The bending direction of a tube bending machine is determined by looking down on the bend die. If it rotates clockwise when bending it is “right-hand”. Conversely, if it rotates counter clockwise, it is “left-hand”.
The ability to perform the tube bending cycle in a left or right only direction, or bi-directionally, has a significant impact on the feasibility (from a geometric point of view) of part bending and therefore on the complexity of the part design.
Simulation of the bending cycle in VGP3D of a part is equally feasible on right-hand or left-hand tube bending machines only.
The three main types of tube bending machines
Regarding the bending direction, there are three main types of tube bending machines:
Tube bending machines with either right-hand or left-hand bending capability
These are tube bending machines that will rotate in only a left-hand or right-hand direction. These machines are suitable for bending the tube according to simple geometries or only according to their bending direction.
The following video shows the programming and simulation on VGP3D of a part feasible only on a right-hand bending machine. The simulation shows the collision that would occur if the same part were to be bent on a left-hand machine.
Simulation of the bending cycle in VGP3D of a part feasible only on right-hand tube bending machines.
Tube bending machines with single-cycle right-hand and left-hand capability
This bi-directional tube bending machine, also known as single-cycle or in automatic process right and left-hand bending machine, can change bending directions on the fly (to avoid interference of the tube hitting the machine, tooling or floor during the part forming process) and is suitable for producing complex-shaped parts.
Manufacturers in sectors such as furniture, automotive, and air conditioning depend on the flexibility and output these machines offer. Subcontractors, who are faced with ever-changing part requests, require the maximum feasibility from a geometric point of view, to fulfil the orders also depend on these single-cycle bending machines.
The following video shows the programming and simulation on VGP3D of a part feasible only on right-hand and left-hand single cycle bending machine.
Simulation of the bending cycle in VGP3D of a part feasible only on single-cycle right and left-hand tube bending machines.
Tube bending machines with configurable either right-hand or left-hand bending capability
This type of tube bending machine is an excellent solution for manufacturers who do not want to have a machine that is either only "right-hand" or only "left-hand" for various reasons including low production volume for one of the two types, space availability, investment limits, etc. On these machines, the bending head and the handling mechanisms are designed so that the customer can change the configuration of the machine from "right-hand" to "left-hand" (or vice versa) by disassembling and reassembling the head components in the opposite position.
Many manufacturers choose to have a fleet of machines consisting of several types of tube benders. This allows them to direct the production of certain types of parts towards the most suitable machine (size, complexity, quantity) and optimize the entire production process.
In this optimization determination phase, the VGP3D software allows the customer to verify the part feasibility on a specific machine without stopping production, allowing them to select the best machine for production.
Tractor cab frame components made with ELECT tube bending machines.
When and why should you choose a single direction tube bending machine?
Diameter is the first distinguishing element when selecting a tube bending machine. Beyond a certain dimension, the size of the head and the complexity of the bending tools make it inconvenient or impossible to design a system capable of performing single-cycle right-hand and left-hand bending. Similarly, beyond a certain diameter, it is very difficult to find parts with particularly complex geometry or to receive requests for this type of product. In this case, simple geometry parts that will be subsequently welded are much more common.
In addition to small workpieces with few bends, another example is that of large flat workpieces with few bends or closed in on themselves, which can be made on tube bending machines with only one bending direction. Typical applications are bed frames, agricultural machinery cabs, and components used in the livestock sector for example.
Detail made for the livestock sector with ELECT tube bending machine.
When and why should you choose a single-cycle right and left-hand tube bending machine?
A single-cycle right and left-hand tube bending machine can be used to make parts with many bends and also developed to accommodate complex three-dimensional shapes. The main advantage is far fewer limits in terms of the geometries that can be produced, and the part can be created in a single cycle thereby maximizing precision and productivity.
Typical applications of this type of tube bending machine can be found in the furniture sector. An example is the structure of furniture and chairs, shaped according to innovative forms that give designers the greatest creative freedom. These are pieces with a combination of fixed and/or variable radius curves that are developed on three dimensions.
Example of a magazine rack made from a single tube bent on a single-cycle right and left-hand tube bending machine: E-TURN.
Another typical application for these tube bending machines is when the tube must follow obligatory, sometimes very tortuous routes, due to the reduced space available in the system in which it will be inserted. This situation is common in engines, braking or air conditioning systems for automobiles and industrial vehicles, but also in other types of systems such as boilers, household appliances, etc. In these cases, the use of a right and left tube bending machine in a single cycle may be the only solution.
Tubular component for an automotive air conditioning system made with SMART single-cycle right and left-hand tube bending machines.
The versatility of this type of machine must also be accompanied by an off-line programming system that is equally versatile, powerful and necessarily simple to use.
The following video shows the programming and simulation of a part on VGP3D to be made on a BLM GROUP E-TURN in automatic process right and left-hand tube bending machine. In this application, you can see its simplicity of use and how the programming software speeds up the setting up of the part as a result of any collisions being resolved quickly and intuitively.
Simulation of collision resolution with a rapid change of bending direction on VGP3D.
In conclusion, choosing the type of tube bending machine best suited to your needs must primarily take into account the type of production you intend for the system; small pieces with few bends or parts with complex geometry with right and left-hand bends, large production batches or small series that may vary unpredictably in the future, large-diameter tubes or small tubes with obligatory forms.
BLM GROUP is a partner with over 60 years of experience in the tube processing sector that can help you make a wise and far-sighted choice. Contact us and talk to our experts.