Process

To ensure that the cycle is executed successfully, the following requirements must be met.

• The tool radius is defined by V.G.WZ_AKT.R
• Tool length compensation is active.
• The spindle speed must be selected before the cycle is started.
• The pocket centre can be reached without collision starting from the current position at the height of the retraction plane.
• A maximum of 3 systems may be active or defined when the cycle is called to ensure that sufficient machining coordinate systems (#CS) are available for the cycle.

Within the cycle, the tool is first fed incrementally along the Z axis. The starting point is a start point located above the pocket. The pocket is then milled from the inside out plane-by-plane and for every machining height in either a circular or helical movement. When the pocket is fully milled at the current machining height, the tool is retracted to the safety clearance in XY (@P13, relative) and Z (@P3, relative) at feedrate in a helical movement in a semicircle and repositioned back at the centre (XY plane) at rapid traverse. It is then positioned at feedrate at the next machining height.

Roughing process

At the start, the start point in the XY plane is approached at the height of the retraction plane for roughing. The infeed is first to the safety plane at rapid traverse along the Z axis followed by an infeed to the machining height at the feedrate defined by @P20. At this start point, an interative feed takes place up to the new machining height until the pocket depth @P4 is reached with the addition of the finishing allowance at the base (@P15). The maximum infeed per pass is the maximum infeed in Z at the maximum value defined in @P5.

At every machining height, the circular pocket is again milled from the centre outwards in a helical (@P34=1) or circular movement at infeed in a semicircle (@P34=2). The radius is obtained from the pocket radius (@P68) minus the finishing allowance at the edge (@P16). The clearance of the helical or circular path between each circumferential pass never exceeds the value of the maximum infeed in XY defined in @P6.

To avoid jerky movements in the milling path and thus relieve the machine tool, it may be useful to activate polynomial smoothing during roughing. This also leads to an accelerated execution of the milling cycle. The parameterisation of polynomial smoothing should be made dependent on the selected finishing allowance in order to avoid damage to the outer contour. To avoid residue, the maximum infeed in XY must then be reduced.

The milling cycle with polynomial smoothing can be called as follows:

#CONTOUR MODE [DEV, PATH_DEV = V.G.WZ_AKT.R / 10 ] ( Parameterisation )

G261                            ( Activation of polynomial contouring )

L CYCLE [NAME = SysMill... ]                               ( Roughing )

G260                          ( Deactivation of polynomial contouring )

L CYCLE [NAME = SysMill... ]                              ( Finishing )

M30

Finishing process

The start point mentioned for roughing is also approached as the starting position for finishing. From there, an interative feed takes place up to the new machining height until the spigot depth @P4 is reached. The maximum infeed per pass is the maximum infeed in Z at the maximum value defined in @P5.

A distinction is made between two cases for the milling operation at each machining height:

If no finishing allowance at the base needs to be removed at the current machining height, only the finishing allowance at the edge of the pocket is removed. If the current machining height also involves a removal of the finishing allowance at the base, the complete circular pocket must be again machined at this height until the correct dimensions are reached.