Some press brake owners are in a dilemma about what to do when they no longer need their press brakes.The dilemma is between installing and selling the old press brake or moving it. It can cost thousands of dollars to replace it, and there may be logistical problems.

Retrofitting an existing press brake with features to reduce setup time and operator fatigue can be a cost-effective way to increase productivity.

You can decide whether an upgrade is worthwhile or not by knowing which retrofits exist and which ones are best suited for your machine. These five steps can help you determine your next step.

1. Assess the machine's hydraulic, mechanical, and electrical condition

Most important are:

Ram Accuracy. Does the ram level, accurate and consistent on both sides? Your press brake's accuracy may depend on the bending method you use. Are you coining, bottom bending, or air bending? It may be difficult to justify replacing a press brake if your bending method produces accurate results. Retrofitting your press brake may be a more cost-effective option than replacing it.

Foot pedal or pedestal control? Do you have a working foot pedal or pedestal control? These components may be considered obsolete by some press brake OEMs, or the programmable boards could be difficult to locate. It is important to research the availability of these parts before investing in a retrofit. Some retrofits of control systems require that these components are in good working order, while other retrofits may use replacement boards that closely mimic the OEM logic boards.

Backgauge. Is your press brake's backgauge control faulty and in desperate need of replacement? Reusing the mechanical structure of the press brake's backgauge while replacing the control (see the Lead image) is one way to increase the productivity. The backgauge control on many older machines is nearing its end of life.

Control for Press Brake. Is the entire functionality of the press-brake controlled by the programmable head? This control is necessary to operate the press brake, or can the machine be operated manually without it? Retrofit options will be more complex and expensive if the signals sent by the control of the press brake are required for the brakes to work. Retrofit options are more expensive and complex if the brake cannot be operated manually.

2. Know what you're working with

Mechanical press brake: A stand-alone CNC Backgauge System can be added, but the ram programmability is not an option. (See Figure 1.). Mechanical press brakes have a high degree of accuracy, as the tonnage is derived from the rotation around the bottom dead center (BDC). The machine is capable of producing a high amount of tonnage when it is at the bottom stroke.

The downside of this is that the ram cannot be programmed. It is therefore not possible to sequence through different bend angles, as it is with a hydraulic press brake. In coining operations, mechanical press brakes are commonly used.

Hydraulic Press Brake: The traditional rocker style press brake, which was popularized in the 1980s & 1990s, is a great example of a retrofit table hydraulic pressing brake. These machines use mechanical links to increase the force and maintain accuracy. They have a repeatability for the ram of typically +- 0.002 inches. Third-party retrofitting companies can usually interface their controls because they use limit switches, transducers and hydraulics to regulate the force and position of the ram.

There are also hydraulic brakes that use torque tube style, depth stop style and hydra mechanical.

Proportional Valves/Synchronized Style (Y1,Y2). These hydraulic press breaks have high accuracy and repeatability. These hydraulic press brakes are ideal for air bending, with precision-ground tools.

These machines are equipped with sophisticated controls (often PC-based) because they require "brains" to communicate with proportional or servo vales. The hydraulics are constantly regulated on both sides of the machine in order to maintain accuracy and level ram.

Retrofit controls are often PC-based and offer a variety of features to maximize the productivity of precision press brakes.

Most commonly, air bending tooling is precision-ground. Retrofit controls are available for these machines and offer a complete tool library, as well as a graphical simulation. Retrofitting controls can be costly because they offer more control and require a closer integration with the press.

3. Assess your pain points

Backgauging or Frontgauging. What makes more sense: backgauging, or frontgauging. Backgauging and frontgauging are determined by the dimensions that matter most.

Front gauging is the best option, for example, when you are making a two-bend, simple part, with flanges on both ends, but the bend-tobend dimensions are more important. By using a front gauge, you can maintain the critical tolerance at the center, and push any variances to the flanges. The flange measurements are most accurate when back gauging.

Tool Changes. Do you frequently change your tools? If you are, do your die heights change? You'll need to adjust the height of the gauging surface and fingers often if you have to change the tooling. An R axis combined with a backgauge may prove more efficient. You can program the R axis to adjust the gauge surface height for each bend.

Depth/Angles. How often do you manually adjust the ram angle or depth? You can increase productivity if you add the ram axis (or Y axis) to the backgauge/frontgauge systems (see figure 2). Angles can vary even within the same piece. Add a Y-axis to the press brake to allow you to change the depth and angle of the ram to fit each bend.

4.Decide on the Appropriate Approach

Size Backgauge System. Most retrofit companies require the length of the press braking or the distance between side frames. Also, they would like to learn a bit about your application. Do you bend light-gauge metal sheet or heavy plate? Are there multiple operators or just one?

Control capabilities. Most retrofit companies offer a variety of controls for different applications. These controls can be very basic, such as a position control that is used by job shops to make one-off components, or multiaxis controls with some job storage. They can also range from PC-based controls with networking, off-line programming and unlimited storage to more complex ones.

5.Use a solution

You have three options if your press brake works properly, but you still want to increase the productivity of your bending. You can:

• You can leave the machine in its current state at no extra cost.
• Buy a new multiaxis presses brake.
• Retrofitting a backgauge or the controls is possible.

Retrofitting your press brake can save you a lot of money if it is working properly with the factory settings and parts. Press brakes can have a single-axis retrofitted for less than $10,000. You can expect to spend between $5,000 and 7,000 dollars per additional axis in the system.

The control-only retrofits can also be an effective way to regain the productivity of your presses brake. This is provided that the backgauge controls are the cause of the problem and that the mechanical components of the backgauge remain sound. These retrofits are only for the control. They can be used to interface with the ram, back gauge and other axes in the system. The drives are usually replaceable at an extra cost.

You can expect to spend anywhere between $10,000 and $25,000 on a retrofit that only involves the control system, depending on your system's complexity. Regardless, this cost still is likely to be significantly less than purchasing a brand-new press brake as long as your existing machine is working properly--mechanically, electrically, and hydraulically.

It is important to calculate the cost of repairing your press brake before contacting a retrofitting company to estimate how much an upgrade will cost.

You may decide that it is better to replace the machine after doing thorough research. There are many great options available if that is the case. The newest technology trend is servo-electric-driven press brakes. These brakes require little maintenance, do not use hydraulic fluids or pumps, and are repeatable and accurate to 0.00008 inches. They also consume less energy.