How to clean up traced artwork before CNC cutting

Traced artwork often has more detail than a router bit can cut. Clean it up once, in your design software, before it goes to CAM or nesting.

Should the cut line follow every detail?

No. A round bit cannot cut an inside corner sharper than its own radius. A 1/4 in bit leaves inside corners with a radius of at least 1/8 in; a 1/8 in bit leaves at least 1/16 in. Any detail smaller than that is simply rounded off by the bit, so tracing it only adds nodes.

Bit diameter	Smallest inside corner radius	Narrowest slot it can cut
1/16 in	1/32 in (0.8 mm)	1/16 in
1/8 in	1/16 in (1.6 mm)	1/8 in
1/4 in	1/8 in (3.2 mm)	1/4 in

If a sharp inside corner really matters, cut it with a smaller bit, or finish it by hand. Outside corners can stay sharp with any bit.

What to fix in a traced file

Too many tiny nodes. Tracing makes hundreds of short segments. The machine slows down on each one and the edge comes out rough. Simplify the curves until the shape still looks right at full size.
Duplicate lines. Two lines on top of each other are cut twice. Delete the copy.
Overlapping shapes. Pieces that cross each other should be welded (united) into one outline, or the bit follows both.
Open outlines. Every cut shape should be a closed path. Join the ends.
Stray bits. Tiny specks left by the trace. Delete anything smaller than the bit can cut.
Thin spots. Areas thinner than the bit, such as thin serifs, either can’t be cut or may break. Thicken them or remove them.

Clean up in design software or in CAM?

Most shops clean up in the design software (Illustrator, CorelDRAW, Inkscape) and send CAM a clean file. Then the same clean outlines go to nesting, toolpaths and the customer proof, and you only fix the file once. Use CAM for things that belong to the tool: offsets, the bit, depths and tabs.

How NestSigns helps

When you open a file, NestSigns runs a file check before nesting. It counts duplicate lines, overlapping shapes, open outlines, parts with too many tiny nodes, stray bits, gaps narrower than the bit and spots thinner than the bit, and marks them on the preview. Duplicate lines, tiny nodes and stray bits have a one-click fix (Remove duplicates, Simplify, Remove them). Overlapping shapes are cut as they are, so weld them in your design software.

Try it on your own job. Open your artwork, pick a sheet, and see how many sheets you need. 20 free nesting runs, no credit card. After that, $14.99 per month, cancel anytime.
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