Cone in Segments (Multi-Piece Cone)

Because the flat pattern of a large cone is bigger than any plate you can buy, or more than your rolls can take in one piece. Split it into identical segments and each one is cut, rolled and welded in turn. Every segment is the same piece of the same flat pattern, so one DXF and a count is all the shop needs.

It tries one segment, then two, three and so on, and stops at the first count whose segment fits your plate — laid with its chord along one plate edge, or turned 90°. It does not try other angles or put several segments on one plate, so a careful nest may do better; the count it gives is never too few for the orientation it checks.

Only in angle. Each segment has the same outer and inner radius as the whole flat pattern and an equal share of its angle, so the arcs add up to the circumferences and the radial edges are all the slant height.

Work as the cone tool does: enter mid-thickness diameters, or choose the inside or outside face and give the thickness, and the pattern is developed on the neutral layer. No weld gap or bevel allowance is added to the segment edges.

Swing the two radii from one centre, draw one radial edge, and fix the other by measuring the chord across the outer arc from the first — the chord is in the results. Check across the inner arc too. The cone guide walks through the same method for the whole pattern.