Step by step, formulas and common mistakes of sheet metal layout: cone, lobster back bend, square to round and the neutral axis. Each guide links to the part that calculates it.
How to lay out a truncated cone (frustum) on plate: the formula for the slant height, both sector radii and the sector angle, the thickness offset on the neutral axis, marking out with a trammel and the mistakes that stop the seam closing.
How to work out and lay out a segmented 90° bend, the lobster back: the half-mitre, the formula for the cut height at every element, the ordinate table of the worked example, how many plates to cut and the mistakes that leave the bend crooked.
How to develop a square or rectangle to round transition by triangulation: the true lengths, the chord of the circle, the order in which the triangles are built, the worked example and the mistakes that stop the part closing.
Who operates Planichapa and how each of the 50 flat patterns is checked: constructible triangles, zero weld error, plate area against solid area, figures published by third parties and the neutral axis on every part. And the mistakes we have already fixed, with dates.