Most often, the electro-hydraulic press brakes are classified under CNC press brakes. The torsion bar series, however, are classified under NC press brakes. This article is primarily focused on clarifying the differences between the two types, as well as outlining the respective advantages and drawbacks of each type. It aims to answer potential questions from buyers.
Many customers in the manufacturing sector are confused when it comes to choosing between NC and CNC press brakes. Both machines serve the same purpose but have different capabilities and features. This article will shed light on the differences between the two types of presses brakes, from different perspectives. It can help both professionals and newcomers make the right decision.
What is NC Press Brake?
We refer to the NC press brake when referring to a torsion bar press brake. Torsion bars are used in the torsion-bar synchronous press brake for synchronous bending. This type is made up of two torsion bar structures that are connected to the machine frame. They transmit motion via linkages and rocker arm to achieve synchronized movements of the upper die and lower die, and thus bend the workpiece. This is a mechanically forced synchronization. It is usually composed of a main motor with multiple clutches that transmit power to the tooling module.
What is CNC Press Brake?
We refer to an electron-hydraulic press brake as a CNC. The upper and lower modules are synchronized by combining hydraulic and electric systems in electro-hydraulic presses brakes. This system consists of hydraulic cylinders with servo valves and sensors. It also has a control system that uses electronic signals for precise control. Two side servo-valves are used to achieve synchronization. Sensors continuously monitor die positions while the servo motor transforms rotational movement into hydraulic power. It can adjust and monitor position deviations using sensors and feedback mechanisms in real-time, which ensures more accurate bending angle.
Most often, the electron-hydraulic press brakes are classified under CNC press brakes. The torsion bar series, however, are classified under NC press brakes. This article is primarily focused on clarifying the differences between the two types, as well as outlining the respective advantages and drawbacks of each type. It aims to answer potential questions from buyers.
Many customers in the manufacturing sector are confused when it comes to choosing between NC and CNC press brakes. Both machines serve the same purpose but have different capabilities and features. This article will shed light on the differences between the two types of presses brakes, from different perspectives. It can help both professionals and newcomers make the right decision.
Difference between CNC and NC Press Brake
Accuracy and repeatability
The accuracy of components like torsion bars, linkages, and transmission systems is heavily influenced by mechanical transmission systems. The elastic deformation of torsion bars and the adjustments of the adjustment rods can cause unsynchronized movements of the ram. This will affect the precision of the bending angle and flatness. These are ideal for bending applications, especially for smaller parts and those with low to medium precision requirements. Our NC Press Brake, however, is capable of +-0.01 accuracy, exceeding industry standards. It is a high-performance and cost-effective solution.
The CNC press brakes are controlled by a closed-loop system. This allows for high-precision synchronous bending. Electron-hydraulic control valves are used to ensure precise and synchronized tooling movement. CNC press brakes, on the other hand, offer greater precision in bending, with tolerances often as low as 0.01 millimeters, and they maintain stability after extended use. As a consequence, they are ideal for applications that require high precision, particularly in the production of complex workpieces.
Speed and efficiency
Due to mechanical limitations, the torsion NC system’s speed and responsiveness are comparatively slower. The torsion bar system takes some time to synchronize the upper and lower modules. This results in a relatively slow descending speed, but comparatively faster ascending and returning speeds. It may take more time to adjust and change the bending speed or perform complex multi-stage bends. It is usually fixed at a constant rate.
The CNC press brake (electro hydraulic), with its advanced electric servo and hydraulic control systems, offers a higher bending speed as well as greater production efficiency. This is because the system can quickly adjust the hydraulic cylinder movement speed and force through the electro hydraulic servo. It achieves faster work cycles and higher bending speed with precise electron-hydraulic controls.
Maintenance
The NC press brake adopts a simple mechanical system of synchronization, which results in lower maintenance costs. The simple structure of the NC press brake eliminates complex control systems. Regular inspections and lubrication are usually sufficient for critical components such as torsion bars. It is relatively inexpensive to replace its components.
The CNC press brake (electro-hydraulic), which involves complex hydraulic and electrical systems, incurs higher maintenance costs. It requires more maintenance. In addition to regular lubrication, inspections, and calibration of the key components to ensure proper function, it is necessary to maintain and calibrate the control system. Regular inspections are required of the electrical and hydraulic components. Its components are also expensive to replace.
Number of axes
NC press brakes (torsion bars synchronous) have three main axes:
The Y-axis controls the vertical movement and is responsible for the up and downward motion of the lower die during the bending operation. The Y axis controls vertical movement and is responsible for up and down movements of the lower die.
X-axis : This controls the horizontal position of the back gauge in order to align the workpiece. The X-axis controls backgauge movements, which allows for positioning the workpiece in the bending process.
The R-axis is the rotation axis of the backgauge. It allows the backgauge to be moved up and down in order to accommodate different bending requirements. The R-axis rotates the backgauge and allows the backgauge’s up and down movement to meet different bending needs.
The CNC press brake (electrohydraulic) has typically more axes, which provides greater flexibility and precision. A typical CNC pressbrake may have four or more main axes.
The Y1 and Y2 axes are independent control axes that allow the dual-action cylinder to move the top die (bending beam) up and down, ensuring uniform force distribution and parallel motion.
b. The X axis controls backgauge positioning and movement.
R-axis c. The R-axis controls depth adjustment for the back gauge.
The Z1-axis (Optional) and Z2-axis (Optional) control the forward or backward movement for the upper die, to suit different bending needs.
Crowning System
NC press brakes with torsion bar synchronous are usually not equipped with a crowning device due to their different working principles and pricing. CNC press brakes, with their advanced control system and programmability are priced higher and come with a crowning device to compensate for bending more precisely. Crowning systems improve the accuracy and quality of workpieces to meet the needs of complex components. The cost of the crowning system can be justified by its improved flexibility and capabilities.
Price Comparison
The CNC press brake (electrohydraulic), due to its more advanced and complex structure and control system is generally more expensive than the NC press brake. The NC press brake, on the other hand (torsion-bar synchronous), has a more simple system structure and operating principle. It typically uses basic mechanical or electric control systems. This results in lower costs. CNC press brakes require high-precision parts and advanced control systems. These increase production costs, and also demand more design and engineering expenses. The NC series may be more affordable in the short-term, but the CNC series will offer a higher return on investment.
Application Range
The CNC press brakes are ideal for applications that require high precision, efficiency and accuracy in bending. These are ideal for complex and large-scale workpieces. They are more expensive but offer a higher level of processing flexibility and quality. NC press brakes are ideal for general bending and are best suited to medium-to-small productions and simple workpieces.
Expandability
NC press brakes are limited in their expansion and cannot be easily integrated into other equipment to perform tandem operations or integrate robotics. CNC press brakes with electro-hydraulic technology are more expandable and can be used in tandem with other machines. They also integrate better with robots and other automation systems. Automation equipment will increase production efficiency, reduce labor costs, and eliminate production safety concerns.
Operator Skill Requirements
NC press brakes, also known as Torsion Bar Synchronous, rely on the skills of workers more than other types. This may lead to businesses paying higher salaries for more experienced workers. CNC press brakes are easier to operate and require less experience. They also have higher automation.
The conclusion of the article is:
Businesses should select the machine that best suits their needs. In the majority of scenarios, the NC press brake will be superior to the NC series. The CNC press brake will be a more cost-effective choice if the budget is available. In cases where budgets are limited, the NC Series can still meet some processing requirements. Please feel free to contact us if you have further questions. We will be happy to help you.
