W1: Tool offset
18.10 Special handling of tool compensations
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
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18.10.8 Tool length offsets in tool direction
Temperature compensation in real time
On 5axis machines with a moving tool, temperature fluctuations can occur in the machining heads. These can
result directly in expansion fluctuations, which are transmitted to the tool spindle in the form of linear expansion.
A typical case on 5axis heads, for example, is thermal expansion in the direction of the longitudinal spindle axis.
It is possible to compensate this thermal expansion even when the tool is orientated by assigning the
temperature compensation values to the tool rather than to the machine axes. In this way, linear expansion
fluctuations can be compensated even when the tool orientation changes.
Using the orientation transformation whose direction is determined by the current tool orientation, it is possible to
overlay motions in real time and rotate them simultaneously. At the same time, the compensation values are
adjusted continuously in the tool coordinate system.
Compensation applies to the "Temperature compensation" option and is active only when the axis to be
compensated is really referenced.
Activation
Temperature compensation in the tool direction is an option, which must be enabled beforehand.
It is activated by setting the following machine data to a value other than zero.
MD20390 $MC_TOOL_TEMP_COMP_ON (Activation of temperature compensation for tool length)
In addition, the bit 2 must be set for each affected channel axis in the machine data:
MD32750 $MA_TEMP_COMP_TYPE [<axis index>] (temperature compensation type)
This can be more than three axes in cases where more than three channel axes in succession can be temporarily
assigned to geometry axes as a result of geometry axis replacement of transformation switchover. If this bit is not
set for a particular channel axis, the compensation value cannot be applied in the axis. This does not have any
effect on other axes. In this case, an alarm is not output.
Applicability
Temperature compensation in the tool direction is operative only with generic 5axis transformations with:
• Transformation type 24
Two axes rotate the tool
• Transformation type 56
One axis rotates the tool, the other axis rotates the workpiece without temperature compensation
In generic 5axis transformation with:
• Transformation type 40
The tool orientation is constant with a rotary workpiece, which means that the movement of the rotary axes on
the machine does not affect the temperature compensation direction.
Temperature compensation in the tool direction also works in conjunction with orientation transformations (not
generic 5axis transformations) with:
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