Fagor 8025 GP, Operating Manual

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8025/8030 CNC PROGRAMMING MANUAL 87
6.29. PROBES
6.29.1. Definition
Probes are basically simple switches provided with a high level of sensitivity.
When the probe touches a surface, a signal is sent to the CNC of the machine, and the
position of the axes are automatically recorded. In the case of machine tool applications,
this same signal acts on the control of the machine until an adequate, precise and rapid
positioning of the tool or part is obtained.
Probes do not measure, they simply send positioning signals to be treated in the CNC of
the machine and according to specific tolerances.
6.29.2. Characteristics
Probes are of modular construction for better adaptation to the needs of the user. This
system consists of a stylus, probe, transmission system and interface. The stylus is the part
which enters into contact with the surface.
They are provided with a system to absorb impact with the surface.
The tip of the probe includes the stylus.They are of solid and compact construction in order
to protect the stylus. Different extension modules can be fitted in order to obtain the right
geometrical configuration for each application.
Probes have three different systems:
- Cabling
- Inductive
- Optical
Cabling: The signal is transmitted through the cable. Its most important disadvantage is
its rigidness in moment. It is used in lathes and machining centers for final adjustments of
tools where the probe has a fixed measuring position and the tools are brought close to the
probes. It is also used in digitizing systems.
Inductive: It allows greater ease of movement. The signal is transmitted without physical
contact, by means of two opposing plates, across the work area.
Optical: Communication is made by means of infrared rays. One of its advantages is the
freedom to position the signal receiver outside the work area. Its applications are the same
as those of the inductive probe.