A03 / Open-top junction panels

A03 · Angled horizontal tee · open panel fitting

Angled horizontal tee · open panel fitting: solve branch openings, true panel patterns and an open-top fitting in 3D.

Beta · panel geometry

Plan your rise

Edit dimensions ↑
Panel 1U 800 · B 800 · S 200 mmPanel 2U 800 · B 800 · S 50 mmPanel 3U 313.4 · B 313.4 · S 50 mmPanel 4U 313.4 · B 313.4 · S 50 mmPanel 5U 393.3 · B 306.7 · S 150 mmPanel 6U 306.7 · B 306.7 · S 50 mmPanel 7U 393.3 · B 393.3 · S 50 mm

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Assemble the floor and side panels and join their butt seams. No retained material hinge or fastening detail is implied.

True-size panel patterns

Panel 1U 800 · B 800 · S 200 mmPanel 2U 800 · B 800 · S 50 mmPanel 3U 313.4 · B 313.4 · S 50 mmPanel 4U 313.4 · B 313.4 · S 50 mmPanel 5U 393.3 · B 306.7 · S 150 mmPanel 6U 306.7 · B 306.7 · S 50 mmPanel 7U 393.3 · B 393.3 · S 50 mm
PanelUpper edgeLower edgeTrue face heightLeft corner edgeRight corner edge
1800 mm800 mm200 mm200 mm200 mm
2800 mm800 mm50 mm50 mm50 mm
3313.4 mm313.4 mm50 mm50 mm50 mm
4313.4 mm313.4 mm50 mm50 mm50 mm
5393.3 mm306.7 mm150 mm173.21 mm150 mm
6306.7 mm306.7 mm50 mm50 mm50 mm
7393.3 mm393.3 mm50 mm50 mm50 mm

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.

Measure the main run and branches

Main and branch widths are measured across the base. Lead and tail run from the branch center along the main tray. Branch length runs from the main-side-wall intersection at the branch center to the outlet. All walls share the entered height. The main wall is cut away across the full branch opening; the top remains open. Separate panels are joined at butt seams, not folded from a single tray.

The branch opening is B / sin β along the main wall. End regions and branch length must leave at least 10 mm beyond the cut envelope. C29 selects three or four ports; opposite branches share the same dimensions.

How the flat patterns are calculated

Opening O = B / sin β; each branch end setback is ±(B / 2) cot β. The main wall is removed between these intersections. All floor and wall panels are unfolded by rigid planar coordinates; net area is the sum of their actual polygon areas.

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

W 200 mm · B 150 mm · H 50 mm · 400 + 400 mm · 7 panels True face height: 200.00 mm / 50.00 mm / 50.00 mm / 50.00 mm / 150.00 mm / 50.00 mm / 50.00 mm.

Fabrication and assembly method

  1. Inspect separate panel blanks for the open-top junction; this is not one continuous tray.
  2. Mark the true panel boundaries and the opening in each attaching main side wall.
  3. Cut the panels and remove the main-wall opening; no wall remains across a branch entrance.
  4. Assemble the floor and side panels and join their butt seams. No retained material hinge or fastening detail is implied.

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

Rectangular transition: face-height equations ↗
NPTEL · True-length development ↗

Related calculators

Other horizontal junction ↗
All numbered methods ↗