HPress brakes—they're wonderful machines that, unfortunately, in the operation of a CNC brake press, there are some very common mistakes can be avoided with a little diligence and awareness of where others have gone astray.The good news is that many mistakes are so common that a nice file of prevention tactics has stacked up against them.
The most common mistake that is made when operating a CNC press brake is not keeping it clean. Allowing dirt and grime to accumulate causes excessive wear to gibs and tooling. This can lead to problems with the electrical aspects of the machine or even cause a breakdown of the machine.
Machines and tooling should be wiped down every day before the first setup is made. Any oil residue should be removed to prevent shop dust from being attracted to the machine. The practice of keeping the machine clean prolongs the life of the machine and also makes setup faster and easier.
Another common mistake that happens is when it is upset of the ram. All press brakes are designed with a deflection limit under full tonnage loading. In this case, deflection refers to the tendency of the ram to bend upward in the center and the bed to bend downward under full tonnage loading. When the load is removed, the bed and ram return to normal stability.If the bending of the load becomes over deflected, this upsets the machine in the center. A larger angle is seen at this point and will require the bed of the CNC brake press to be fixed.This condition can be prevented by placing bending loads carefully and using only a sufficient amount of tonnage to make the part—provided you have adjustable tonnage capability on your machine.
The specifications of the part determine the tooling to be used, provided that the press brake is compatible with the tooling.
For example, for a bend radius larger than metal thickness and an angle tolerance between 1 and 2 degrees, you can air-bend with almost any brake that is in good condition. This type of bend requires the least bending load and helps to protect the brake from overload. However, if the radius is about equal to metal thickness, or the angle is close to 1/2 degree, you must bottom the part with four times the tonnage of air bending.
Even a CNC press brake machine with an accurate ram repeatability must bottom-bend for small inside radii. The secret is to understand fully the type of brake you have and use tooling that is compatible with that style of brake. Using the wrong style of tooling results in bad parts and possible damage to the brake.
If the hydraulic press brake for sale that is purchased is used on an unlevel surface, this becomes a problem. Ram gibs must be parallel so that the ram does not operate with a twisting motion. An out-of-level ram forms imperfect parts, and if the angle is bad enough, the gibs act as a brake, keeping the ram from returning to the top of stroke without increasing the return pressure.
There are types of hydraulic press brakes for you choice, different systems and different tons optional, from small types 30 ton -50 ton press brake to 400-1000 ton press brake.