-Shenzhen Guanhong Automation Co.,Ltd.-
SZGH-CNC1000MDb Series
- 57 -
3.26 Tool Radius Compensation C (G40/G41/G42)
When the tool is moved, the tool path can be shifted by radius of the tool.
To make an offset as large as the radius of the tool, CNC firstly establish offset vector with a
length equal to the radius of the tool(start-up). The offset vector is perpendicular to tool path. The
tail of vector is on the workpiece side and the head position to the center of the tool.
If a linear interpolation or circular interpolation command is specified after start-up, the tool
path can be shifted by the length of the offset vector during machining.
To return the tool to the start position at end of machining, cancel the tool compensation mode.
Fig3.20.1 Outline of tool compensation C
Format: G41 T_ D_ ;
Tool radius compensation left
G42 T_ D_ ;
Tool radius compensation right
G40 ;
Cancel tool radius compensation.
T_ : tool radius offset number (T01~T99)
D_ : code for specifying as the cutter compensation mode.
At the beginning when power is applied the control is in the cancel mode. In the cancel mode,
the vector is always 0, and the tool center path coincides with the programmed path.
Start Up
: When a tool compensation command(G41 or G42, nonzero dimension words in the
offset plane, and D code other than D0) is specified in the offset cancel mode, the CNC enters the
offset mode. Moving the tool with this command is called start-up.
Specify positioning(G00) or linear interpolation (G01) for start-up. If circular interpolation
(G02, G03) is specified, cnc system will hint alarm.
When processing the start-up block and subsequent blocks,the CNC pre-read two blocks.
Offset mode
: In the offset mode, compensation is accomplished by positioning (G00), linear
Start
