What is a CNC router?
A CNC router is a router that a computer moves. You draw the part, CAM software turns it into toolpaths (G-code), and the machine moves the bit in X, Y and Z to cut it. This guide covers how a router differs from a CNC mill, the parts you will hear about, hobby machines in the makers’ own published figures, the bits, and the makers’ safety rules. Each line names the sources behind it.
CNC router vs CNC mill
A CNC router is usually a gantry machine: the work stays still on the bed while the gantry carries the cutter over it, which leaves room for a large working area and sheet goods.
A CNC mill usually moves the table (and the work) in X and Y, and the spindle only up and down in Z.
A mill is more rigid and holds tighter tolerances, so it can cut steel; a router is built for wood, plastics and foam, and some cut aluminum and other soft metals.
Sources
The parts: gantry, spindle or trim router, collet, spoilboard, workholding
The gantry is the bridge that spans the bed and carries the Z axis. On the Z axis sits the cutting head: a trim router or a spindle, clamped in a mount sized to its body. The bit goes in a collet, the work sits on a spoilboard, and workholding keeps it from moving.
A trim router costs less than a spindle, but it has less power and is louder.
A VFD (three-phase) spindle is quieter, with more power and less runout, but it costs more and takes more setting up.
65 mm is a common router and spindle mount size on hobby machines.
Carbide 3D’s compact router (a trim router with its base removed) takes shanks up to 1/4 in; its VFD spindles take up to 3/8 in (65 mm) or 1/2 in (80 mm).
One source: Carbide 3D, the maker of those spindles , sources [1]
A collet is a split steel sleeve that grips the bit’s shank; the nut squeezes it into the taper. Use the collet that matches the shank, often 1/4 in or 1/8 in.
Snap the collet into its nut before putting the bit in, and wipe dust off the taper.
One source: Carbide 3D, a machine maker, for its ER collets , sources [6]
A spoilboard (wasteboard) is a sheet, often MDF, fastened to the machine’s bed: the bit can cut into it instead of the bed, and it carries the workholding.
Surface the spoilboard on the machine with a wide bit so it is flat and parallel to the machine’s travel.
Hold the stock so it cannot shift: screws, tape and CA glue, hot glue, clamps, T-track, threaded inserts, a vise, dog holes or vacuum, with tabs to keep cut-out parts in place.
One source: Sienci Labs, a hobby CNC maker, in its workholding guide , sources [9]
Sources
- Carbide 3D, Spindle comparison: Carbide Compact Router vs VFD spindles, read 2026-11-08
- Sienci Labs, Common CNC terms: collet, router, spindle, read 2026-11-08
- Sienci Labs, LongMill MK2 routers and spindles: trim routers, 65 mm mount, three-phase spindles, read 2026-11-08
- Carbide 3D, Shapeoko 5 Pro specifications, read 2026-11-08
- Onefinity CNC, Compare machines: Apprentice and Elite Woodworker, Journeyman, Foreman, read 2026-11-08
- Carbide 3D, ER collet basics, read 2026-11-08
- Sienci Labs, LongMill MK2 wasteboard: fixtures and surfacing, read 2026-11-08
- Avid CNC, PRO CNC and Standard CNC machines: CNC spoilboard, read 2026-11-08
- Sienci Labs, CNC workholding, read 2026-11-08
Hobby CNC machines, as their makers state them
Each row is one maker’s published figures for its own machine, read from the maker’s site on 7–8 November 2026. Makers measure differently (machine travel, working area or cutting area), so the term each one uses is shown. Rows run alphabetically by maker; the order is not a ranking, and figures change, so check the maker before you buy. The last column is our geometry: the largest standard piece of a 4 × 8 ft sheet that fits the stated area in one setup.
| Machine | Maker’s term | X × Y (in) | X × Y (mm) | Z travel (in) | Motion | Router or spindle | Fits in one setup |
|---|---|---|---|---|---|---|---|
| Avid PRO4848Avid CNC | work area | 49.5 × 49.5 | 1260 × 1260 | 8 | Rack and pinion in X/Y, ballscrew Z, profile linear rails | Spindle systems sold as options (4 HP, 8.7 HP) | Half sheet (4 × 4 ft) |
| Shapeoko 5 Pro 2x2Carbide 3D | machine travel | 24.53 × 24.53 | — | 6.1 | 16 mm ballscrews in X/Y, HG-15 linear rails | 65 mm mount; router or VFD spindle bought separately | 2 × 2 ft panel |
| Shapeoko 5 Pro 4x2Carbide 3D | machine travel | 48.7 × 24.53 | — | 6.1 | 16 mm ballscrews in X/Y, HG-15 linear rails | 65 mm mount; router or VFD spindle bought separately | Quarter sheet (2 × 4 ft) |
| Shapeoko 5 Pro 4x4Carbide 3D | machine travel | 48.7 × 48.7 | — | 6.1 | 16 mm ballscrews in X/Y, HG-15 linear rails | 65 mm mount; router or VFD spindle bought separately | Half sheet (4 × 4 ft) |
| Onefinity ApprenticeOnefinity CNC | cutting area | 16.5 × 16.5 | 419 × 419 | 4.5 | 1610 ballscrews in X/Y | 65 mm mount | Smaller than 2 × 2 ft |
| Onefinity Elite WoodworkerOnefinity CNC | cutting area | 33 × 33 | 838 × 838 | 6.4 | 1616 ballscrews | 80 or 65 mm mount; Makita-type trim router fits | 2 × 2 ft panel |
| Onefinity Elite JourneymanOnefinity CNC | cutting area | 49 × 33 | 1245 × 838 | 6.4 | 1616 ballscrews | 80 or 65 mm mount; Makita-type trim router fits | Quarter sheet (2 × 4 ft) |
| Onefinity Elite ForemanOnefinity CNC | cutting area | 49 × 49.175 | 1245 × 1248 | 6.4 | 1616 ballscrews | 80 or 65 mm mount; Makita-type trim router fits | Half sheet (4 × 4 ft) |
| LongMill MK2 12x30Sienci Labs | working area | 32.28 × 14.48 | 820 × 368 | 4.9 | Delrin V-wheels on aluminum rails, 8 mm ACME lead screws | 65 mm mount; trim router or spindle (15,000–25,000 RPM, up to 2.7 kg) | Smaller than 2 × 2 ft |
| LongMill MK2 30x30Sienci Labs | working area | 32.28 × 34.17 | 820 × 868 | 4.9 | Delrin V-wheels on aluminum rails, 8 mm ACME lead screws | 65 mm mount; trim router or spindle (15,000–25,000 RPM, up to 2.7 kg) | 2 × 2 ft panel |
Sienci gives the LongMill’s Z travel as about 125 mm (4.9 in), and says add-ons can change it. A “—” means the maker did not publish that figure on the page we read. Lay out sheet parts with the plywood cut list calculator or the cut list calculator.
CNC bits
CNC bits come in three common tip shapes: flat end (square) for pockets and profiles, ball nose for 3D shapes, and V-bits for engraving and V-carving.
One source: Sienci Labs, a hobby CNC maker, in its cutting tool guide , sources [1]
A narrower V-bit cuts deeper for the same width: a 60° bit goes deeper than a 90° bit.
One source: Sienci Labs, a hobby CNC maker, in its cutting tool guide , sources [1]
Sources
- Sienci Labs, CNC cutting tools: flat end, ball nose and V-bits, read 2026-11-08
Profiles, shank sizes and what each router bit is for are in the router bit guide. To set the feed rate and RPM for a bit, use the CNC feeds and speeds calculator and the CNC chip load chart; for a handheld or table router, the router bit speed calculator.
CNC safety, from the makers
Wear eye protection: safety glasses or goggles.
No loose clothing or jewelry, and tie back long hair.
Never hold the work by hand or reach into the machine while it runs: clamp the work, and pause the job first.
Never leave the machine running unattended.
Wear hearing protection, and a mask or respirator for the dust.
Material can ignite while cutting, and chips and dust can hide smouldering embers, including in the dust bin.
Two sources: Sienci Labs and Grizzly Industrial , sources [2, 3]
Use the recommended feeds and speeds, don’t let the bit dwell in one spot, and have a fire plan.
One source: Grizzly Industrial, a CNC router maker, in its manual , sources [3]
Disconnect power before changing bits, and take the wrenches off the spindle before starting.
One source: Grizzly Industrial, a CNC router maker, in its manual , sources [3]
Don’t collect metal chips in the same bin as wood dust.
One source: Sienci Labs, a hobby CNC maker, in its safety guide , sources [2]
Sources
- Carbide 3D, Machine safety, read 2026-11-08
- Sienci Labs, CNC safety, read 2026-11-08
- Grizzly Industrial, G0894 CNC router owner’s manual: additional safety for CNC routers (p. 14), read 2026-11-08
The other shop machines’ rules are in the woodworking machine safety guide.