What is a CNC router service?
A CNC router is a computer-controlled spindle with a cutting bit that moves across a flat bed. A sheet of material is held down on the bed, and the router follows your file to cut shapes out, carve pockets or engrave a surface. It is the machine behind many cut-out signs, furniture parts, cabinet pieces, jigs and templates.
It is related to CNC machining but not the same thing. Routers are usually larger and lighter, built for sheet and board, and they are quick at cutting big flat parts. Machines in a machining shop are usually stiffer and better suited to metal and tight tolerances. For the metal side of the question, see CNC machining service.
What materials can it cut?
It depends on the machine and the bit, so ask. Typically a router handles:
- Wood and wood products such as plywood and MDF.
- Plastic sheet such as acrylic, PVC foam board or HDPE.
- Composite panels and some foam boards.
- Soft metals such as aluminium, on machines built for it. Many hobby routers are not.
Material choice affects the edge. Plywood can splinter on the top surface, MDF leaves a fine dust that needs sealing before painting, and acrylic can melt if the bit runs too slowly. A fabricator who works with the material every week knows the right bit and speed. If you are not sure what to pick, describe the job and let them suggest.
What can I make with one?
- Signs with cut-out letters or shapes, and carved or engraved signs.
- Furniture parts, shelves and cabinet panels.
- Templates and jigs that you then use with hand tools, such as router templates for repeat shapes.
- Stencils and fixtures.
- Large flat parts that would not fit on a printer or a laser.
For fine detail on thin material, a laser may do a better job. For raised, carved or thick work, a router is usually the better tool. The custom parts guide compares the main processes.
Why are inside corners rounded?
The cutter is a round bit that spins. When it follows the inside of a square cut-out, it leaves a curve in each corner equal to its radius. You cannot get a sharp inside corner with a round bit. This matters whenever a square part has to slot into a square hole.
There are ways around it. You can draw the corner with a small relief cut so a square part will seat, or you can round the outside corners of the part to match the hole. A fabricator who does this regularly will already know the trick. Tell them if a square corner matters.
What files and details should I send?
- A vector file for flat parts: DXF, SVG or a PDF drawn to scale. Include the real dimensions and say what the units are.
- Material and thickness. Sheet thickness varies, so give the actual figure and ask whether the shop can supply it.
- Whether each shape is cut all the way through, engraved to a depth or pocketed. Mark them on different layers or colours.
- The number of sheets or pieces.
- The finish: sanded edges, sealed, painted, or left raw from the machine.
- Where the part will live. Outdoor signs need different materials from indoor ones.
Ask how the sheet is held down and whether small pieces will be kept in place with tabs. You may see small tab marks on the edges that need trimming. Ask what is included in the price and how long it takes, and keep the agreed scope in the offer. How it works shows how the order proceeds from there.
Where do I start?
Open the fabricator directory, filter for CNC, and look for profiles that show sheet work. Message two or three with the same file and compare their answers. Browsing the marketplace can show designs that a fabricator may already be set up to cut. For the handover, read your first local pickup.