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sheet metal machinery

Influence of sheet format on the punching machine

The sheet format to be punched is one of the factors that can influence the quality of the piece machined in a punching machine. If the sheet format introduced in the punching machine is the same size as the part, the following effects could be encountered:

· Problems with the sheet metal length: the part’s size is not exact, due to the accuracy problems most of the manual shears have. Consequently, the theoretical value of the length is, for instance, 1 mm less that the real one. The resulting effect is that a 1 mm strip is left uncut. In order to avoid this, the cutting program must be set so that the punch overlaps the metal by 1 mm.

· Squaring errors: A squaring error on the format to be punched may mean faulty measurements taken on the format relating to the outline of the metal. To ensure perfect squaring on different cuts in the sheet metal, the outer cuts should be made on the punching machine.

· Shaping in an “arrow”: This effect can cause the sheet metal to move when repositioning because it is being pushed by the clamps. This effect can be partially avoided. When the clamps are opened during repositioning, the machine is made to go back a value (2mm), and once the repositioning has been made, the forward movement is less than the backward (1mm), with the program compensating the difference between the backward and forward movements. This allows compensation for errors up to 1 mm.

Following these helpful tips, you will avoid punching errors. In DANOBAT we will advise for your punching machine programming and resolve all of your doubts in this regard.


Practices to avoid when programming a punching machine

A proper programming is vital to the proper functioning of any machine, and of course of a CNC controlled punching machine. Programming directly affects the productivity of the machine as well as the life of its components and tools, so with better programming the punching machine will become more productive at lower cost.

In order to make proper programming of a punching machine is necessary to follow some guidelines and criteria, and at the same time to avoid some practices that may cause operating problems. Some of these practices are the following:

Use the largest possible tools: if we use large tools with the idea of reducing the amount of punches and so try to minimize punching time, we may make the mistake that those tools do not work correctly, which will cause premature tool wear and this misuse will generate problems.

Large size micro-fastenings on the sides of the part: using larger micro-fastenings with the intention of reducing the number of micro-fastenings is wrong. It is more interesting to place more and smaller micro-fastenings, which facilitate the separation and removal of the parts .

Loose scraps: it is very important to avoid loose scraps on the table, since if any of these remnants is placed just at the punching point, the thickness will be double and then the gap will not be accurate.


Laser cutting

The birth of the first laser dates back to 1960, and in little more than 50 years, the evolution of the laser in the industry has been very quick, so much that its use in some processes is already widely consolidated, as in the case of sheet metal cutting. The application of sheet metal laser cutting solves manufacturing problems of complicated parts that could not be performed otherwise.

Laser technology is a field that offers endless possibilities, whose full potential has not been discovered yet, even through the important developments made recently, as it is the appearance of the fiber laser, whose main advantages were explained in a previous post.


Influence of programming on the life of punching tools

Correct programming of a punching machine affects directly the life of its punching tools. The number of punches a tool can make in a punching machine is closely related to the programming of the same. Poor programming can greatly reduce the life of the punching tools.

When making a program, you must take into account that the tool should work at least to 2/3 of his section, in order to avoid as much as possible the decompensation of the punch, and prolong considerable the life of the tool.

In the event that alternate punches must be programmed, which are mainly used for thick sheet metal punching, machining of the slots must be performed in two operatons, so one in every two punches is left undone. This results in centred and balanced punches, so that the force used on either side is the same, which avoids tool wear.

Following these helpful tips, the life of the tooling of your punching machine will be extended, with the consequent economic saving this entails. In DANOBAT we can supply all kind of punching tools, in addition to solve all your doubts in this regard.