Definition of feed axes

For the axes programmed in the command #FGROUP a path in space is determined, which is moved with the programmed feed. All other axes are treated like tracking axes. They reach their target positions at the same time like the path axes.

A characteristic feature of a path axis is, that the distance to be traversed is considered for the feed. In comparison the distance to be traversed of a tracking axis has no direct influence on the path velocity.

If no feed axes are programmed, the default settings of the channel parameters [1]-29/30 are valid.

#FGROUP  [ [<axis_name> {,<axis_name>} ] ] (modal)

<axis_name> Name of the axes, which are members of the feed group

For linear interpolation any axis may be feed axis, for circular interpolation and for polynomial interpolation following restrictions are valid:

• For circular interpolation either all main axes must be feed axes or all defined feed axes must be tracking axes
• For polynomial interpolation only main axes must be feed axes

Programming example

N10 #FGROUP [X, Y] (X and Y are feed axes) 
: 
N50 #FGROUP [A] (Tracking axis A is feed axis) 
: 
N100 #FGROUP (Feed axes according to the default settings)
(in the channel parameters) 
: 
N999 M3

During the processing of cylindrical workpieces on a rotary workpiece axis the real programmed feed [mm/min] shall be effective in the contact point of the tool. One way to ensure this, is the selection of a useful kinematic transformation (e.g. lateral surface transformation). The other way is the use of the NC command #FGROUP ROT[...]. After programming of this command the feed of the rotary axis (Grad/min) is transformed in dependence on a reference radius. When programming the rotary axis alone or together with linear axes, at the reference radius the demanded programmed feed arises.

#FGROUP ROT [ AX <axis_name> REF <reference_radius> ] (modal)

AX <axis_name> Name of the axis, on which the reference radius shall be effective.

REF<reference_radius> Effective radius of the rotary axis.

The deselection of feed calculation relating to a rotary axis is done with:

#FGROUP ROT (modal)

Typically this function is used für milling! Feed adaptations for turning are programmed via G95 and G96.

Programming example

Workpiece with reference radius R=10mm

N05 G00 C0 
N10 G01 C180 F1000 
(* Rotational speed of the workpiece 1000 degree/min *) 
(* Feed at the workpiece periphery 174.67 mm/min *) 
N20 #FGROUP ROT[AX=A REF=10] 
N30 G01 C360 F1000 
(* Feed at the workpiece periphery 1000 mm/min *) 
(* Rotational speed of the workpiece 5727.6 degree/min *) 
: 
Nxx #FGROUP ROT (Deselection) 

The command #FGROUP WAXIS defines independent from the default settings in the channel parameters that the axis with the longest running time („weakest axis“) is moved automatically as feed axis with the programmed feed (F-Word). All other axes are treated as tracking axes.

#FGROUP WAXIS (modal)

Programming example

N10 #FGROUP [X, Y] (X and Y are feed axes) 
: 
N50 #FGROUP WAXIS (Weakest axis is feed axis) 
: 
N100 #FGROUP [X, Y, Z] (X, Y and Z are feed axes) 
: 
N999 M30