How Insert Bench works

You enter the inside sizes you need. The tool adds the board around and between them, then checks its own cut list by rebuilding the tray from it.

Tray geometry

For board thickness t, compartment widths w₁…wₙ, compartment lengths l₁…lₘ and tray height H (outside, including the base):

• Outside width X = Σw + (n + 1)·t, outside length Y = Σl + (m + 1)·t, inside depth H − t.
• Walls on base: base X × Y, long walls X × (H − t), short walls (Y − 2t) × (H − t).
• Walls around base: base (X − 2t) × (Y − 2t), long walls X × H, short walls (Y − 2t) × H.
• Butt-jointed dividers (height H − t): cross dividers run the full inside width X − 2t. Length-wise dividers are cut into one piece per row, each piece equal to that row's length.
• Half-lap dividers: both sets run the full inside span. Each crossing gets a notch t + extra width wide and (H − t)/2 deep. The notches are cut from the top on cross dividers and from the bottom on length-wise dividers.
• Lid: a flat X × Y panel that adds t to the height.

The independent check

Separately from the formulas, a checker takes each part's cut size from the cut list and places it in 3D, following the assembly instructions. Then it:

1. looks for any two parts occupying the same space, allowing only matching half-lap notches,
2. checks that every short wall and divider end touches the part it butts against, so there are no gaps,
3. casts rays from the centre of every compartment to measure its width, length and depth, and compares them with what you asked for,
4. checks that the outer size matches and that the base and lid fit the walls.

The box check then confirms that every tray sits inside the box with your clearance, that no two trays overlap, that each height (including any lid) is below the lid clearance, and that components fit their compartments with slack.

Sheets and exports

Parts are packed onto board sheets with a MaxRects rectangle packer, trying four sort orders, with rotation allowed and spacing between parts. The PDF prints at a stated scale with a 50 mm check bar. The SVG is drawn at true size in millimetres. Cut to the numbers in the cut list, not by measuring the drawing.

Tests

The engine tests include hand-checked examples for both base styles and both joint styles, and two trays from a published 5 mm plan (Esoteric Order of Gamers, BattleLore 2nd Edition). Every one reproduces the published part sizes exactly. A property test rebuilds 1,600 random trays (400 shapes in each base and joint style, across five board thicknesses), and broken cut lists confirm the checker catches mistakes. Browser tests run on desktop and mobile layouts and log every network request. Results are in the project's test report.

Limits

• Rectangular trays on a regular grid only. There are no irregular sub-compartments, angled walls, scoops, finger holes or lips.
• The geometry is exact; your cuts and board aren't. Fit is never guaranteed, so measure and test-fit.
• The sheet count comes from a heuristic and may not be the minimum.
• Trays are single-layer in the box. Stacked trays aren't height-checked against each other.