The parts of an open tray
- Bottom. Inner width and depth plus two thicknesses each way, with tabs on all four edges.
- Four walls. Inner height plus one thickness tall, because nothing sits on top. The upper edge is a plain straight line.
- Dividers along X. They split the width, so each is as long as the inner depth.
- Dividers along Y. They split the depth, so each is as long as the inner width.
Where dividers cross they get half-lap slots, half the height deep. They are not jointed into the walls: they rest on the bottom between them.
How the sheet layout is made
Parts are sorted tallest first and placed left to right in rows, without rotation. A part that would pass the right margin starts a new row. There is a 5 mm margin around the sheet and a gap between parts, 3 mm by default. The generator reports the area the rows need and warns you when it is larger than your sheet. It does not nest parts inside each other, so a hand-made layout can use less material.
Worked example: 200 × 150 × 50 mm, six compartments
Open tray, inner 200 × 150 × 50 mm, 3 mm sheet, kerf 0.2 mm, target finger width 12 mm, two dividers along X and one along Y. The outer size is 206 × 156 × 53 mm. The edges get 17 segments along the width, 13 along the depth and 5 along the height. Each compartment is 64.667 × 73.5 mm.
| Part | Pieces | Drawn size with kerf | Row |
|---|---|---|---|
| Bottom | 1 | 206.2 × 156.2 mm | 1 |
| Front and back walls | 2 | 206.2 × 53.2 mm | 1 and 2 |
| Left and right walls | 2 | 156.2 × 53.2 mm | 2 |
| Divider along Y | 1 | 200.2 × 50.2 mm | 3 |
| Dividers along X | 2 | 150.2 × 50.2 mm | 3 |
On the default 600 × 400 mm sheet these eight parts take three rows. The widest row ends at 529.6 mm, so with the margin the layout is 534.6 mm wide. Its height is 5 + 156.2 + 3 + 53.2 + 3 + 50.2 + 5 = 275.6 mm, and it fits the sheet. An automated script generates this tray and checks that no two parts are closer than the gap.
Free generators exist
Free and open-source box generators exist, and some draw trays with dividers too. This tool differs in one narrow way: a single form fits loose half-lap dividers to your inner dimensions and writes kerf-compensated SVG and DXF. If a free tool already draws the tray you want, use it.
Read this before you buy or cut
- Dimensions. You enter the inner width, depth and height. The outer size is the inner size plus two material thicknesses (an open tray has no lid panel, so its outer height is the inner height plus one thickness).
- Not test-cut. The geometry is computed and checked by a script (92 fixture assertions) but was never test-cut, so cut a test piece first and adjust kerf and material thickness.
- Made by AI agents. This tool and its code were generated by AI agents and no human maker has validated it.
- Price: $9 USD one-time.
- What the key unlocks: one licence key unlocks SVG and DXF download for any dimensions, in this browser tool.
- Refunds: Refund requests go through Gumroad, under Gumroad's refund policy.
- Free without a key. The form, the preview, the part list and the sheet size.