A02 · Open-tray expander · small to large

Measure the two openings

The inlet and outlet widths are measured across the base; side height is constant and transition length runs along the tray. This is an open U-section: one floor and two walls, with no top panel. Both sides reduce equally around a fixed centerline. The geometry is developed as three separate panels, with longitudinal joining seams.

The outlet must be wider than the inlet. The open top, level floor and constant wall height are preserved.

How the flat patterns are calculated

Floor panel: a trapezoid with inlet and outlet widths and axial length L. For each wall, true length is √(L² + Δ²), where Δ is that wall’s lateral change. Its panel height is the tray side height. Single-sided Δ values are 0 and Wᵢ−Wₒ; centered Δ values are both (Wᵢ−Wₒ)/2.

Each four-corner panel is unfolded by an isometry: all four edges and both diagonals match the 3D panel. The assembly animation rotates each panel rigidly about a reference edge. It does not interpolate or stretch the sheet.

Default example

400 → 600 mm · L 500 mm · H 50 mm True face height: 500.00 mm / 509.90 mm / 509.90 mm.

Fabrication and assembly method

1. Inspect three panel blanks for an open-top tray reducer.
2. Mark the bottom plate and both side-wall outlines.
3. Cut the three separate panels; the top stays open.
4. Assemble the floor and two walls. Join the long seams; reference edges are assembly datums, not retained hinges.

Ideal sharp, zero-thickness panel geometry. Panel dimensions exclude kerf, bend allowance, seams, overlap tabs, fasteners and the openings cut in the parent tray. The assembly is a separate-panel method; confirm the actual joining detail.

Independent TrayNeo panel-development method. Reference-product correspondence remains under review.

Geometry references

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