Machine choice, automation, and preventive maintenance
August 8, 2007
To say Mr. Gates lived his conviction successfully would be a vast understatement. To say following his path would be enough to create a worldwide business empire with annual sales of $44.28 billion would be a vast overstatement. Yet, to say you can find many simple ways to help maximize your company's wealth, growth, and overall health would be right on the money. In laser sheet metal processing, one distinct way helps to improve efficiency: Reduce your costs per part.
To reduce costs per part, and thereby achieve greatest efficiency, you must produce the highest quantity, with the best quality, in the shortest amount of time. Three factors will help you do this: an overall reduction of cost per part through advanced cutting technologies; a steady work flow utilizing automation; and preventive maintenance.
You know what you need to produce, from what type of metal, to what quality level, and how much time you have to do it. You can choose from many methods, but only one of them will be the best. Choosing the correct method requires a process of analysis, information, and action. You must analyze your goals, compile information to determine which laser best suits your needs, and then take action on what you know is the best choice. You need to be efficient, and to do so, you must reduce your costs per part in the long run.
Reducing your costs per part should be a choice, not a process. In fact, the process should already be done by the company that sold you the laser. If it invests millions of dollars in research and development annually, those expenses should help enhance your productivity.
The two factors in a cost-per-part calculation are (1) capital-cost payback and (2) operating costs. In choosing between two lasers, the more expensive machine may appear to be the heavier cost burden, but if you look closely, it may be the better investment and will pay off more quickly. If the additional cost comes with additional technologies—pierce controlling, power and frequency ramping, and high-speed cutting—the additional cost is likely to be justified by the machine's additional productivity.
Pierce controlling reduces the cycle time. Advanced pierce control systems have enhanced focus capability and can set a much deeper laser focus. Some lasers even have an infrared eye inside the laser that can see the work area and determine when the pierce is finished. The most advanced pierce control systems monitor and automatically adjust the power and frequency during the piercing process, which reduces the pierce time and improves hole quality. Some lasers have an additional air nozzle to clear away excess material when piercing.
Power and frequency ramping increase quality. It is most commonly used for material thinner than 3 mm and is used with air and nitrogen cutting techniques. Because a laser must decrease its travel speed to zero when going around a corner or tight feature, it may experience problems with the cut quality if it cannot power down while slowing down. However, some modern lasers use power and frequency ramping to power the resonator down and back up in synchronization with the drives. This eliminates the need for additional cut paths to produce sharp corners and thus decreases cycle time while increasing part quality.
High-speed cutting, also used with materials thinner than 3 mm, reduces cycle time. What the name does not imply is the distinction among assist gas choices that can be used with this technology. Assist gas choice is becoming increasingly important as demands continue for lower costs, reduced cutting time, and increased quality. Compressed air is much less expensive than nitrogen, yet it may not be a proper substitute in some instances. Some lasers can cut effectively with both, and some cannot.
It is more important to choose the right laser than the best laser. Time is money, money is time, and judicious use of automation helps to ensure you use both wisely. Automation provides three distinct benefits: It enables you to run the laser unattended, it decreases downtime, and it eliminates dangerous or redundant tasks performed by an operator.
Having a steady work flow is essential to your company's competitiveness. Automation will help you get the most out of your laser. Consider the additional output that comes from running an additional shift or two, especially if the laser runs unattended. Determining whether automation is beneficial is a matter of weighing the initial cost against the potential productivity increase.
Mrs. Allen's observation is fairly accurate. Maintenance is necessary for preserving the value of many possessions. This isn't limited to vehicles—it applies to industrial machinery also. If treated properly, a machine should not be a financial burden.
The cost of maintaining a laser cutting machine properly is far less than the cost of neglecting it.
Adhering to a preventive maintenance program will help to ensure your laser runs smoothly. Often fabricators do not know that they are lacking preventive maintenance until significant problems emerge. This tends to happen rather late in the machine's life. The emphasis should be on preventing problems rather than fixing problems.
Experienced technicians usually have a general sense of how to service a new machine, but as technologies evolve, new challenges emerge. Some fabricators make the shortsighted mistake of exchanging their experienced and trained workers for cheap, minimum-wage labor, especially during difficult economic times. Such staff changes almost always lead to maintenance complications.
Preventive maintenance actually starts in selecting the installation location for the machine. Installing a laser next to a frequently used door to the outside can cause temperature-related problems. Inadequate floor space can lead to complications from vibrations from other machines located too close to the laser. In today's competitive market, no such detail is too small to ignore. Such small problems can occur at any time or stage of a machine's life.
You might not be able to prevent every problem, but most are easily addressed with adequate planning and preventive maintenance.