Five Axis Machining
Posted : October 15, 2004 at 10:27 am [IST]
Machining with five-axis equipment can offer manufacturers many advantages- improved productivity, higher machining accuracy, reduced in-process inventory, and improved operator and machine usage. For certain applications, particularly in aerospace, automotive and die/mold applications can realize substantial payoffs from five-axis machining, especially as costs for the latest five-axis gear have declined.
Aerospace application of five axis machine is preferred due to the basic design of highly contoured aircraft components. There are very few, if any, parts in aircraft structures that have straight lines on them. Modern fighters and bombers, are getting stealthier. That gets translated into more contour, more curvature than ever before, and so they require to be machined on five-axis equipment. Standardized tooling saves money and lead time for manufacturers. The trend is toward monolithic structures in aerospace design.. In earlier time, multiple sheet-metal components that were manufactured and then fastened together mechanically, which demanded a lot of additional assembly tooling and assembly labor. When other options are not allowed based on the geometry, the option left is full five axis. And the only industry where we’ve seen that happen at the moment is in the aerospace industry, like with blisk work, which is a combination of blade and disk. Five-axis configurations vary widely depending on the application, but the most common one is with both rotary axes are on the spindle.
Programming complexity, aside from high cost, has posed the biggest barriers to widespread adoption of five-axis machinery. Five-axis machines continue to get faster and more accurate, so it’s a technology that’s emerging. It has its applications, but it is certainly not a mature, fully functional technology yet. CAM systems are still very weak. The learning curve for a CAD/CAM operator to become very good with five-axis is a challenge for small shops. Very few CAM systems can give you good data for full five-axis machining.
Die/mold can take advantage of three-axis or 3+2. Among the European builders, there’s a huge push in the five-axis machining centers for die/mold. Benefits to the five-axis approach, in terms of being able to hit multiple sides of the parts and being able to shorten the tool length on side walls, are considerable. CAM software and the sheer cost of five-axis machine tools are now less of an issue than in recent years In Europe, manufacturers readily accepted five-axis machining as a way to help compete with lower-cost labor centers in Asia and also in Eastern Europe. Because labor’s so cheap in other markets, companies that want to remain competitive have to start machining smarter, which doesn’t mean just machining faster or working longer hours. It means looking really closely at your current processes, focusing on your application, and investing in new technology, training, correct tooling, and a host of other factors to cut down lead times, so we can remain competitive. However, these machines aren’t cheap. It’s all right if you’re a large manufacturer, but for a tooling company that is thinking of investing in this technology, it’s a big money. For smaller tool-and-die shops, five-axis equipment ranging from $100,000 to $1 million is a major investment, but over the last few years these machines are more affordable for these smaller shops.
Smaller shops are now seeing advantages to using five-axis and 3+2 technology. In the tool-and-die industry, 90% of the jobs can be machined extremely efficiently using 3+2 technology, because it provides greater flexibility to cut the part, reduce tool length, improve surface finish, and one can still employ high-speed, high-efficiency machining techniques.
The progression has gone from three to 3+2-axis machining, where tool length can be shortened and machine can be run at high speeds as well. With simultaneous five-axis, all axes move at the same time
Programming for simultaneous five-axis machining is complex Programming for five-axis requires much more consideration than for 3+2 machining. Part geometry, workpiece orientation, and entry and exit conditions are extremely important. Good collision detection is absolutely essential. One must be surely know what’s happening and that the head of the machine isn’t colliding with the part, clamps, or fixturing. Many CAM software packages claim provision for ‘gouge-free’ toolpaths which are verified against the tool and the holder but not for the machine itself, which is essential for five-axis programming.
High-speed machining also plays a key role in manufacturers deploying five-axis systems to speed up their manufacturing processes. To apply five-axis machining techniques effectively, users need to find the proper solutions for their particular application. Users should seek out credible experts in five-axis machining. It can be quite confusing to new users entering this field, which can lead to discouragement and a loss of return on the investment. Speed, accuracy, and flexibility combined with manufacturing knowledge and experience can help users find the right tools for their needs. With five-axis machines, in the past the limiting factor was the speed of the rotary tables, but today’s five-axis machines possess faster rotary tables.
However, five-axis machining is a smaller market. Some manufacturers have sold well into high-production machining applications, particularly into engine manufacturing, where five-axis equipment helps reduce setups. By reducing setups, it cuts down on work in process. The machines are doing well with jet engine components, prismatic parts, and engine components in automotive. Fast, single setups often make five-axis machining more efficient than three-axis equipment. Customers can mill, drill, tap, and saw parts to length in one setup, eliminating the need for any other machine or material handling system
Five axis machining provides the concept of one machine factory. Though the investment is high, but there is always a need of special complex parts manufacturing and that ensuring the best quality. Five axis machines are the answer.
- Indra
Category: Machining |
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