The never-ending ebb and flow of the manufacturing environment presents sheet metal fabricators with an endless list of high-risk challenges. In strong economies, they often struggle with how to increase manufacturing capacity to meet customer demands. This requires fabricators to analyze the capacity of existing machinery and labor, the availability of additional hours to run existing machinery, the availability of skilled labor, and when there are no other options, the need to purchase new machinery.
Of course, the purchase of new machinery in and of itself comes with a new set of challenges. These include the availability of the machinery, which in a strong economy almost always come with long lead times, the floor space required to install it, once again the availability of skilled labor to run it, the affect on the flow of materials through the shop, and more recently, in some municipalities, the availability of power to run it.
When downturns in the economy come as they eventually do, one solution for fabricators is to cut back on the hours that they run existing equipment. However, shutting down machinery and having to reassign or, worst-case scenario, let go of skilled operators is a very unpleasant proposition. Needless to say, any solutions that can help maximize productivity during strong economic cycles and minimize risk exposure during weak economic cycles can be invaluable.
One option that deserves serious consideration and yet is often overlooked is to retrofit newer more advanced features and technologies to existing machinery. One excellent candidate is the press brake, which is vital to the manufacturing output of the overwhelming majority of sheet metal shops. Fortunately, for most press brakes, even older ones, a long list of options are available to improve the setup times, accuracy, flexibility, finished part quality, assembly times and operator safety.
Making changes
Let’s examine some of the possible ways where retrofitting can apply to press brakes. The first, and easiest, is to simply replace older, worn out or less accurate tooling with higher quality precision ground and hardened tooling. This option presents the press brake owner with the ability to purchase tooling one punch and die at a time as their budget allows or to purchase a new tooling package that is capable of bending most or all of the materials that they form.
Another option for retrofitting is the back gauge. Back gauges take a pounding in day-to-day use as operators in a hurry to get parts off the press brake and out the door slam sheet after sheet of material into them one bend at a time. Understandably, as the materials become thicker, heavier and harder, the damage to the back gauge accelerates. This often includes wear to the front face of the gauge fingers and on the drive mechanisms and affects the ability of the back gauge to create bend lines that are parallel with the tooling.
Of course, retrofitting a new back gauge to the press brake almost always calls into question the control. Does it provide an adequate number of axes? Can it be programmed offline? Does it come with a tooling library and, if so, how easy is it to import tooling files for both standard tooling and any special tooling? And, of course, how easy is it to teach the press brake operators to be able to program it and run it?
One way to get the best utilization out of a new control, and a press brake in general, is to add offline programming software. For a large percentage of sheet metal shops, it no longer makes sense to have their press brake operators programing at the machine. While offline programming software can represent a significant investment, the payback in additional productive time on one or multiple press brakes and the number of finished parts out the door can be huge.
Other options include hydraulic and pneumatic punch clamping systems. These clamping systems seat, center and align punches with the push of a single button. They are available for the most common styles of tooling and come with a variety of productivity enhancing features such as hardened working surfaces, cover strips with scales on the front, manual alignment along the “TX” axis, guards on the ends and even a series of lights to indicate tool location during setup and part location during each step of bending.
The crowning
Finally, for those fabricators that are bending parts typically 8 ft. to 10 ft. (2.5 m to 3 m) or longer, the odds are good that if the press brake isn’t equipped with a crowning system, the operators are struggling with parts that are open in the center and possibly over-bent on the ends. Frequently referred to as the “canoe effect,” this invariably leads to the need for operators to shim the dies being used to correct the problem. This adds a considerable amount of time and cost to their setups.
Even worse, die shimming is akin to an art form and is very difficult for a skilled press brake operator to teach. Any company that has the misfortune of losing an experienced operator can count on setup times increasing due to the additional time required to shim the dies by less experienced operators.
Fortunately, a variety of crowning systems with a broad range of features are available for virtually every press brake and every bending application that can eliminate the problem. For shorter press brakes where a crowning system is unnecessary, it is possible to equip them with bottom tool holders that are equipped with manual alignment along the TX and TY axes to provide extreme accuracy, which is often required in the short-run precision, prototype and model shops where these machines are frequently in use.
The good news is that all of the retrofit solutions mentioned are available from multiple suppliers for virtually every press brake make and model ever produced.
