pockets.
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  Lock the setupIndicate the datum and record offsets so the next shift repeats the same numbers.

Simultaneous five-axis motion is not about reaching five sides. It is about keeping the cutter engaged at a controlled angle. On an impeller blade or a turbine vane, a three-axis machine has to tilt the part or accept a changing contact point, which changes the effective radius and leaves witness marks. Five-axis interpolation holds the contact point steady, so the surface comes off in one continuous pass.

The trade is program complexity. A simultaneous toolpath needs a post-processor that respects the machine's rotary limits, plus verification for collisions between the holder and the part. On a compact 500 × 500 × 450 mm envelope, a Ø400 mm rotary table gives room for a turbine disc or a large valve body, but the holder still has to clear the walls. That check happens in CAM, not at the machine.

Where the platform stops paying off is simple prismatic work. A bracket with tapped holes and flat faces runs faster on a three-axis machine with a good fixture, because the five-axis setup and verification time is pure overhead. The rule we use: if the part has no compound angle, no contoured surface and no undercut, three axes are the cheaper route.

Five-axis also shortens the queue for parts that would otherwise need three or four separate setups. Each eliminated setup removes a re-clamping error, and on a part with a 0.02 mm true position between two faces, that error is often the whole budget.

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  Contoured surfacesConstant contact angle keeps chip load and finish uniform across a sweep.
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  Fewer setupsOne five-axis orientation replaces three or four re-clamps.
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  Not for flat partsPrismatic brackets are cheaper on a well-fixtured three-axis machine.

GreatLight operates 127 high-precision CNC machines across three wholly-owned plants and 7,600 m² in Dongguan, plus a factory in Singapore. The five-axis group covers 16 simultaneous machining centers, with a further 12 four-axis mills, 27 three-axis machines and 16 mill-turn centers. Maximum processing size reaches 4,000 mm, with common travels of 750 × 1,150 × 550 mm, 600 × 600 × 600 mm, 500 × 500 × 450 mm and 500 × 310 × 200 mm.

Tolerance capability sits at ±0.005 mm (±0.0002 in), with surface finish down to Ra 0.2–0.8 μm when a part needs it. Standard as-machined finish is Ra 1.6–3.2 μm. Those numbers are achievable, not automatic: they depend on material, feature depth and the fixture, and a deep 3 mm slot in 17-4PH is a different job from a 20 mm face in 6061.

Materials we cut daily include 6061-T6, 7075, 2024 and 6082 aluminium; 303, 304, 316L, 17-4PH and 440C stainless; 1018, 4140, 4340 and tool steel; C36000 brass and beryllium copper; TC4 titanium, Inconel and magnesium. Finishing covers anodizing, electroless nickel, plating, powder coating, black oxide, bead blasting and laser marking.

Where the boundary sits: very deep small-diameter holes, thin walls under 0.5 mm, and parts that need both a mirror finish and a tight tolerance on the same face take longer and cost more. We would rather flag that at the quote stage than discover it on the machine.

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  Capacity127 machines, 16 simultaneous five-axis centers, 4,000 mm maximum size.
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  Tolerance±0.005 mm, with surface finish from Ra 0.2 μm on request.
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  MaterialsAluminium, stainless, steel, copper alloys, titanium, Inconel, plastics.
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  Known limitsSub-0.5 mm walls and deep small holes raise cost and lead time.

A tolerance claim is only as good as the measurement behind it. CMM inspection on a temperature-stabilized part is the baseline for hole position, profile and true position. For bores that carry a fit, an air gauge or bore micrometer gives a faster read on the shop floor. Surface finish gets checked with a profilometer when the drawing names an Ra value.

GreatLight runs raw material verification, in-process monitoring and final inspection, with 100% inspection before shipment. Inspection reports are available on request, and for a first article we can supply the dimensional results against the drawing so your quality team can review the data before the run continues.

The qualification rate across production is 99.99%. That figure describes the process, not a promise about any single part. It reflects in-process checks that catch a drift before a batch is finished, rather than inspecting everything at the end and sorting good from bad.

If your drawing calls out a GD&T scheme, send it with the RFQ. Datum structure changes how we fixture the part, and knowing it at quote time is cheaper than reworking a fixture after the first article.

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  CMM baselinePosition, profile and true position measured on a stabilized part.
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  In-process checksDrift is caught mid-run, not sorted out at the end.
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  Reports on requestFirst article data and dimensional reports ship with the parts.