Constant Grinding Wheel Peripheral Speed (Gwps); Function - Siemens SINUMERIK 840D sl Function Manual

18.5

Constant grinding wheel peripheral speed (GWPS).

18.5.1

Function

For grinding wheels, generally the wheel peripheral speed is used instead of the spindle speed.
The value to be set is determined by technological process parameters (e.g. grinding wheel
characteristic, material combination).
To be able to specify the wheel peripheral speed in the part program, the tool-specific
parameters $TC_TPG1 (Page 848), $TC_TPG8 (Page 850) and $TC_TPG9 (Page 851) must
be set and the function "Constant grinding wheel peripheral speed (GWPS)" must be activated.
Note
Activation of GWPS does not cause the automatic activation of tool length compensation or
grinding-specific tool monitoring!
As soon as the function is active, any subsequent S value for the spindle that is assigned to
the grinding wheel via $TC_TPG1 will be interpreted as grinding wheel peripheral speed. The
grinding wheel speed is set such that, taking account of the current wheel radius, the grinding
wheel peripheral speed remains constant.
The formula for calculating the speed is as follows:
The correction value to be used for calculation is defined in the tool-specific parameter
$TC_TPG9. The associated wear and the base dimension as a function of the tool type are
added to this correction value. The sum total is divided by "cos" ($TC_TPG8) when the value
of parameter $TC_TPG8 (angle of inclined wheel) is positive, and is divided by "sin"
($TC_TPG8) when the value is negative.
The speed is recalculated in response to the following events:
● Specification a new grinding wheel peripheral speed, e.g. by:
– programming in the part program/overstoring
– assignment to the address "S" in MDI
– spindle speed control via PLC (FC18).
● Changing the online correction values (wear parameters)
Activation / deactivation
Activation/deactivation of GWPS is implemented by programming GWPSON(...)/GWPSOF(...)
in the part program (see "Programming (Page 871)").
Extended Functions
Function Manual, 10/2015, 6FC5397-1BP40-5BA3
W4: Grinding-specific tool offset and tool monitoring
18.5 Constant grinding wheel peripheral speed (GWPS).
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