Turn the X-Y-Z bend coordinates from a drawing into the bender setup sequence — the feed (Y), rotation (B) and bend angle (C) for each bend, plus arc and tangent. Same maths as the bend-procedure sheet, machine-side.
Enter the apex / intersection points (PT 0 = start, then each bend vertex, last = end) — the same points as the drawing's bend table. Bends happen at the interior points.
Feed (Y) = straight to advance before each bend (tangent-corrected, uses CLR). Rotate (B) = roll between planes; the first bend has none (datum). Bend (C / DOB) = degrees the machine bends through = 180° − included angle. Springback is not applied — overbend per your own test bends.
CAD models and inspection reports describe a bent tube as a list of centreline node points in Cartesian X, Y, Z space. A rotary-draw bending machine cannot use those coordinates directly — it runs a three-step cycle per bend and needs the tube described in machine terms: Y (the linear feed before the bend), B (the plane-of-bend rotation), and C (the bend angle). This converter performs that translation, which is the single most error-prone hand calculation in tube-bend setup.
Y — feed: the straight length of tube pushed through the machine before a bend is struck, equal to the distance between consecutive node points minus the material already consumed by adjacent arcs. B — rotation: the angle the tube is rolled about its own axis so the next bend lands in the correct plane. This is the value humans get wrong, because it is the dihedral angle between two successive bend planes, not a simple coordinate difference — a sign error here mirrors the whole part. C — bend angle: the included angle of the arc, derived from the change in centreline direction at the node.
The plane-of-bend rotation B is computed as the signed angle between the plane of the previous bend and the plane of the next, measured about the tube axis. Its sign depends on your machine's handedness convention (clockwise-positive looking along the feed, or the mirror). Because the third and later bends compound earlier rotations, a small convention mismatch does not just tilt one bend — it corrupts every bend after it. Always verify the first converted part against a known-good sample before trusting a full program, and use the handedness setting if the twist comes out mirrored.
Feed the node coordinates from your drawing or CAD export, read the YBC table, and load it to the machine. To see the resulting bend sequence animate one step at a time — and to check how the plane of bend rotates at each station — use the bend sequence visualizer. To get raw-tube cut length from the same coordinates, use the tube bend calculator.