Cnc Turret Punch Presses

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A CNC (computer numerical controlled) turret punch press can be a productive addition to your sheet metal fabrication shop. The basic punch press is a type of machine that is used to punch holes in metal, but the CNC turret punch press has many more capabilities than the basic punch press. CNC turret punch presses are use to manufacture parts like the control panel for an airplane - all those gages and switches are set in holes of different sizes and shapes punched in sheet metal using a CNC turret punch.

The great advantage to a CNC machine is that it can be programmed to produce a particular part, accurately over and over again without variation. It can produce parts far more quickly and far more accurately than could ever be accomplished with a manual machine.

One of the greatest speed advantages of the CNC turret punch press is the fact that many different tools (punches and dies) are mounted in the turret which can switch from tool to tool in less than a second. With a manual punch press the time required to change tools is many times that. The machine has an upper and lower turret with the upper turret holding ...
... the punches and the lower turret holding the dies. When a tool change is made, both turrets rotate simultaneously to the programmed position lining up the proper punch with the correct die.

The sheet metal to be processed in a CNC turret punch is laid down on a table and held at its long edge with hydraulic clamps. The machine has X and Y axis servos that move the sheet metal back and forth under the tools so that the all areas of the sheet of metal can be processed. If the sheet is wider than the X axis movement, most machines can unclasp and reposition the sheet of metal so as to cover, effectively, double the sheet size. This feature is called auto repositioning.

CNC turret punch presses can do more than just cut different shaped holes in a piece of sheet metal. They can also do forming and shearing. With the use of louver dies, three dimensional ventilating louvers can be cut into the sheet metal. Depressions, dimples or many other effects can be achieved with the proper dies.

Another great innovation was the invention of tool rotation in CNC turret punch presses. This feature allows the user to orient certain tools in any position, so, for example, if you wanted to make horizontal rectangular holes and vertical rectangular holes in the same part, if they are the same size holes you can do it with just one punch and die.

With computer control and hydraulic ram systems, both the velocity of the rams and their distance from the material can be controlled to a high degree of accuracy. This can save time by limiting the travel of the die up and down and can achieve interesting effects by slowing down the ram to allow deep drawing, which would be impossible with a regular mechanical punch.

The distance of the ram from the sheet metal (the hover height) is important, obviously, because if the ram is held at too short a distance from the material, it can hit the material if the material has any warps or dings in it. Fortunately, these days some automated systems take into account the entered width of the sheet metal, and for short distance movements, keep the rams as close as possible to the sheet metal - it is all automated. This type of efficiency can make a real difference in output, without requiring close guidance from personnel.

Some newer CNC turret punches have sheet loaders and stackers. These devices are wired into the machine control and effectively eliminate the need for an operator to feed material into the machine and take finished parts off the machine at the end of each cycle. With these devices, a machine can operate unattended for many hours which can allow one machine operator to handle many machines.

The latest CNC turret punches can be equipped with a secondary means of cutting the metal, such as a laser or plasma. The advantage of these machines is their ability to cut odd shapes without the requirement of making a custom (and very costly) punch and die.