When it comes to metal fabrication equipment, you may have heard of an angle roll bending machine. Some may refer to it as a section busbar machine, but its purpose is still the same – form raw pieces of metal into desired shapes and sizes.
If you have ever seen an angle roll bending machine, you would agree that most are constructed in a vertical steel frame. It is common that the bending portion of the machine is located on one side, with the power and drive of the machine on the opposite side.
This writing is intended to educate and help the purchaser of Angle Bending Machines to ask the right questions when considering a purchase.
Small units are powered by an electric motor with a reducer. The power transmission is accomplished by gear trains and or chains / sprockets combinations. These are units used in small job shops and rod iron fabricating establishments. The new generation of the section bending machines is powered by hydraulic systems. These are used for bending from the smallest bars to very large wide flanged structural beams.
The large hydraulic units have a double pump hydraulic system, with one providing the flow for the rotation of the rolls and the other for the extension and retraction of hydraulic cylinders attached to arms carrying the bending rolls.
Some designs use one main hydraulic motor, usually mounted to an epicyclical in-line reduction gear, which imparts rotation to all three rolls. Another variation is each roll having its individual hydraulic motor/ reduction box combination directly driving it.
The Bending Process:
There are some terms used in the industry describing the capacities of Section Bending Machines and the process used, which the purchaser should become familiar with.
Square and rectangular rods, round rods, square and rectangular tubing, round tubing, standard pipe, equal leg and unequal leg angles, “C” and “MC” channel, “S” and “WF” beams, “T” bars …these are sections which can be rolled on section bending machines.
“Leg out” means the leg of a section, like in angles will stick outward from the ring formed in a radial direction. “Leg in” means the leg of a section, like in angles will stick inward from the ring formed in a radial direction toward the center of the ring. “Leg out” is also known as “Easy way” and “Leg in “Hard way” There are exceptions to this terminology when it comes to channels, whereby one can bend a channel leg in, leg out and the hard way when bent on its side.
Bending of round sections, pipes and round tubing require special tooling other than what is usually provided standard with section bending machines. In special cases with square and rectangular tubing where the wall thickness is low…the manufacturer should be consulted as to whether special all section enveloping tooling is required to avoid the section from collapsing under the bending forces.