The Machining Parameters options allow you to define various parameters related to cutting the part. The options described below are dependent on the Cut Type (External Trim, Internal Trim, No Core, Open Profile) specified. The following parameters can be customized.
This option allows you to define the amount of stock to be left after no core burnout and any finishes passes.
This value specifies how many rough passes will be made for Internal Trim, External Trim and Open Profile operations. Enter the desired number of passes or “0” for no passes.
This value specifies how many finish passes will be made after the roughing passes. Enter the desired number of passes or “0” for no passes.
This option allows you to define the length of material to be left as the backburn tab in an Internal Trim operation. Enter the value of the length.
This option allows you to define the length of material to be left as the cutoff tab in an External Trim operation. Enter the value of the length.
This option allows you to define the amount of stock to be left after the Cutoff operation. Enter the value of the stock.
This option allows you to generate a cutoff for each pass. If this option is toggled off you get a cutoff only on the last rough pass. You can also specify the order that the cutoff passes are generated in when multiple cutoff passes are made.
Region first specifies that each region has all of its cutoffs done before moving to another region.
Cutoff first specifies that the outermost cutoff in each region is completed first before going to the next pass.
This option allows you to define the diameter of the cutting wire. This option is available for all operations. There is no tool definition in Wire EDM. The wire is displayed from the lower plane to the upper plane. The only parameter required is the tool diameter. Enter the diameter value.
The Upper Plane and Lower Plane values are used to specify the two parallel planes in which the wire guide holders move. They define the upper and lower cutting limits of the wire and determine the length of wire that is displayed on the screen when using the 3-D tool display.
The position and orientation of the planes are relative to Machine Coordinate System (MCS). The planes are normal to the ZM axis and the values are measured from the MCS origin.
In the above figure, a Lower Plane value of -.25 positions the lower plane a distance of .25 below the MCS origin. An Upper Plane value of 1.50 positions the upper plane a distance of 1.50 above the MCS origin. The Lower Plane value must be less than the Upper Plane value.
The Upper Plane and Lower Plane values that you specify here are reflected in the SET/upper and SET/lower Post Commands.
The Upper Plane height is used by a postprocessor to define two things. It is used to define the Upper Plane in a single block, such as a G92 block. Or it can be used to define the location the upper wire guide needs to position to, in the coordinates of the upper plane. Typically the upper plane is UV and the lower plane is XY. The postprocessor uses the XY and I, J, K of the tool axis to calculate the UV position on the upper plane.
This option allows you to define a Stop Point for External Trim, Internal Trim, and Open Profile operations. A Stop Point temporarily stops the cutting process at a specified distance just before completing the last cut that will separate the part from the slug. This pause in the cutting process allows the machinist to perform manual operations such as repositioning the clamp. Once the machinist has completed these operations, the cutting process can continue.
For Open Profile and External Trim operations, the Stop Point occurs in the last pass at the specified distance from the end of the cut. For Internal Trim operations, the Stop Point occurs in the first pass at the specified distance from the end of the cut.Stop Point for Internal Trim Operation
The Stop Point toggle activates the Type and the Distance options described below.
Type may be set to one of the following:
Opstop (optional stop) creates a stop that is activated based on a set of conditions specified by the machinist. It allows the machinist to choose whether or not to utilize the Stop Point. For Internal Trim operations, if Rough Pass and Backburn are created as separate sub-operations, Opstop is applied to the Backburn operation. Similarly, for External Trim operations, if Cut Off is created as a separate sub-operation, Opstop is applied to the Cut Off operation.
Stop always utilizes the Stop Point. The machinist may not override this condition.
Distance is the length that will be left uncut when the Stop occurs. For External Trim operations, this stop point distance must be less than the specified Cutoff Distance (see the previous figure). Similarly, for Internal Trim operations, this stop point distance must be less than the specified Backburn Distance.
Stepover Parameters allows you to make multiple cutting passes at a specified offset.
When using On as the Wire Position, the processor will ignore the specified Stepover Parameters offsets.
Stepover Type may be set to one of the following:
Distance allows you to define a constant stepover as a specified distance. The stepover cannot be greater than the wire diameter. Enter a value for the length for Step Size.
Variable allows you to define a series of stepover distances for specified number of passes. The stepover cannot be greater than the wire diameter. You can enter the value for the distance of the Step Size and a value for the Number of Passes it will be applied to.
% Wire allows you to define a constant stepover as a specified percentage of the wire diameter. The stepover cannot be greater than the wire diameter. Enter a value for % Wire Diameter in the field.
Absolute Stock allows you to define each stepover as an absolute stock distance measured from the Part. A stepover (the difference between two consecutive stock offsets) cannot be greater than the wire diameter. The number of stock entries available in the Absolute Stock dialog is based on the number of specified rough and finish passes (total rough and finish passes minus one). The Stock values must be filled in progressively larger from top to bottom in the Absolute Stock dialog.
The Pass Cut Direction options allow you to specify the direction that the Wire EDM operation will cut the part. This option is available for Internal Trim and External Trim cut types.
Direction may be set to one of the following:
Alternate causes the Wire EDM operation to alternate between clockwise and counter-clockwise as it makes cutting passes along the tool path.
CW causes the Wire EDM operation to cut all passes in a clockwise direction along the tool path.
CCW causes the Wire EDM operation to cut all passes in a counter-clockwise direction along the tool path.
Tolerances allows you to set the global intol and outtol values for the tool path. These tolerance values can be set as part of a parameter set to be passed in or out of the operation.
Intol is the maximum allowable distance that the wire may deviate from the tool path into the part. Enter a value for Intol.
Outtol is the maximum allowable distance that the wire may deviate from the tool path away from the part. Enter a value for Outtol.