The Clearance plane is a cylinder defined along the axis of rotation wherein all transfer motions between a retract and engage motion takes place. Typically you would define this plane at a certain safety distance above the part geometry. This is done to prevent the tool from touching the part being machined during transfer motions since these motions usually use a very fast or rapid feed rate.
Refer to the following parameters:
 Dialog Box: Clearance tab, similar for 4 Axis Milling Operations |
The following options are available for defining the clearance cylinder: Automatic Allow the system to calculate a the clearance plane height automatically based on the part and stock geometry.  Automatic Part Max R + Dist Select this option to use the part's Maximum Radius (R) height and then enter a Distance value to add to this for the total R height for the Clearance Cylinder.  Part Max R + Dist Stock Max R + Dist Select this option to use the Maximum Radius (R) height of the Stock plus the specified Distance for total Radius of the Clearance Cylinder. If stock geometry does not exist, the Maximum radius of the Part geometry is used.  Stock Max R + Dist Absolute Z Value Select this option and then specify the absolute clearance radius (R) to use. Be sure that the value you specify clears your part geometry.  Absolute R Value Ignore Wireframe Geometry in Bounds Computation Check this box to ignore all wireframe geometry when calculating the Clearance Plane definition. When checked, the Automatic and Part Max options for defining the Clearance will be calculated from actual surface geometry. |
You can also control the transfer motions during cutting. When the cutter has finished cutting in one region and needs to transfer to another region to begin cutting, or it could do a skim motion. Skim Select this option to perform a Skim motion. The system automatically determines the safe Skim Cylinder height by taking into consideration the condition of the part and stock model. An additional Skim Clearance can be specified and will be added to the computed (R) value as the height to perform the Transfer Motions.  Skim Clearance (C) Clearance Cylinder Select this option to move the tool to the Clearance Cylinder and then perform the Transfer motion to the next cut location.  Clearance Cylinder |