HEIDENHAIN CNC Pilot 4290 - Manual (Page 22)

1 Introduction and Fundamentals 10
1.5 Tool Dimensions
The CNC PILOT requires information on the specific tools for a variety
of tasks, such as calculating the cutting radius compensation or the
proportioning of cuts.
Tool length
All position values that are programmed and displayed are referenced
to the distance between the tool tip and workpiece zero point. Since
the control only knows the absolute position of the tool carrier (slide),
it needs the dimensions XE and ZE to calculate and display the
position of the tool tip. For milling and drilling tools operating with the Y-
axis, the CNC PILOT additionally needs the dimension in Y.
Tool compensation
The tool tip is subjected to wear during machining processes. To
compensate for this wear, the CNC PILOT uses compensation values.
The system automatically adds the compensation values to the
values for length.
1
.5
T
ool
Dimensions
Tooth and cutter radius compensation (TRC)
The tip of a lathe tool has a certain radius. When machining tapers,
chamfers and radii, this results in inaccuracies which the CNC PILOT
compensates with its cutting radius compensation function.
Programmed paths of traverse are referenced to the theoretical tool
tip S. The TRC function compensates for this error by calculating a
new path of traverse, the equidistant line.
Milling cutter radius compensation (MRC)
In milling operations, the outside diameter of the milling cutter
determines the contour. When the MRC function is not active, the
system defines the center of the cutter as reference point for the
paths of traverse. The MRC function compensates for this error by
calculating a new path of traverse, the equidistant line.