Laying out the parts on the laser bed

Between the finished design and the cut there is a step people tend to underrate: arranging the parts on the sheet. Done badly it costs material; done well it costs nothing, because the program does it.

The bed size

The “Material” panel has Width and Height of the cutting bed. Type in the usable size of your machine — the area the laser actually reaches, not the outside of the cabinet. On a 600 × 400 mm machine, the usable area is often 595 × 395.

From then on the layout arranges the parts inside that rectangle. Whatever does not fit goes on the next sheet, and arrows appear under the preview to move between them.

Leave both fields at zero and every part goes on a single sheet, as large as needed: fine for seeing the overall size, less so for actually cutting.

The gap between parts

The Part spacing field says how much room to leave between one outline and the next. It is not wasted space: it is where the heat goes. Two parts too close scorch each other along the edge, and on thin material they can warp.

Five millimetres is fine nearly always. Going down to two makes sense only on materials that do not burn, like acrylic, and when the sheet is genuinely tight.

How to save material

• Big parts first. The automatic layout already places them first, but if you add a large part after the fact it is worth re-exporting and letting it redo the arrangement.
• One material at a time. If a part has a different thickness from the rest, cutting it on the same sheet makes no sense: make it a separate project.
• Real offcuts. If you are using a scrap rather than a full sheet, put the size of the offcut in the cutting bed fields, not the machine's. The parts will be arranged inside that space.

Before sending it to cut

Look at the preview and check three things: that every part is there, that none of them touch, and that the overall size shown at the top fits your bed. The preview itself tells you how many sheets you need.

When you download, you get one file per sheet, numbered: plyjoin-cutting-layout-1.dxf, -2 and so on. Nothing to separate by hand.

Try it now

Open the app, type your bed size and watch the parts arrange themselves. Then add a large part and watch the second sheet appear.