What is Metal Turret Punching Fabrication?
A turret punch or turret press is a type of punch press used for metal forming by punching.
Punching and press work are especially suited for low to medium volume production runs. However the initial tooling costs, of both the machine and the job-specific press tool, are high. This limits punch work from being used for much small-volume and prototype work. A turret punch is one way of addressing this cost. The tooling of a turret punch uses a large number of standard punch tools: holes of varying sizes, straight edges, commonly-used notches or mounting holes. By using a large number of strokes, with several different tools in turn, a turret press may make a wide variety of parts without having to first make a specialised press tool for that task. This saves both time and money, allowing rapid prototyping or for low volume production to start without tooling delays.
CNC Turret Punch Operation & Process
With the turret affixed in position to make sure precise positioning, the program triggers the ram, driving the punch through the workpiece. After the punch is pulled back, the machine is ready to prepare for the next hit.
Some turret presses are assembled so that the crankshaft is used to both depress and disengage the tool. In this situation, urethane strippers surrounding the punch are used to hold down the workpiece throughout movement of the tool.
Regardless of construction, size or speed, all turret presses function in the same way. A sheet of workpiece component gripped at the edges by workholders, is moved across the table into position in between the upper and lower portions of the turret by motion of two precision lead screws (one in the X-axis, the other in the Y-axis). Meanwhile, the turret revolves until the necessary punch and die set in place.
Other machines are developed to disengage the tool by spring motion rather than with the ram. This needs a separate punch holder and allows for strippers of metal rather than urethane. Metal strippers can hold the workpiece more tightly, especially during forming operations.