CNC 1810: 5 Essential Tips to Boost Accuracy and Cut Production Costs

The cheapest accuracy gain on a CNC 1810 part is removing a setup. Every time the workpiece leaves the fixture and comes back, a new datum appears. A fixture that repeats to 0.02 mm sounds fine on its own. Stack four or five of those across the six faces of a housing and the errors add up in the same direction. You then spend the finishing pass chasing a feature that moved, not a tool that cut wrong.

For parts with features on four or more faces, we run 5-axis simultaneous machining and complete the geometry in one clamping. GreatLight has 16 simultaneous 5-axis machining centers, 12 four-axis mills and 27 three-axis machines, so the machine is matched to the geometry rather than the other way round. A simple bracket does not need 5-axis. A valve body with cross-drilled ports and a conical seat does.

The saving is not only tolerance. One setup removes a queue move, a re-datum, and one inspection pass between operations. On a 200-part order, that is often the difference between shipping in 3–5 days and losing a week to rework. Keep 3-axis for flat plates and prismatic parts; the extra axis costs money when the geometry does not use it.

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  Use 5-axis whenFeatures on 4+ faces, angled ports, or a datum that is hard to re-establish.
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  Keep 3-axis whenPart is prismatic, two or three faces, and the fixture repeats well.
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  Watch forLong tools in deep cavities. Deflection can exceed the setup error you removed.

18/10 bar and plate arrive with internal stress from cold drawing, rolling or forging. The material looks stable until you remove one side of it. Then the balance tips and the part bows, typically 0.03–0.10 mm over a 100 mm length on a thin section. If that movement happens after the finishing pass, the part is scrap. If it happens during roughing, you can still correct it.

The fix is sequencing, not exotic equipment. Rough with 0.3–0.5 mm of stock left, stress-relieve where the drawing calls for it, then finish. For parts where dimensional stability is critical, thermal stabilization is part of the route rather than an optional extra. The cost of one furnace cycle is small next to a batch of finished housings that no longer fit.

Thin walls and long parts move most. A 2 mm wall on a 150 mm deep pocket will deflect under its own clamping load, not just from residual stress. Plan the roughing passes to leave symmetric stock on both sides so the part releases evenly. If only one side is machined before the part is flipped, the bow shows up on the second op.

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  Thin sectionsLeave equal stock both sides and relieve before finishing.
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  Cold-drawn barHigher stress than plate. Expect more movement after roughing.
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  Do not skipRelief on parts with a flatness or parallelism callout.

The 10% nickel in 18/10 gives it ductility and makes it sticky at the cutting edge. A toolpath copied from 304 stainless will produce a built-up edge, smeared finish and short tool life. The symptoms look like a machine problem. They are usually a chip problem: the chip welds to the insert, breaks off, and takes a piece of the edge with it.

For roughing, use sharp positive-rake carbide with a coating suited to stainless, and keep the feed per tooth high enough that the edge cuts rather than rubs. Light feeds in gummy stainless generate heat at the flank and work-harden the surface you are about to finish. Depth of cut should stay above the work-hardened layer left by the previous pass, otherwise the next pass cuts through a harder skin.

Finishing is where the accuracy shows up. A rigid setup with a short tool, a moderate nose radius and a feed that keeps the tool moving gives Ra 0.8–1.6 μm on most 18/10 parts. Where the drawing calls for finer, we plan a separate finishing operation and inspect the surface before it is too late to change the parameters. Deep pockets need a different strategy: reduce the overhang and accept a smaller stepover.

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  RoughingPositive rake, coated carbide, feed high enough to avoid rubbing.
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  FinishingShort tool, moderate nose radius, steady feed, Ra 0.8–1.6 μm typical.
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  AvoidDwelling in the cut. It work-hardens the surface under the tool.

A machined 18/10 part is rarely finished when it leaves the spindle. Deburring, passivation, bead blasting, laser marking and packing are all steps that can be sent out. Each one adds a transport leg, a handling risk and a queue that nobody controls. The handling risk matters most: a 0.01 mm edge nick from a poorly packed box is enough to fail an incoming inspection.

When those steps stay in the same plant, the part moves from machine to finishing cell without a crate and a purchase order in between. GreatLight runs surface finishing in-house, including bead blasting, tumbling, brushing, polishing, laser marking and electroless nickel or zinc plating. Marking character height has a 1.5 mm minimum, which is worth knowing before the drawing is frozen.

The cost argument is straightforward. Fragmented supply chains charge for each setup, each document and each shipment. Consolidating removes the freight legs and the incoming inspection at every handoff. It also shortens the critical path, which is why parts can ship in 3–5 days once production starts.

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  Handling riskEach extra shipment is a chance to damage a finished surface.
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  DocumentationOne supplier means one set of inspection records.
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  Laser markingMinimum character height 1.5 mm. Check the drawing early.

A paper certificate that arrives with a shipment tells you what the part was, not what it is now. If a tool wears through a batch and the first measurement happens at final inspection, you find out after 200 parts are finished. In-process measurement catches the drift while there is still stock to correct it.

For 18/10 parts with tight callouts, we check the raw material before cutting, monitor dimensions during the run, and inspect 100% before shipment. Reports are available on request. The tolerance we hold is ±0.005 mm (±0.0002 in) where the geometry and setup allow it. On long parts or thin walls, we will tell you if the drawing is asking for something the material will not hold after it relaxes.

This is also a DFM question. If a feature has no datum that can be reached in the same setup, no amount of inspection will make it repeatable. We flag that during quotation, within 12 hours, before the toolpath is written. It is cheaper to move a datum on a drawing than to scrap a finished lot.

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  Raw materialChecked before the first cut, including grade and condition.
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  In-processDimensions monitored so tool wear is corrected in the run.
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  Final100% inspection before shipment, reports on request.