How to count pierces and measure cut length from a DXF

The counting rules

• One closed contour, one pierce. Aston Precision's estimator puts it the same way: each pierce is each time the laser starts a new cut.
• A slot, a notch or a window is one contour however long it is, so one pierce.
• A part cut inside another part's hole is a separate part with its own pierce; Zorocut finds it by containment and lists it on its own.
• Text, dimensions and hatches are not cut and add no pierces. Zorocut reports them as not cut, and ignores layers whose names mark dimensions, text, bend or construction lines.
• Marking and engraving lines do not cut through, so Zorocut does not count them as pierces.
• An open line has no inside, so it is not a part. Zorocut flags open contours as an error instead of guessing — see open contours.

How each DXF entity is measured

What Zorocut and the DXF checker report

The DXF checker runs the same import as the online nester and the desktop app, in your browser: the file never leaves your computer. For every part it shows the bounding box, the cut length in metres and the number of pierces. Before it counts, it cleans: duplicate segments are removed, because they would be cut twice; zero-length segments and specks under 0.2 mm go; gaps up to 0.1 mm are closed with a warning; and every repair is listed. Open contours and contours that cross themselves are errors, and a hole smaller than the thickness you enter is a warning. The cut length covers the outline and the holes, not marking lines; Zorocut also counts each part's corners for its time model, and the quote multiplies everything by the quantity.

What the DXF number leaves out

• Lead-ins and lead-outs: the controller adds them — CypCut sets their type, length and angle — so the real path is a little longer than the drawing.
• Kerf compensation and micro-joints are added at the machine too; see the CypCut manual for both.
• Shared cuts: CypCut's multi-contour cut joins a group with one connecting path to reduce the piercing times, and common-line cutting removes shared edges — both pierce less often than the drawing suggests. See common-line cutting.
• Rapid moves between contours cost time but add no cut length. A 2023 IEOM study that predicted sheet run times used the number of pierces and the rapid-move length as separate inputs.

Counting by hand is still common. In 2022 a plasma user on PlasmaSpider found no pierce count in SheetCam's job report and suggested “I suppose you could just count them manually”. Aston's estimator asks you to type the total cut length and pierces yourself, and offers a helper that multiplies a rectangle's outline by 1.0–2.0 for complexity — a guess, where the DXF already holds the exact figure.