To wrap up our Design for Manufacturing series, SigmaNEST consulted with Matt Calkins, Senior Application Engineer, to discuss three key design considerations when using a press brake.
1. Internal radii
The first important consideration is the internal radii. In most cases, it is safe to model the part with the Ri = t. Since air bending has become a standard practice, it can be challenging to achieve the exact Ri that the part was originally modeled with. Typically, it is safe to choose a die with an opening between 6 to 12 times t when Ri = t. Most designers have their own rules for selecting the correct punch & die combination to form a part but 6 to 12 times is a good rule of thumb if you are unsure. Not all shops have a large selection of punch and die combinations to choose from, so the Ri will most likely vary from the exact Ri the part was modeled with. Programs like SigmaBEND allow the engineer or programmer to run the model through the tooling and then the software will make the proper adjustments to the flat so that the flange lengths will not be compromised.
2. Accuracy in the calculations
A second important factor to consider is the accuracy in the calculation of the k-factor, bend deduction and bend compensation. With an accurate print, an exact model of the part can be created. Once put into production, the model must start as a flat pattern. Accuracy in k-factor, bend deduction and bend compensation is crucial. Like most processes in the fabrication industry, each production shop will have their own calculation methods. One challenge to consider is the likelihood of variations in the thickness of material gauge. Depending on the material composition and the process in which the coil was leveled, the way the material reacts to forming will always vary slightly. Unfortunately, it is an unavoidable part of the process.
3. Selecting the right machine for the job
There are many factors to consider when forming parts on a press brake, however, the machine itself should not be overlooked. Although it comes infrequently, selecting a machine is an important decision. Consider what parts are going to be formed using the machine. Big parts require a big press brake while smaller parts won’t require something as large. Real estate is always at a premium in a production environment as well. Advancements in technology make press brake capabilities almost limitless. While the need for a larger press brake may be inevitable, newer technology on smaller press brakes enables them to do more. But, always do your homework before making the purchase. Like anything else in life, you get what you pay for. There are plenty of used press brakes on the market but you can’t always accurately estimate the safety of older machines. Humans are the number one resource for any company, so safety should always be a priority over cost.
From design to production SigmaNEST wants to help you make the most of your press brake machines. SigmaNEST’s bending software, SigmaBEND, maximizes the speed, quality and flexibility of bending processes with full 3-D simulation. SigmaBEND supports different bending processes like air bending, die bending and 3-point bending.
Schedule a demo today to learn more about SigmaBEND and its capabilities.