Preparing files for CNC routing

Start with certainty

State the dimensions independently of the file.

Every enquiry should include at least one written overall dimension. This catches files exported in inches, pixels or an unexpected drawing scale. Do not rely on the file preview alone.

For vector files

• Use closed paths for profiles and cut-outs.
• Remove duplicate lines and tiny unwanted segments.
• Keep each operation on a clearly named layer where possible.
• Identify through-cuts separately from pockets and engraving.
• Convert live text to outlines only after spelling and layout have been approved.
• Do not add an offset for the cutter unless that has been specifically agreed.

For drawings and PDFs

• Include overall width, height and material thickness.
• Dimension hole centres from a clear datum.
• Identify the front and rear faces.
• State every pocket or rebate depth.
• Mark critical dimensions separately from reference dimensions.
• Include a section view where several depths overlap.

Internal corners

A rotating cutter leaves a radius in internal corners. A nominally square opening may need a corner radius, dog-bone relief or a changed mating part. State what must fit rather than assuming a square corner can be machined.

Photographs and sketches

A photograph or hand sketch is enough to decide whether a project is suitable, but it is not automatically production geometry. Add a ruler or known object for scale, take square-on views, and identify which measurements are known rather than estimated.