One-Sided Cable Tray Reducer with One Edge Aligned

Choose the edge that stays aligned

A one-sided reducer preserves one straight tray edge while the opposite edge moves inward. The route centerline shifts toward the aligned side as the width decreases. Identify inlet and outlet when viewing the fitting, then follow the same physical side from one end to the other.

The worked layout reduces a 400 mm inlet to a 200 mm outlet over a 500 mm axial transition, with 50 mm side height. The aligned side has zero transverse movement. The opposite side moves inward by the complete 200 mm width reduction. The centerline moves by half that amount, giving a 100 mm shift.

The calculator displays one specified aligned-edge orientation. Use the straight common edge in the 3D model and the developed floor as the reference. Match that edge to the installation before transferring dimensions to material.

Calculate a separate true length for each wall

Let Δ be the full inlet-to-outlet width change and L the axial length. The aligned wall follows length L. The opposite wall follows the diagonal of a right triangle with legs L and Δ, so its true length is √(L² + Δ²).

For L = 500 mm and Δ = 200 mm, the sloping wall is √(500² + 200²) = 538.52 mm long. The aligned wall stays 500 mm long. Both walls are 50 mm high. The developed floor is a right trapezoid with 400 mm and 200 mm end edges and a 500 mm axial length.

Floor area is (400 + 200) × 500 / 2 = 150000 mm². The aligned wall adds 25000 mm² and the sloping wall adds 26925.82 mm², giving 201925.82 mm² of ideal panel area. Use full precision for calculations and round only the displayed dimensions.

Worked example dimensions

Match the three panels to the aligned edge

Mark the floor end widths, straight side and sloping side before separating the panels. Label the aligned and sloping walls so that their joining edges follow the corresponding floor edges. The floor and both walls preserve their true edge lengths during the assembly animation.

In the model, Original and Mark show the developed stock outlines and panel boundaries. Cut separates the three panels. Form assembles the floor and the two walls into the open-top transition. Inspect the straight common edge through the whole sequence.

A centered reducer distributes the width change equally between its two walls. For the same inlet, outlet and axial length, its wall lengths use half the width change in each triangle. Follow the linked centered-reducer guide to compare the two alignment choices using their own panel layouts.

Review the fabrication detail

The model develops ideal zero-thickness panels. Add the seam, joining, kerf and thickness allowances required by your fabrication process. Check the aligned edge and the outlet position against the selected tray and installation.