As the interactive link between computer systems and industrial machinery continue to grow, two companies with an interest in both sides of the link—EDM and machining center maker Makino and software specialist EDS—have decided to share some basic tips on evaluating CAD/CAM programs.

Associativity is an important attribute, since it helps shorten lead times. If there are mold component libraries, you can likely draw on this past experience for another project rather than reinventing the wheel. Flexibility should also be examined in a program in terms of its ability to import data—imported data might be incomplete or imperfect for any number of reasons—so check to see if the program can analyze the validity of imported geometry. A good software package will look for misaligned objects, self-intersection, and spikes and cuts on faces, and check for edge smoothness and other tolerances.

You might also want to ensure the program can repair, complete and improve imported models. For example, the software should:

• Contain and work with multiple bodies or nonjoined surfaces in a single file
• Move individual faces on an imported model
• Realign edges of mismatched surfaces
• Arrange surfaces into solids
• Perform Boolean operations and trim bodies

There are also other helpful modeling capabilities. Modeling can have a positive impact on electrode design, mold parting line design, and large mold assemblies. Electrode design for EDM machining requires spark gap modeling. This requires the ability to move and/or offset faces, depending on the orbiting pattern.

You might want to ensure that your software can move and offset individual faces, trim, untrim, enlarge and extend surfaces, remove blends from imported models, and heal the adjacent surfaces. A software package should also achieve proper electrode offsets through advanced modeling when close tolerances and checking prints are required. When the requirements are less stringent, CNC programs can compensate with material offsetting. The automation of mold parting and large plastic molds assembly can also impact cycle time dramatically.