Cabinet CNC: What You Need to Know

A typical cabinet job starts as a flat sheet: plywood, MDF, particleboard, or solid wood. The router table holds the sheet by vacuum, cuts the outline with a compression bit, then changes tools to drill shelf-pin holes, hinge cups, and dowel bores. Grooves for back panels and drawer bottoms come from the same setup, so every panel in a run shares one coordinate system.

The result is a flat-pack kit. Panels drop into place because the holes were drilled from the same program that cut the edges. That is the core advantage over manual layout: not speed alone, but repeatability across hundreds of panels.

Not every cabinet needs a 5-axis machine. A three-axis router with a boring head handles most rectangular casework. Curved doors, angled corner cabinets, and shaped toe kicks are where rotary axes earn their cost.

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  CuttingOutline, rabbets, and grooves with compression or down-cut bits.
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  BoringShelf pins, hinge cups, dowels, and connector holes.
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  NestingParts arranged on one sheet to reduce waste.
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  LabelingPart numbers printed or stickered for assembly.

Plywood cuts cleanly and holds screws well. Baltic birch and void-free grades are common for exposed cabinet interiors. MDF machines to a smooth edge and takes paint without grain raise, but it is heavy and swells if moisture reaches the core. Particleboard is the cheapest option for painted or laminated carcasses; it needs edge banding because the raw edge crumbles.

Solid wood is different. It moves with humidity, so a CNC-cut solid door can cup or twist after finishing. For solid wood cabinets, leave expansion allowance and avoid rigid joinery that fights the grain.

Some jobs mix materials. A plywood carcass with MDF doors is normal. Tell the shop which faces will be visible, because that decides which side needs a clean cut and which can be nested tighter.

Cabinet work does not need the same tolerance as an aerospace bracket, but hole position does matter. If hinge cup bores drift 0.3 mm between panels, doors sit uneven and the installer spends the day adjusting. A CNC router holds hole position within ±0.1 mm on a good day, and a metal-capable machine can reach ±0.005 mm when the fixture is rigid.

Panel thickness varies more than most people expect. A nominal 18 mm sheet can measure 17.6 mm to 18.4 mm. If your design assumes a fixed thickness, hinges and slides will bind. Machine the hinge bore from the actual measured thickness, not the nominal one.

Edge quality is a separate tolerance. A compression bit gives a clean top and bottom edge. A standard up-cut bit can tear the veneer on the exit side. For exposed plywood edges, specify the bit type in the drawing notes.

Use CNC when you have more than a few identical panels, when hardware holes must line up, or when the cabinet has curves and angles that a table saw cannot repeat. A run of 20 wardrobes with the same shelf-pin pattern is a good fit. A single custom bookcase with hand-fit joints is often faster to build at a bench.

Skip CNC when the design depends on hand-fitted joints, when the material is a one-off slab with unpredictable grain, or when the cabinet will be assembled on site and field-cut anyway. Machining a panel you will trim later is wasted money.

For metal cabinet components, such as stainless steel frames, hinges, and drawer slides, the same shop can often run both wood and metal parts. That is useful when a cabinet has a metal subframe or a machined handle.

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  Good fitRepeated panels, complex hole patterns, curved fronts.
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  Poor fitOne-off hand-fit work, unpredictable reclaimed timber.
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  Mixed buildWood carcass plus machined metal frame or hardware.

Sheet yield is the biggest lever. Nesting software packs parts onto each sheet, and a 5 percent improvement in yield is real money on a large run. Give the shop your panel list with grain direction marked, because grain constraints limit how tightly parts can nest.

Tool changes add time. A program that uses four bits costs more to run than one that uses two. Grouping parts by tool path helps. So does standardizing hinge and shelf-pin patterns across a product line.

Finishing is often quoted separately. Edge banding, paint, and laminate pressing are not router operations, but they affect lead time. If you need a finished cabinet, say so at the quote stage.