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An interview with Mike Lynch conducted by Domenico Galeotalanza

Domenico Galeotalanza, a student at Northeastern University, conducted this email interview with Mike Lynch as part of a project for a paper related to convincing a manager to convert from older, conventional machine tools to CNC machines. We felt others could benefit from his excellent questions.

Domenico Galeotalanza: Describe the origins of your involvement with CNC machining. Comment on previous machining experience and what led you to form CNC Concepts.

Mike Lynch: When growing up, I worked in my father's machine shop, running machines to produce workpieces for the products he invented and marketed. After high school, I went to a local community college that had a great program for tool and die design and machining. I was hired by one of the night instructors to work for GTE Automatic Electric as an entry-level tool designer. Most of the work I did was related to making detail drawings for the real design engineers - and I didn't like it very much. About six months after starting with them, this company bought an NC turret punch press. Knowing I wasn't very happy with the tool design work, my manager allowed me to learn and work with the new NC machine. From GTE, I went to work for Rockwell International, which at the time, had seventeen NC machines. During my two year stay with them, I learned to program them.

I first started teaching CNC with Cincinnati Milacron. I found this the most rewarding of all of my experiences. I was hired by KGK International Corporation, an importer of CNC machine tools, to work as a trainer. During my ten years with KGK, I developed the training methods I still use today. During many of my classes, a student would ask if the course was available in video format. It finally dawned on me that there may be a market for CNC training materials, and that's when I formed CNC Concepts, Inc.

Domenico Galeotalanza: List the 5 most important features that CNC machines offer, which are not available on non-CNC machines. Explain what make these features so important.

Mike Lynch: Different companies see the benefits of CNC somewhat differently. I'll express the answer to this question from the viewpoint of a product-producing company.

Consistency of workpieces produced - Since a CNC machine executes a program, and it will do so in exactly the same fashion time and time again, the consistency of workpieces produced is much better than workpieces run on conventional machine tools.

Faster workpiece machining - Since current model CNC machine tools are guarded (splash guards, windows, etc.) in a much better manner than most conventional machine tools, users can apply the most efficient cutting conditions to attain the best cycle times. Manual machinists tend to nurse-along their machining operations to minimize the chips and coolant are constantly thrown from the work area.

Lowered skill level of machinist - Though there are some misconceptions in this area (some people believe that anyone can run CNC machines without training), the level of skill required to run (but not program) a CNC machine is much lower than that required to run a conventional machine tool - especially in a production environment when the same workpiece is run over and over again.

Complexity of workpieces to be machined - CNC machines can generate very complex motions, making it possible to machine shapes that cannot be generated (or are extremely difficult to generate) on conventional machine tools.

Flexibility, faster turn-around, and smaller lots - Because they're programmable, a given CNC machine can be used to machine a large variety of different workpieces. Most are also designed to minimize downtime between production runs (setup time). Some conventional machines they're replacing (screw machines and transfer lines, for example) are extremely difficult to setup, making them feasible only for larger lot sizes.

Domenico Galeotalanza: Describe some of the specific skills a CNC machinist needs over a manual machinist.

Mike Lynch: By "CNC machinist", I'm assuming you mean a person that is responsible for programming, setting up, and running production. Many workpiece producing companies (job-shops) and tooling manufacturers employ this kind of CNC person and refer to them as CNC technicians. Note that in many workpiece producing companies, the CNC operator is not responsible for programming or setting up. This means they don't need the level of skill a regular machinist possesses. Special skills required of a CNC technician:

Knowledge of computers and application software - While a conventional machinist will have no need for computers, a CNC technician will be using them every day and in almost every facet of their job. Computers are used to create programs, to verify the correctness of programs, and to transfer programs to an from the CNC machine. Even the CNC control has a computer - some of which have Windows operating systems.

Domenico Galeotalanza: Explain a few of the most complex functions that a CNC machine can perform, which can not be handled by any other type of machine.

Mike Lynch: I'll add the word "feasibly" to this question. Given unlimited resources, conventional equipment can be designed to do just about anything that CNC machines can do. With CNC, however, many more of these complex functions are feasible.

Complexity of workpieces machined - I mentioned this in question three. Consider, for example, the machining of the core and cavity of an injection mold. These shapes have traditionally been machined on tracer mills. With CNC, a program provides the commands needed to machine these complex shapes.

Ability to bring workpiece closer to completion - The general nature of CNC machines allows them to handle more machining operations in one setup than is commonly possible on conventional machines. Specific features of CNC machines that are designed to allow this include live tooling on turning centers that make it possible to perform machining operations on a lathe that are commonly done on a mill, rotary tables and indexers on machining centers designed to rotate the workpiece to expose multiple sides of the part to the spindle for machining, and spindle probes on machining centers that make it possible to accurately (and automatically) locate key location surfaces.

Feedback to production control - Since CNC machines have a built-in computer, they can relay information about how they're running to other parts of the company using the same network that other computers in the company are using.

Self diagnostics - Most current model CNC machines include self-checking systems to constantly monitor their own systems. When something goes wrong, they generate an alarm to alert the operator.

Domenico Galeotalanza: Describe any automated features that CNC machines offer which alleviate a machinist's workload.

Mike Lynch: When it comes to actually running production (after programming and setup are completed), just about every major facet of a manual machinist's workload has been alleviated by CNC machine tools. While a manual machinist must be involved with everything happening on a conventional machine, once a CNC operator loads a workpiece and activates the cycle, the CNC machine takes over, completing all tasks a manual machinist normally does. Specific examples include tool changing, speed, feed, and coolant selection, generating the motion needed to machine workpieces (a manual machinist turns hand-wheels to cause motion), and in some cases, even chip removal. Again, just about everything that happens to machine a workpiece is under the control of the CNC machine tool.

Domenico Galeotalanza: Show how CNC machines can be cost effective in the long run, even for a small company that handles precision work.

Mike Lynch: First of all, CNC machines are not nearly as expensive as they once were. Very capable entry-level machining centers and turning centers are selling for under $30,000.00. Comparable manual machines may not be much less than half this price.

Aside from reasonable the price, many small companies, even one-person shops, employ CNC machines even when lot sizes are small and high precision is required. Shop rates for CNC machine tools range from about $30.00 per hour for smaller and less costly machines to well over $200.00 per hour for larger, more expensive machines. At $100.00 per hour, a company can potentially generate about $200,000.00 per year if working the machine one shift ($100.00 per hour times 40 hours per week times 50 weeks), assuming they can keep the machine busy and that they charge for all hours worked (some companies charge for production time but not programming and/or setup time). They must of course, pay their people and maintain tooling. But when times are good, a company can be very profitable with CNC machine tools.

Domenico Galeotalanza: Describe the typical life span of a CNC machine and the maintenance a typical machine will require over the years.

Mike Lynch: I've heard people refer to a "five-year-payback", saying if you can't justify the purchase of a new CNC machine in such a way that it's paid for in five years, you shouldn't buy the machine. At one time, technology was advancing so quickly that over the course of five years, the current equipment being developed made a five-year-old machine obsolete. But today, CNC machines commonly last much longer than five years. This, of course, is related to the initial quality of the machine, how well the machine is maintained and how hard it is worked. I'd say that average life-span is about ten years. Preventive maintenance tasks include oil changes (hydraulic and spindle oils, for example), air and oil filter changes, regular inspections of key components like ways and bearings, and of course, replacement of worn components when inspections reveal problems.

Domenico Galeotalanza: Name some of the most popular type of CNC machines and why companies prefer them so much.

Mike Lynch: The two most popular metal-cutting machines are machining centers and turning centers. These machines are very flexible which lends to their popularity. The conventional machines they replace are milling machines and lathes. Since almost all machinists have run mills and lathes, it makes it quite easy for them to begin working with CNC machining and turning centers. Other popular CNC machines in niche areas include wire EDM machines in tool-rooms, turret punch presses in metal fabrication companies, and CNC routers in woodworking companies. Of course, this just scratches the surface of CNC machine types. Just about every machine tool used to perform a manufacturing operation has a CNC machine counterpart.

Domenico Galeotalanza: Describe any limitations that CNC machines may have. Comment on any disadvantages that these machines may have.

Mike Lynch: a. Misconceptions - I feel the most important limitations have to do with misapplications due to misconceptions. Many people feel that anyone can run these machines without training. So they hire unskilled people and put them on the CNCs, only to find that CNC machinists still need basic machining practice skills in order to maintain the production. Many managers feel that once a job has been run one time, it should run flawlessly in the future. But if anything changes (workpiece raw material hardness or shape, for example), there will be problems the next time the job is run. People unfamiliar with CNC tend to view it as a black art, thinking that anything is possible with the wave of a wand. In reality, a great deal of ingenuity and effort is required of the people working with the CNC machines.

b. False feeling of security - While machines are becoming more fail-safe, mistakes still cause crashes. Nothing tells the operator before he or she presses the cycle activation button that the machine is out of alignment with the program and a crash is going to occur. Operator mistakes can be very costly, causing a great deal of downtime while machines are repaired.

c. Growing pains - Many companies that buy their first CNC machine find it so productive that they go out and buy their second machine very quickly. And then the third. And fourth. And so on. Principles and techniques that can be successfully applied to one or two machines don't work well with twenty. For example, if a company has but one machine, they hire a person to completely handle it. This person programs, sets up, runs production, and even maintains the machine. This method may work well for two machines (having two people that do everything for their respective machines). But it's infeasible to attempt this with a large number of machines, since there will be a great deal of duplicated effort. Many companies that I've visited constantly struggle with how to best utilize their CNC machines.

Domenico Galeotalanza: Briefly describe the ease or displeasure a machinist experiences when operating a CNC machine. Comment on the overall attitude of machinists towards CNC machines.

Mike Lynch: This varies dramatically based upon machine type and the application. Some companies machine very light, clean, easy-to-handle workpieces while others machine heavy, dirty, unstable workpieces. Most CNC machinists would agree, however, that regardless of the degree of comfort or discomfort, running the CNC machine is much less taxing than running its manual counterpart.

Domenico Galeotalanza: Describe the future of CNC machining and its position/stronghold in the machining industry today.

Mike Lynch: I would be willing to bet that over 80% of companies that manufacture anything have at least one CNC machine tool. While this may not leave much room for growth in number of companies using CNC machines, the current CNC using companies will be constantly buying more machines and replacing those they have. New areas of development include high speed machining (ultra fast spindles and motion rates), development of high-bred CNCs like mill/turn machines, and continuous improvement of CNC controls to allow easier operation.