NCT Group 99M, 2000M manual O7500POLAR Coordinate Interpolation

4.6Polar Coordinate Interpolation (G12.1, G13.1)

The diagram beside shows the cases when straight lines parallel to axis X (1, 2, 3, 4) are programmed. )x move belongs to the programmed feed within a time unit. Different angular moves (n1, n2, n3, n4) belong to )x move for each straight lines (1, 2, 3, 4). Apparently, the closer the machining gets to the origin the larger angular movement the rotary axis has to make within a time unit in order to keep the programmed feed.

In case the angular move to be made within a time unit exceeds the value of parameter FEEDMAX set for rotary axis the control gradually decreases the tangential feed.

With these in mind, programs in case of which the tool center moves close to the origin are to be avoided.

Fig. 4.6-2

Example

Below an example for the use of polar coordinate interpolation is shown. The axes taking part in the interpolation: Axes X (linear axis) and C (rotary axis). Axis X is programmed in diameter, while that of axis C is in radius.

Fig. 4.6-3

%O7500(POLAR COORDINATE INTERPOLATION)

...
N050	T808
N060	G59	(start position of coordinate system G59 in

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