A Company with no existing wire EDM machines is planning to purchase a new machine. In this instance some provision will need to be made to create programs for the machine. If a company has no existing CAD/CAM software then the purchase of a new system will be needed. The distributor who is selling the machine may make a recommendation as to which CAD/CAM system will work best with their equipment. This recommendation should be given some significance, however you should be aware that many machine tool distributors have little if any experience in advanced software such as CAD/CAM. Many factors should be weighed in determining which product is best for your needs. Any product that is purchased should be capable of utilizing the advanced capabilities of a specific wire EDM machine. It would be unwise to purchase a package that specializes in a single manufacturer; this will limit the choices when it comes time to purchase additional machines. If there are any doubts concerning support for other manufacturers simply ask the distributor for a users list of companies using the software with other types of equipment. Don’t hesitate to call these users, and be specific in questioning them when they contacted. Another good source of information may be the applications department at the machine manufacturer. The applications engineers will likely have experience with customers with a variety of software packages.

A Company with no existing wire EDM machines is planning to purchase a used machine. In this case the software decision may become more critical. The reason being that older machines have less sophisticated controls and are sometimes awkward to program, requiring special codes and programming techniques not required by newer controls. Once again the dealer who is selling the equipment may suggest a system, but beware; they may know little about the programming requirements of a specific machine as they may deal in a number of different manufacturers and models. If it were possible to contact the manufacturer, this would be a good source of information. When purchasing an older used machine it is best to consider only well established companies with a long history in the EDM marketplace, as they are more likely to have post processors already developed for your machine. A Company trying to implement a new type of technology does not need the added headache of becoming the test site for software development.

A Company with an existing wire EDM machine is purchasing a new machine. In this situation there is most likely already some type of programming system in place. It is only natural to assume that by simply purchasing a new post processor for the current system the problem will be resolved with a minimum of time and expense. This may be true if the existing system is relatively current and supports the new equipment. The evolution of CAD/CAM systems has been accelerated in recent years due to the competitive nature of the marketplace and the advancements in computer hardware. If the system that is in place is lagging behind the technology, serious consideration should be given to updating to a newer version or perhaps an entirely new package. This will not only insure support for the advanced features of the new equipment but may increase productivity on the older equipment.

A Company has an existing machine in place and is planning no new purchases. This situation represents a classic example of "If it’s not broken, then don’t fix it" mentality. If the current system and machine are producing parts with few if any errors then why spend the time and money to purchase a new system. Additionally, staff will have to be retrained and there will be a learning curve. The simple answer is Productivity. If the current system makes it difficult and tedious to program parts to run unattended then chances are they are not programmed that way. If programming complex parts such as: gears, cams, and 4-axis work is impossible or extremely difficult, then work is probably being turned away that could be cut if there were a method to efficiently program it. A further concern may exist if the company no longer supports the version of the software, or worse, is no longer in business.

Now that we have reviewed these situations let’s take a look at the criteria that should be used to determine which software package if any will provide the productivity needed to allow the wire EDM equipment to perform to its designed capacity.

Hardware Requirements. Any package under consideration should be capable of performing well on a mid-range PC. Special hardware requirements such as: specific network adapter cards or high-end graphics cards should be avoided. These items not only increase the price and limit your choices in computer hardware, they can create problems in the future if they are discontinued or can no longer be serviced. With the amazing power of today’s off-the-shelf computers any system requiring more should be viewed with suspicion.

Ease of Use. It would seem that if a system were designed to operate in Windows then it would necessarily be easy to use. This is not always the case. A system should have an intuitive feel to it, where you naturally understand what to do. To achieve this, a system’s menus should be organized in a logical progression, there should be a limited number of questions in each dialog box, picture icons should be used in addition to text menus whenever possible. A powerful system that is difficult to learn and use is of little value.

Capability. When evaluating systems capabilities, consideration should be given to current needs as well as future requirements. The system that is purchases should have the ability to take advantage of the complete range of functions of the machine tool. Even if only the components that are necessary to program your existing parts are purchased, the ability to add features as the complexity of your work increases should be available. A common mistake is to purchase a system that will handle the present work, but is limited in its capacity to expand, as needs inevitably will.

Price. Although price is almost always a factor in any purchasing decision, it should not be given significant weight. The price of a CAD/CAM system is a fraction of the total cost of the complete package (machine, tooling, and software); it should therefore receive an appropriate amount of consideration. It should be noted that more expensive does not always mean better. Having said that the old rule of "You get what you pay for" generally applies If a package is unbelievably inexpensive it is probably lacking capability, customer support or may simply be a product that is obsolete.

Machines equipped with automatic wire threading. If a machine is equipped with automatic wire threading then it will be necessary to insure that the system will automatically generate the necessary codes for threading and cutting the wire. It should not be necessary to instruct the software each time one of these codes is needed. This adds to program time and increases the possibility for errors. The system should also have the capability to program for unattended machining. This typically involves cutting openings and leaving the slug attached until all roughing cuts have been completed. Then the slugs will be removed using a reverse cut from the original start hole. After the slugs have been removed the trim cuts can be performed automatically. If the CAM system does not automate this process it can be a tedious chore to program it manually and will likely result in this type of machining being ignored.

Machines with submerged cutting capability. Typically extra codes are needed to fill and drain the tank for this type of machine. If the post processor does not automatically generate these codes they will have to be manually added to the program.

Machines with OEM cutting conditions. Most modern wire EDM machines have a set of predetermined cutting conditions for specific materials and wire sizes. It will make programming more efficient if the system has a database of these conditions included. This eliminates the need to look up this data and manually enter it for each program.

Machines with programmable Z-axis. If the machine has a programmable Z-axis then the system should be capable of implementing a Z move during the program. Typically this is used to enable programming of different height work in a common job or to raise the upper guide away from the work during trim cuts on non-submerged machines.

Machines with special equipment (start hole drill, automatic slug removal, etc.). If the machine is equipped with any special equipment it should be confirmed that this equipment is supported. If not, the necessary codes will have to be manually added to the program.

Extrusion Die and Mold shops. These applications obviously will require 4-axis programming capability. However there are several other considerations: Does the system offer variable land heights within the same shape. Does the system offer automatic synchronization of the two shapes? How easy is it to create and edit synchronization points between the two shapes. Many systems only allow you to use points that have been predefined as part of the shape for sync points, this can be limiting if additional points have to be added after the job has been initially programmed. If 4-axis work will be programmed careful scrutiny should be given to how easily this type of work can be can be programmed and more importantly edited after a program is complete.

A modern CAD/CAM system may be the most important factor in the productivity of wire EDM equipment. Invest the time, and thoroughly investigate the systems available. A general-purpose CAD/CAM system may be acceptable, but will it allow for the most efficient use of the machine. A specialized wire EDM CAD/CAM system may be an additional expense, but it is certainly one that can be justified. The penny saved today, may be the pound of productivity lost tomorrow.

About the author

Randy Mell is the President of CAM-1 Inc. In his current position he is involved in product development as well as sales and support of the Esprit CAD/CAM software product. He has been involved in machining since 1976 when he began as an NC programmer for a small manufacturing company in his home state of Illinois. He worked as Senior NC Applications Engineer for KGK International from 1980 through 1985 where he was involved in customer training and support as well as custom turnkey projects. He was a self employed CAD/CAM consultant from 1986 until October of 1998 when he joined an American subsidiary of a European software company as National Sales Manager. During this time he focused his attention primarily on the programming of wire EDM machines and has been involved in the development of several CAM systems specializing in wire EDM. In January of 2002 he left his position as National Sales Manger  to form CAM-1 Inc.

You may contact Randy directly at the following e-mail link rmell@CAM-1.com with any further questions you may have.