Cone Flat-Pattern Development (Radial Line)

The flat blank a cone rolls up from, and the sweep to cut it.

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Example

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Details, formula, and sources

Flat pattern of a right cone: slant L = sqrt(r^2 + h^2), sector radius = L, sweep = 360 r / L. R 6 in, h 8 in -> L 10 in, 216-degree sector; a taller R 6/h 16 cone -> 17.09 in slant, a narrower 126-degree sector. Add seam and bend allowance. A layout aid; verify against a test piece.

L = sqrt(base_radius^2 + height^2); pattern radius = L; sweep = 360 x base_radius / L.

Radial-line development of a right cone, standard sheet-metal layout, by name.

The slant-height and sector-sweep relations are public sheet-metal layout geometry.

Estimate. AHJ and licensed professional govern.

Field names used by the API: base_radius_in, height_in, slant_L_in, sweep_deg

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