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 contour pocket can be reached without collision starting from the current position at the height of the retraction plane.
• The contours used were already programmed using #CONTOUR BEGIN / #CONTOUR END.
• The defined contours for pocket and islands are closed, i.e. start and end points are identical.

Within the cycle, the tool is incrementally fed helically or vertically along the Z axis. The starting point is a start point located above the contour pocket. For a helical plunge, the system checks whether the defined radius of the plunging helix leads to a contour violation.

The pocket is then milled out again parallel to the contour at each machining height. When the pocket is fully milled at the current machining height, the tool is retracted at feedrate in a helical movement in a semicircle in XY (maximum infeed in XY, relative) and Z (@P3, relative) and repositioned at the matching plunge point at rapid traverse. It is then positioned at feedrate at the next machining height.

If individual contour elements were specified at a feedrate during the contour definition, it is activated for the particular element during edge finishing.

When complex contours are milled, there may be milling movements containing no material removal. If the length of an empty section exceeds a certain value, the cycle will attempt internally to lift the cutter at certain points and replunge at a position that has already been removed.

Roughing process

When roughing, the contour pocket is milled out again parallel to the contour at each machining height. The specified finishing allowance is added to the edge and base of the contour.

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 contour 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 deviation from the calculated milling path (PATH_DEV) must not exceed the tool radius.

The contour milling cycle with polynomial contouring can be called as follows:

#CONTOUR MODE [DEV, PATH_DEV = V.G.WZ_AKT.R / 2]    ( Parameterisation )

G261                             ( Activation of polynomial contouring )

L CYCLE [NAME = SysMillContourPocket.ecy @P31 = 1, @P... ]  ( Roughing )

G260                           ( Deactivation of polynomial contouring )

L CYCLE [NAME = SysMillContourPocket.ecy @P31 = 2, @P... ] ( Finishing )

M30

Finishing process

When finishing the contour pocket, the maximum infeed in Z is also iteratively fed at the new machining height until the pocket depth is reached.

A distinction can be made between two cases for the milling process during finishing:

• 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 contour (island) is removed. The milling cutter is fed slightly offset to the edge of the contour to ensure a faster plunge.
• If the current machining height also involves a removal of the finishing allowance at the base, the complete contour pocket must be again machined at this height until the correct dimensions are reached. The cutter is lowered above the calculated plunge position for this purpose.