Use the tabs at the top to choose a part type — Electronics Bay Sled (coupler version or slide-in payload bay design), Bulkhead, Centering Ring (also used for motor thrust rings and motor mounts), Fin, Baffle, Painting Stand, or Fin Alignment Guide — and enter your dimensions. Select tube presets from the database to auto-fill accurate diameters, or type dimensions manually.

Set the quantity you need, then click Add part(s) to sheet to place them on the cutting sheet. For electronics bays, use the Generate E-Bay parts button to automatically create a matched set of sled, bulkheads, brackets, and centering rings in one go.

Parts appear on the cutting sheet with a parts list to the right. Set your sheet size using the presets dropdown or enter custom dimensions. Use the checkboxes to select or deselect parts for export.

Click a part on the sheet to select it. Drag to move it around. Press Del to remove the selected part, or R to rotate a fin by 90°.

Click any part to open its editing panel. From here you can adjust the quantity (adds or removes copies), set a precise rotation angle, or flip/mirror the part.

You can also add custom holes anywhere on the part for wiring, vent holes, or fasteners — and mount altimeters to automatically place mounting hole patterns from a database of known altimeter dimensions. Both are covered in more detail in the next sections.

Click Add a Hole in the part panel to open the hole editor. First, click a green dot on the part outline to set your reference point — this makes it easy to position holes relative to corners or edges.

Then enter the hole diameter and X/Y offset from your reference point. Tick All identical parts to add the hole to every copy of this part on the sheet. Click Add Hole to place it, and repeat as needed.

Click Mount Altimeter to add altimeter mounting holes to a part. Choose an altimeter from the dropdown — the outline dimensions and default hole size are loaded from the database. Set the mounting hole diameter and rotation angle, then click Mount.

The altimeter appears as a red dashed overlay on the part. Drag it to position it exactly where you need it. You can add multiple altimeters to the same part and adjust the hole size and rotation from the part panel afterwards.

Click Auto Arrange / Nest to automatically pack all parts as tightly as possible. The nester runs thousands of passes trying random orderings and rotations to find the most compact layout. Use Compact for a quick single-pass arrangement.

Tick Allow mirror to let the nester flip parts for a tighter fit (useful for symmetrical parts). The progress display shows the best result found so far — click Stop & keep best at any time if you are happy with the layout.

Use the buttons at the bottom of the sheet to export your design. Export All downloads every part across all sheets, while Export Selected only includes parts ticked in the parts list.

Choose DXF for laser cutter software (AutoCAD R12 format, compatible with LightBurn, Illustrator, and K40 Whisperer) or SVG for general use. Both formats use millimetre units. Tick Sheet outline to include the sheet border in the export.

Click Save Sheet to save your entire design — all parts, positions, holes, altimeters, and sheet settings — to your account. Give it a name and you can come back to it later.

Click Open Sheet to load a previously saved design. Your saved sheets are listed with their date — click Open to restore the full layout, or the × button to delete a saved design.