8 Press Brake Machine Mistakes and How to Avoid Them

Something metal fabricators like to avoid is an upset ram. No, that’s not a distraught male sheep wandering in from the farm next door, it’s a press brake machine problem. The ram is an integral part of the press brake, and to say it’s upset means it’s bent. It’s bad news when parts of your machinery get bent because that makes it hard to form quality parts.

Machines don’t have to be new to work well, but they do have to be cared for. Here’s a look at the importance of press brake maintenance.

Putting in straight bends

Sheet metal fabrications almost always go through the press brake. This is where we change it from sheet to a three dimensional shape. Those bends must be straight otherwise the final assembly won’t go together right.

In a poorly maintained press brake the bend follows a curved rather than a straight line. This is termed “canoeing.” It has several causes which all trace back to taking insufficient care of the machine. And that leads into the eight most common press brake mistakes.

1. Sticking gibs

Gibs in a press brake guide the ram and tool as it moves up and down. If there’s too much play the ram can twist and jam, much like the drawer in a chest. Gibs should be adjusted periodically to account for wear, and also need correct lubrication.

2. Neglecting lubrication

Lack of lubrication is another reason for the ram to stick, but all moving parts of the press brake will suffer if not lubricated. That leads to metal-on-metal contact which causes wear and reduces the force available for actually bending the metal.

3. Excessive or inappropriate lubrication

Almost as bad as not lubricating is slapping on too much grease, or the wrong type or putting it in the wrong place. Oil and grease attract and retain dust and metal fragments. These score sliding surfaces, accelerating wear and possibly causing seal leaks.

A well-maintained machine has just a film of oil, of the right viscosity, on the moving parts. When it’s too thick it increases drag and may not penetrate between components. Too thin and high loads can force it out, putting metal in contact with metal.

4. Wrong tooling

In this context what’s meant is setting up for a bottoming tool when what’s needed is air bending, or vice versa. Bottoming, when the top tool pushes the sheet down until it’s in contact with the bottom tool, takes a lot of force and puts a lot of load on the machine.

5. Not changing the hydraulic fluid

Most press brakes have complex hydraulic systems. Over time hydraulic fluid becomes contaminated with fragments dirt and possibly air and water. This limits what load the press can apply and reduces the lifespan of key components. Regular fluid changes are part of good press brake maintenance.

6. Machine not sitting flat

When any machine is installed it should be leveled. Floors can shift over time though, and that can twist a machine slightly. The result is increased wear and probably also bends that aren’t straight.

7. Poor housekeeping

We’ve already stressed the damage that dirt can do. A well-run shop ensures the machines are kept clean. It avoids quality problems, keeps the machines running better and extends their life.

8. Upsetting the ram

The ram can be upset when pressing forces are applied unevenly or the loads are too high. Uneven forces result if the metal being bent is positioned over at one side rather than in the center. And if the metal is too thick or not enough load is applied, that too can bend the ram.

An upset ram may be correctable by shimming the machine, in effect, distorting it back the other way. There’s a limit to how much is possible though. In cases where the ram is severely upset the press brake may need a complete rebuild. Alternatively, it might be time to call Animal Control.