Machine control advanced parameters
Pole handling
Generally, in a 5-axis machine, the tool axis vector can be mapped into two different angle pairs. There is only one exceptional case when the rotation is performed around a coordinate system axis (rotation axis), and the tool axis is parallel to the same rotation axis. In this case, any rotation angle value properly describes the tool position. Therefore, the rotation angle value can be arbitrary. Such tool axis orientation is referred to as «singularity» or «pole».
SolidCAM enables you to detect such pole areas and handle them with multiple methods:
Freeze Angle around Pole
In the pole areas, the arbitrary rotation angle is «frozen» when the tool axis orientation is parallel to the rotation axis.
Use Rotation Angle around Pole to stay within linear axis limits
If some areas of the tool path cannot be reached by the linear axes, this option can adjust the linear axes and use the rotation axes to substitute linear motions. For example, if you machine a cube on two opposite faces, left (-X) and right (+X), on a head-table machine, and machine limits do not allow -X movements, you can use this option to rotate the table axis to flip the cube.
Linear interpolation of Rotation Angle around Pole
In 5-axis machining, the tool can be vertical and any value of the rotary axis (usually C) can be used if the X- and Y-axis values are changed accordingly, i.e. the C-axis value can be chosen arbitrarily. The linear interpolation is distributed according to the number of intermediate points and their relative distance from each other.
Smooth interpolation of Rotation Angle around Pole
The smooth interpolation is similar to the linear interpolation, with the difference that the change of C-axis at first non-vertical position and second non-vertical position is performed smoothly.
Force table rotation available for pole handling strategies
This option is used on 4-axis table, 5-axis table-table and 5-axis head-table machines. In some particular cases of 4-axis tool path, when the orientations become closer to a 3-axis tool path, the post processor makes only translation/linear moves. This option is also suitable for mill-turn machines. Also, instead of moving the tool in XYZ, the Motion control can rotate the part, while the tool is fixed.
The Pole angle tolerance (degree) value defines the maximal angular deviation of the tool axis from the rotation axis to consider the tool axis parallel to the rotation axis.
Move list writer
Some CNC-Machine controllers have a limitation of acceptable angular coordinates. When an angular coordinate in the GCode exceeds such limitation, an error is returned by the controller. Almost all controllers have limitation from 0 to 360° or from -180° to 180°.
The Move list writer options enable you to define the angle limits for the output tool paths in order to generate a tool path compatible with the angular limits of the specific CNC-Machine controller.
The First rotation axis angle limit/Second rotation axis angle limit options enable you to define the angle limit of the first and rotational axes respectively.
- No limits- In this case there are no angle limitations of the output tool path. The angles can be in the range of -∞ to +∞.
- Limit between 0 and 360 deg- With this option, the angle coordinates in the output tool path are limited by the range from 0 to 360°.
- Limit between -180 and 180 deg- With this option, the angle coordinates in the output tool path are limited by the range from -180° to 180°.
Tool repositioning
These parameters enable you to control the angular tool movements in the calculated tool path.
Angle change
This parameter enables you to define the maximal angle variation between two successive tool positions. If the angle variation is greater than the specified value, a retract movement is added.
Retract distance
This value determines the distance of the retract movement that is performed when the angle change between two successive tool positions exceeds the Angle change value. For example, when the Angle change parameter is set to 100°, and the C-axis orientation at the first position is 10° and at the second position is 170°, SolidCAM considers such angle variation as inadmissible and performs a retract motion.
Retract tool to maximum
When the angle change between two successive tool positions exceeds the Angle change value, the retract movement can be performed to the maximal distance defined by the machine limit.
Retract&Rewind
This option is beneficial when the tool reaches one of the limits on rotational axis; it retracts to a safe area and a rotational back is performed to initial limit. You can set the rewind method by providing a value in the Angle field. A bigger value for angle step results in a rewind method in less moves.
When this option is disabled and the tool reaches the maximum limit, it executes a direct move back to the initial limit.
When this option is enabled and the tool reaches the maximum limit, it retracts to a safe area and a reverse rotation is executed to the initial limit.
Point interpolation
Interpolation type
The interpolation between two end points of the segment can be performed either in the shortest possible way or gradually, considering the machine kinematics. In the first case, you can choose the Linear interpolation of vectors option, and the motion between these vectors of the end point is in a flat plane. In the second case, you can choose the Linear interpolation of machine angles option, so the motion between two vectors of the end point is no longer in a flat plane.
The point interpolation provides the ability to create intermediate points by setting a certain maximum angle step distance (for 5-axis motions) or by splitting long linear motions (3-axis and 5-axis tool paths) for feed rate moves and rapid rate moves.
Interpolation angle step
Using this parameter, SolidCAM enables you to interpolate the angular movements. A new interpolated tool axis position is defined at each angle, defined by the Interpolation angle step parameter. For example, when the angular movement has to be performed from 10° to 22°, an Interpolation angle step value of 3° results in adding interpolated positions at 13°, 16° and 19°.
Interpolation for distance
Using this option, SolidCAM enables you to perform interpolation for the linear tool movements. When this option is active, a new interpolated tool position is defined at each distance, defined by the Interpolation for distance parameter. For example, when the linear tool movement is performed from 0, 0, 0 to 0, 0, 100 and the Interpolation for distance option is used with the Distance value of 10, SolidCAM adds 9 tool positions between start and end positions (0, 0, 10, then 0, 0, 20 etc.).
Rapid feed rate moves- When this option is selected, a new interpolated tool position is defined also for rapid moves.
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This option is available only when Interpolation for distance is selected. |
