Manufacturing > Wire EDM > Radius Substitution Tables
Radius Substitution Tables
Certain wire EDM machines are difficult to control when machining corners; as a result, parts are often overcut during initial passes that are created at a high power setting. Radius substitution allows you to modify selected reference part radii on a pass-by-pass basis, in order to achieve proper machining of the parts.
Radius substitution is performed by setting up radius substitution tables and associating them with 2-Axis Wire EDM NC sequences at the time of creating the Rough and Finish cut motions.
Radius substitution tables provide the value of the radius to be used in the toolpath generation depending on:
The type of the corner (concave or convex)
The value of the radius of the selected contour to be machined
The number of the pass (a Rough and up to 16 Finish)
When a table is used, the corner to be cut is evaluated to determine its type and the current pass. The toolpath for that pass is modified to have the radius from the table rather than that of the contour. The table is interpolated for contour radii not explicitly listed. Value of 0 (zero) means substituting a sharp corner for the radius. There is no interpolation between 0 and another substitution value. When a column has zeros in it, sharp corners are substituted for all values up to that where a non-zero substitution radius is listed. In the example below, sharp corners will be substituted on the Rough pass for all radii up to 0.007.