The cylindrical interpolation is available in operations: 2D contouring, pocketing, 2.5D pocketing, 2.5D wall machining.
The cylindrical interpolation gives the possibility to mill the side surface of cylinder by programming the unrolled curves. The unrolled curves are programmed in the [X,Y,Z] coordinates, but the cylinder milling is performed in [X,C,Z] coordinates. So the cylindrical interpolation makes the transformation [X,Y,Z] => [X,C,Z].
The possibility to perform the milling of the side surface of cylinder depends on the machine construction.
If all listed condition are performed and the machine variable Machine –> Control parameters –> Rotary transformations –> Cylindrical interpolation is available is set then the rotary transformation panel will be available on the transformations page.
The <Mode> field defines the rotary transformation mode: none, polar or cylindrical transformation. The tolerance defines the deviation of the transformed tool path from the ideal one. It is measured in millimeters (inches).
The cylindrical transformation performs the next calculation
А – the position of the rotary axis in degrees,
Y – the position of the virtual unrolled axis that corresponds to the rotary axis,
R – the radius of the cylinder.
The corresponding fields defines the machine axes that are taken as the rotary axis, radial axis and etc. The default values for these parameters are defined in the machine schema.
The modern numerical controls have the possibility to perform the cylindrical transformation. So the described transformation is performed inside the control, not inside the CAM software. For such machines it is better to mark the <CNC interpolation> tick. In this case the G-code is generated in the [X,Y,Z] coordinates, and control makes the [X,Y,Z] => [X,C,Z] transformation. The G-code in the most cases looks like the next sequence:
The corresponding commands for the well known controls are shown in the table below.
If the machine variable Machine –> Control parameters –> Rotary transformations –> CNC support cylindrical interpolation is set then CNC interpolation tick is available. If this parameter is on then the G-code generated with the commands to switch on/off the cylindrical interpolation. Else the G-code is generated in the [X,C,Z] coordinates.
If <Allow rapid motions inside interpolation block> is checked then the interpolation switch on in the beginning of the tool path and switch off in the end of tool path. Else CNC interpolation is started before the work feed and closed before the rapid feed motion.