Approach function APPR PCT
Application
With the NC function APPR PCT, the control approaches the contour on a circular path tangential to the first contour element.
Coordinates of the first contour point are programmed with polar coordinates.
Related topics
- APPR CT with Cartesian coordinates
Requirement
- Pole CC
You must define a pole CC before programming with polar coordinates.
Description of function
This NC function encompasses the following steps:
- A straight line from the starting point PS to the auxiliary point PH
The distance of the auxiliary point PH to the first contour point PA arises from the center angle CCA and the radius R.
- A circular path from the auxiliary point PH to the first contour point PA
The circular path is defined by the center angle CCA and the radius R.
The direction of rotation of the circular path depends on the active radius compensation and the algebraic sign of the radius R.
The table shows the relationship between tool radius compensation and the algebraic sign of the radius R and the direction or rotation:
Radius compensation | Algebraic sign of radius | Direction of rotation |
---|---|---|
RL | Positive | Counterclockwise |
RL | Negative | Clockwise |
RR | Positive | Clockwise |
RR | Negative | Counterclockwise |
If you change the algebraic sign of the radius R, then the position of the auxiliary point PH changes.
The following applies regarding the center angle CCA:
- Only positive input values
- Maximum input value 360°
Input
11 APPR PCT PR+15 PA-90 CCA180 R+10 RL F300 | ; Approach the contour on a tangential circular path |
To navigate to this function:
Insert NC function All functions Path contour APPR APPR PCT
The NC function includes the following syntax elements:
Syntax element | Meaning |
---|---|
APPR PCT | Syntax initiator for a circular approach function tangential to the contour |
PR | Polar coordinate radius Entry: absolute or incremental Optional syntax element |
PA | Polar coordinate angle Entry: absolute or incremental Optional syntax element |
CCA | Center angle as a fixed or variable number Entry: absolute or incremental Optional syntax element |
R | Radius as a fixed or variable number Optional syntax element |
R0, RL, RR | |
F, FMAX, FZ, FU, FAUTO | |
M |
Note
The Form column allows toggling between the syntaxes for Cartesian and polar coordinate input.
Example APPR PCT
11 L X+5 Y+10 R0 F300 M3 | ; Approach PS with R0 |
12 CC X+50 Y+20 | ; Set the pole |
13 APPR PCT PR+30 PA+180 CCA40 R+20 RL F300 | ; Approach PA with CCA40 and RL; distance PH to PA: R+20 |
14 LP PR+30 PA+125 | ; Complete the first contour element |