The distance between the straightener and the pay-off or final deflection of the product to be straightened has a major effect on the straightening result. A distance of A ≤ π · d, where d is twice the initial curvature radius or the diameter of the last deflecting roll, guarantees that the initial curvatures will be effectively changed by the straightening process and that the product to be straightened will leave the straightening system with the required final curvature and enter the follow-up machine in a defined condition.
If this distance is exceeded there is a real risk of the product - still under the influence of its initial curvature - turning and twisting before it enters the straightener so that its forming takes place neither constantly nor in the plane of curvature requiring straightening.
See Also
Adapted from “"We do it straight" — Wire Straightening”, p. 107 (ISBN 3-00-005897-4).