Laser Cutting Optimization

When a flat pattern has nested contours — a shape cut inside another shape — you can end up with extra, overlapping loops that make a laser cut the same edge twice. Laser-cut optimisation finds those redundant intermediate loops and removes them (or tucks them onto a hidden layer), so the laser cuts each real edge once.

It’s a setting in your Output Profile.

Professional Tier

Laser-cut optimisation is a Professional feature.

Where to set it

Export and click the green check to open the DXF Export Preview window.
Click the gear button next to the Profile drop-down (Edit DXF output profiles).
In the editor, click Laser in the left list (the section is titled Laser-cut optimisation). Clone a built-in profile first if needed.

Controls:

Filter intermediate contours for laser cutting — the master switch.
Tolerance — how close two endpoints must be to count as the same point (default 0.01 mm).
Intermediate contours — what to do with the redundant loops:
- Delete — remove them from the DXF.
- Move To Hidden Layer — keep them, but on a hidden layer.
Merge nearby endpoints first — stitch near-miss endpoints together before analysing, which helps loops close properly.

Start with Move To Hidden Layer

The first time you use this on a new kind of part, pick Move To Hidden Layer and open the result in a viewer. You can confirm only the redundant loops were caught before switching to Delete.

What gets kept vs removed

CADshift builds a containment tree of the closed contours and keeps the ones that are real cuts:

Outer boundary        →  kept
 ├─ Slot              →  kept
 │   └─ Hole in slot  →  kept
 └─ Intermediate loop →  removed (it only wraps another cut)
     └─ Final hole    →  kept

In short: the outer boundary and the actual holes/slots stay; a loop whose only job is to wrap another loop is the redundant one that gets removed.

Don't over-tighten the tolerance

The tolerance has a healthy range (roughly 1–25 µm). Too tight and outlines won’t join into closed loops; too loose and separate features get merged into one. The default is well chosen — only nudge it if loops aren’t closing.

Troubleshooting

Nothing was removed

The contours have to form closed loops and be truly nested (one fully inside another). Tiny gaps between lines can stop a loop from closing — try turning on Merge nearby endpoints first.

A real cut got removed

Switch to Move To Hidden Layer, open the DXF, and check the hidden layer. Overlapping or duplicate source geometry is the usual cause.

Next steps

Set layer names and colours — Layer Configuration
Shorten bend lines to stubs — Trim Bend Lines
See the whole profile system — DXF Output Profiles