Chicago Wood CNC Processing Service for Engineered Wood Parts

Not every wood behaves the same under a router. Solid hard maple and white oak hold crisp edges and take threads reasonably well, so they suit jigs, fixtures and wear parts. Plywood and MDF are dimensionally stable and flat, which makes them the default for panels, enclosures and speaker baffles. Particleboard is cheap but chips out at the edge unless you cut with a compression tool.

Moisture content decides more than species. Kiln-dried stock at 6–8% moves little after machining. Green or air-dried boards can twist a week after they leave the machine, and no fixturing trick fixes that. For panels, we ask for the grade and the face veneer, because a void in the core of cheap plywood will show up as a blowout on a 3 mm wall.

Composite sheets behave differently again. Carbon fibre and G10 cut with abrasive tooling and need dust extraction, while MDF dust is fine enough to clog a shop vacuum in an hour. We match the cutter geometry and feed rate to the material rather than running one program across the whole job.

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  Solid hardwoodHolds edges and threads; watch grain direction on long thin parts.
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  Plywood / MDFFlat and stable; use compression cutters to avoid edge tear-out.
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  CompositesAbrasive and dusty; needs extraction and wear-resistant tooling.
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  Moisture6–8% kiln-dried stock stays put after machining.

Wood moves with humidity, so quoting metal tolerances on a wood part sets the job up to fail. On a stable panel like MDF or plywood, a router holds ±0.1 mm on profile and hole position across a 1,200 mm sheet. On solid hardwood, expect ±0.2 mm and plan for a slip fit rather than a press fit. Those numbers assume the stock is acclimated and the fixture is rigid.

The tight numbers in our shop, ±0.005 mm, belong to metal work on the same machines. They are not a promise for a maple bracket. What matters more for wood is flatness and repeatability between parts, since a stack of ten panels has to line up when it is assembled.

If a wood part carries a metal insert, we machine the pocket on the router and press the insert with a light interference fit, then check position with a pin gauge. Mixing materials in one assembly is common on control panels and instrument housings, and it is where tolerance stack-up usually bites.

Holding a wood part is half the job. Thin panels flex under cutter load, so we use a vacuum table with a spoilboard for sheet work, and toggle clamps or a custom fixture for solid blanks. On parts thinner than 6 mm, we leave tabs or cut onto a sacrificial layer so the piece does not lift at the last pass.

Cut direction matters on solid wood. Climb cutting gives a cleaner edge on most hardwoods but pulls the part toward the cutter, so the fixture has to resist that. On figured grain, a light finishing pass at 0.3 mm removes the fuzz left by the roughing pass.

For 3D contours, a 5-axis router reaches undercuts and angled faces in one setup. A 3-axis machine can do the same shape, but it usually needs the part flipped, which doubles the handling and adds a re-datum error of 0.05–0.1 mm. On a short run that re-datum is the main source of scrap.

We start with your STEP, IGES or DXF file and run DFM analysis within 12 hours. That check flags thin walls, deep pockets that need a long reach tool, and grain direction issues before any stock is cut. Production can start within 24 hours of approval, and parts ship in 3–5 days.

Toolpath is planned around the smallest internal radius, since a 6 mm cutter will not clear a 3 mm corner. If your design needs a sharp internal corner, we either change the tool or leave a radius and note it on the drawing. That conversation happens at the quoting stage, not after the first part is scrapped.

Every part gets a raw material check, in-process monitoring and a final inspection before it leaves the shop. Inspection reports are available on request. Uploads stay confidential, and we sign an NDA when a program or drawing needs that protection.