How to Export a Cut Plan to CNC: Formats, Workflow, and Tips

You’ve spent twenty minutes arranging 47 parts across three sheets of 4×8 ft plywood (1220×2440 mm), and CutOptim just handed you a layout with 92% yield. Now what? The optimizer did the hard part, but the gap between a screen layout and a finished CNC program catches a lot of operators off guard. This guide walks through every step — file format selection, CAM import, toolpath creation, and the mistakes that send jobs back to the drawing board.

What File Formats CNC Machines Accept

CNC controllers don’t all speak the same language. Here’s what you’ll encounter:

DXF (Drawing Exchange Format) — The most widely accepted 2D format. Every major CAM package imports it. DXF files describe geometry (lines, arcs, polylines) without toolpath data, so you still need to assign feeds, speeds, and tool numbers in your CAM software. Best for CNC routers and laser cutters.

SVG (Scalable Vector Graphics) — Common in laser cutting and vinyl/sign shops. SVG carries vector geometry similar to DXF but uses a web-standard XML structure. Some CAM tools accept it; most industrial controllers don’t directly.

G-code — The actual machine instruction set. G-code files include coordinates, feed rates, spindle speeds, and tool changes. You typically don’t export G-code directly from an optimizer — it’s generated by your CAM software’s post-processor after you define toolpaths.

Proprietary formats — Controllers from Biesse, Homag, SCM, and others accept their own file types (.bpp, .mpr, .xxl). If your machine uses one of these, your CAM package needs the matching post-processor.

From Optimized Layout to Machine-Ready File

1. Optimize your cut plan in CutOptim

   Enter your stock panels (e.g., 2440×1220 mm for a standard 4×8 sheet), list every required part with dimensions, set your blade kerf (typically 3–4 mm for a CNC router bit), and run the optimizer. Review the visual layout and yield percentage before moving on.

2. Export as DXF or SVG

   Download the optimized layout. DXF is the safer choice for CNC routers — it preserves exact dimensions and is universally supported. Use SVG if your workflow involves laser cutting or your CAM tool specifically prefers it.

3. Import into your CAM software

   Open the file in your CAM package — Fusion 360, Vectric VCarve/Aspire, AlphaCAM, or similar. Verify that the geometry dimensions match your original values. If you see a 600 mm part showing as 0.6 mm, you have a units mismatch (see below).

4. Set toolpaths and cutting parameters

   Assign a profile toolpath (outside contour) to each part outline. Set your bit diameter, feed rate, plunge rate, depth per pass, and tab placement. Tabs keep parts from shifting mid-cut on CNC routers — 2–3 tabs per part, about 5 mm wide, usually works.

5. Post-process to G-code and send to the machine

   Select the post-processor that matches your controller (e.g., Mach3, GRBL, Fanuc, WinCNC). Generate the G-code file. Load it into your controller software or transfer via USB/network. Run a dry-run or air-cut first on unfamiliar setups.

Common CNC Export Errors (and Fixes)

Units mismatch — This is the single most frequent mistake. Your optimizer exports in millimeters, but your CAM software defaults to inches (or vice versa). The geometry imports at 1/25th or 25× the correct size. Always check one known dimension immediately after import.

Origin offset — The cut plan’s coordinate origin (0,0) may not match your machine’s home position. If parts appear shifted or off the sheet, adjust the origin in your CAM software so geometry aligns with the physical sheet corner where your machine zeros.

Missing kerf compensation — If kerf was already applied in CutOptim, don’t add it again in your CAM software. Double-kerf means every part comes out undersized by the kerf width. If kerf wasn’t applied in the optimizer, set it in CAM via the toolpath offset (outside for parts, inside for cutouts).

Unclosed polylines — Some DXF exports contain tiny gaps between line segments. CAM tools may refuse to create a toolpath on open geometry. Use your CAM’s “join” or “close vectors” function to fix gaps under 0.1 mm.

Wrong cutting direction — Climb vs. conventional milling matters for edge quality. Most CNC routers cut cleaner with climb milling (toolpath runs clockwise for outside profiles). Verify your CAM software’s default direction.

DXF vs SVG: Which Format to Use

Use DXF when you’re running a CNC router, panel saw with nesting capability, or any machine with industrial CAM software. DXF is the de facto standard in woodworking and sheet metal CNC. It handles arcs and polylines cleanly, and every CAM package on the market imports it without conversion.

Use SVG when you’re working with a laser cutter, a vinyl plotter, or browser-based CAM tools like LaserWeb or LightBurn. SVG is also handy if you need to preview or edit the layout in vector editors like Inkscape before sending to the machine.

Avoid SVG for precision-critical CNC routing. Some SVG renderers approximate arcs with short line segments, creating faceted edges. DXF preserves true arcs.

Setting Up Your CAM Workflow

A repeatable workflow saves more time than any single optimization run. Here’s what experienced shops do:

Keep a template file in your CAM software with your standard material thickness, bit size, feed rates, and post-processor already configured. When a new DXF comes in, open the template, import geometry, assign toolpaths, and post-process — three clicks instead of twenty settings.

Name your files consistently: job-material-sheetNumber.dxf (e.g., kitchen-plywood-01.dxf). When you’re post-processing twelve sheets for a cabinet job, you’ll thank yourself.

Store your post-processor configuration in version control or a shared drive. When a machine gets a firmware update, you’ll need to know exactly what changed.