Glossary
1 MIN READ
Spring-back
The natural tendency of a metal plate or profile to partially return toward its original flat shape after the forming force is released, due to elastic recovery.
Technical FAQ
Eliminating material waste and avoiding secondary cutting operations is a primary goal for high-productivity job shops looking to protect their margins. A flat end is the straight, unbent section left at the leading and trailing edges of a plate because the material cannot physically reach the exact tangent contact point between the machine rolls. Minimizing this straight section directly reduces material scrap and eliminates the time-consuming process of pre-bending plates on a separate press brake, thereby accelerating overall floor cycle times. Utilizing Davi all-rolls-drive technology ensures the plate can be positioned precisely at the tangent point to achieve the shortest flat end possible without compromising safety.
Dealing with high-yield structural steels can cause unexpected spring-back, leading to inconsistent part dimensions and slowed production lines. Yield strength is the specific stress threshold where a metal permanently deforms, meaning higher yield materials require significantly more bending power from the rolls to transition from elastic to plastic deformation. Recognizing your material's specific yield properties allows you to correctly gauge machine capacity, preventing equipment overload while ensuring accurate dimensional results. The Davi iRoll control system features a comprehensive material library that automatically factors in yield strength to calculate exact bending programs.
Inaccurate radius tracking due to material elasticity leads to continuous trial-and-error adjustments, resulting in costly scrap and slow assembly lines. Spring-back is the natural tendency of a metal plate or profile to partially return toward its original flat shape after the forming force is released, caused by elastic recovery. Accurate spring-back prediction allows the control system to over-bend the plate precisely, achieving the exact target radius on the first attempt without wasting time or material. Davi offers dedicated Spring-Back Software that analyzes material properties to eliminate manual guesswork and minimize test scrap.
Large-diameter, thin-walled shells can collapse or distort under their own weight during the top half of the rolling cycle. Overhead supports are heavy-duty vertical gantries equipped with hydraulic or electric lifting heads that support the plate from above. They prevent material deformation, ensure accurate geometry tracking, and allow a single operator to manage large parts safely without an overhead crane. Davi designs fully integrated, CNC-controlled overhead supports tailored to match the maximum capacity of its rolling lines.
"Barrel" defects (where the center diameter is larger than the ends) and "reel" or hourglass defects (where the center diameter is smaller) are caused by unequal pressure distribution along the plate width during rolling. Davi resolves these issues through:
- Engineered Roll Crowning: Offsetting predicted mechanical deflection.
- Servo-Tronic Parallelism: Dual hydraulic and electronic controls that keep rolls parallel under unbalanced loads.
- Variable Interaxis Spacing: On MAV 3-roll machines, adjusting side-roll spacing optimizes leverage and minimizes roll bending stress.