# Fanuc Series 15i/150i-MA (Programming) Operators Manual

B-63324EN/03 PROGRAMMING 4.INTERPOLATION FUNCIONS
- 77 -
Limitation
- Overcutting during inner corner cutting
Theoretically, when the inner area of a corner is cut using linear
interpolation as shown in Fig. 4.10(m), this function slightly overcuts
the inner walls of the corner. This overcutting can be avoided by
specifying a value of R that is slightly greater than the radius of the tool
at the corner.
Fig.4.10 (m) Overcutting
- Setting the minimum input increment for an offset axis (Y-axis)
Set the same minimum input increment for an offset axis and linear axis
when cylindrical interpolation is performed.
When specifying the radius of a workpiece, use the minimum input
increment (with no decimal point) for the linear axis used in cylindrical
interpolation.
- Reference axis setting (parameter No. 1031)
If the increment system of a linear axis differs from that of a rotation
axis in cylindrical interpolation, set, as the reference axis, the axis
number of the linear axis for cylindrical interpolation.
Example
- Example of cylindrical interpolation cutting point compensation
The sample program below indicates the positional relationships
between a workpiece and tool.
O0001(CYLINDRICAL INTERPOLATION1) ;
N01 G00 G90 Z100.0 C0 ;
N02 G01 G91 G19 Z0 C0 ;
N03 G07.1 C57299 ;
N04 G01 G42 G90 Z120.0 D01 F250. ; - - - (1)
N05 C20.0 ; - - - (2)
N06 G02 Z110.0 C60.0 R10.0 ; - - - (3)
N07 G01 Z100.0 ; - - - (4)
N08 G03 Z60.0 C70.0 R40.0 ; - - - (5)
:
M30 ;
Tool
Tool
Overcut portion