http://drishtikona.com My online journal with thoughts, opinions, comments and more.. Tue, 07 Oct 2008 13:24:34 +0000 http://wordpress.org/?v=2.1.2 http://drishtikona.com/images/favicon.gif http://drishtikona.com en http://drishtikona.com/archives/machining/001670.php http://drishtikona.com/archives/machining/001670.php#comments Wed, 28 Mar 2007 14:05:05 +0000 Indra http://drishtikona.com/archives/machining/001670.php Machining Industry Can Lead Indian Manufacturing Sector Machining has been an important manufacturing process for ages for engineering industry. A large number of parts going in the final assemblies of the products, be it aeroplanes or automobiles require machining operations to finish them within critical tolerances for optimum functioning over the life cycles. Over the years, there have been sea changes in all areas of the machining, be its the machine tools, the cutting tools, fixturing, or other accessories such as cooling agents. But some changes are almost universal in all these. Flexibility, reconfigurability, modularity, ease and error free automatic operations, and serviceability have been the main goals. CNC Machining centers and turning centers have replaced different machine tools for varying machining operations, such as drilling, reaming, boring, and even turning, grinding and even broaching. Even a complicated component such as cylinder blocks of an automobile engine or a sophisticated huge sheet metal stamping die tools can almost be totally machined in a single setup today on one machine. Cutting tool materials today can machine harden above 60Rc pieces and that too without any cooling agent that used to cause a lot of nuisance on the shop floor. In next step, perhaps the cutting tools will be smart enough to automatically switch over the cutting parameters depending on the real machining characteristics of the material being machined. Workholding fixtures are smarter to control precisely the grip force required for the cutting parameters without deforming the features as it comes out of the machine tools after the finishing operations. But the most important input has come from the Internet compatible controls that has made troubleshooting and maintenance manageable even for sophisticated items by removing the need of the expert to be physically present to assist on the machine tools. Some of new trends that has helped the machining to be more productive are the near net shape basic forming processes for precision casting and forging that have eliminated the need of three step machining to one. Simultaneously, in some sector such as aeroplane industry, the components are getting bulk machined from almost raw billets integrating number of components in one thus eliminating assembling operation and tolerance stack up. The advent of high speed machining and hard machining has also facilitated the production engineers to eliminate number of machining steps. Surprisingly, no innovation has come in basic machine tool design to replace the machining/turning centers that once was predicted. For India, it is necessary that it becomes a manufacturing nation so that huge employment gets created to exploit its demographical advantages to the best. Machining industry can be one area that can serve the purpose. Some may say that it is capital intensive, but with machining center when one machine can be used to finish many components totally, it can be commercially viable business. I am pained that India even today does not facilities good enough to manufacture all the die tools of the automotive industry, and the OEM manufacturers both domestic and global with presence in India are dependent to get it from other cheaper countries such as Japan, Taiwan, South Korea, or perhaps from China and Thailand. One can appreciate the need by looking at the number of die tools involved in creating a new model of car and its cost. Will the OEMs keep on importing them with frequent changes of models that will be expected from the Indian automotive enthusiasts and consumers? My other agony relates to the machine tools industry. Unfortunately, with all opportunity not a single machine tools company could grow to a global scale though all the necessary skill and talent with demand too was there. Naturally, an ambience is to be created by the government agencies such as National Manufacturing Competitiveness Council (NMCC) so that more and more of the graduate engineers start thinking of becoming entrepreneurs in manufacturing sector. CMERI can also be a motivating force. ]]> Machining Industry Can Lead Indian Manufacturing Sector Machining has been an important manufacturing process for ages for engineering industry. A large number of parts going in the final assemblies of the products, be it aeroplanes or automobiles require machining operations to finish them within critical tolerances for optimum functioning over the life cycles. Over the years, there have been sea changes in all areas of the machining, be its the machine tools, the cutting tools, fixturing, or other accessories such as cooling agents. But some changes are almost universal in all these. Flexibility, reconfigurability, modularity, ease and error free automatic operations, and serviceability have been the main goals. CNC Machining centers and turning centers have replaced different machine tools for varying machining operations, such as drilling, reaming, boring, and even turning, grinding and even broaching. Even a complicated component such as cylinder blocks of an automobile engine or a sophisticated huge sheet metal stamping die tools can almost be totally machined in a single setup today on one machine. Cutting tool materials today can machine harden above 60Rc pieces and that too without any cooling agent that used to cause a lot of nuisance on the shop floor. In next step, perhaps the cutting tools will be smart enough to automatically switch over the cutting parameters depending on the real machining characteristics of the material being machined. Workholding fixtures are smarter to control precisely the grip force required for the cutting parameters without deforming the features as it comes out of the machine tools after the finishing operations. But the most important input has come from the Internet compatible controls that has made troubleshooting and maintenance manageable even for sophisticated items by removing the need of the expert to be physically present to assist on the machine tools. Some of new trends that has helped the machining to be more productive are the near net shape basic forming processes for precision casting and forging that have eliminated the need of three step machining to one. Simultaneously, in some sector such as aeroplane industry, the components are getting bulk machined from almost raw billets integrating number of components in one thus eliminating assembling operation and tolerance stack up. The advent of high speed machining and hard machining has also facilitated the production engineers to eliminate number of machining steps. Surprisingly, no innovation has come in basic machine tool design to replace the machining/turning centers that once was predicted. For India, it is necessary that it becomes a manufacturing nation so that huge employment gets created to exploit its demographical advantages to the best. Machining industry can be one area that can serve the purpose. Some may say that it is capital intensive, but with machining center when one machine can be used to finish many components totally, it can be commercially viable business. I am pained that India even today does not facilities good enough to manufacture all the die tools of the automotive industry, and the OEM manufacturers both domestic and global with presence in India are dependent to get it from other cheaper countries such as Japan, Taiwan, South Korea, or perhaps from China and Thailand. One can appreciate the need by looking at the number of die tools involved in creating a new model of car and its cost. Will the OEMs keep on importing them with frequent changes of models that will be expected from the Indian automotive enthusiasts and consumers? My other agony relates to the machine tools industry. Unfortunately, with all opportunity not a single machine tools company could grow to a global scale though all the necessary skill and talent with demand too was there. Naturally, an ambience is to be created by the government agencies such as National Manufacturing Competitiveness Council (NMCC) so that more and more of the graduate engineers start thinking of becoming entrepreneurs in manufacturing sector. CMERI can also be a motivating force. ]]> http://drishtikona.com/archives/machining/001670.php/feed/ http://drishtikona.com/archives/machining/000542.php http://drishtikona.com/archives/machining/000542.php#comments Fri, 15 Oct 2004 04:57:08 +0000 Indra http://drishtikona.com:90/archives/uncategorized/000542.php 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. ]]> 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. ]]> http://drishtikona.com/archives/machining/000542.php/feed/ http://drishtikona.com/archives/machining/000537.php http://drishtikona.com/archives/machining/000537.php#comments Mon, 11 Oct 2004 06:28:55 +0000 Indra http://drishtikona.com:90/archives/uncategorized/000537.php Ferment (growing interest in an idea), 2. Dominant design (several try to develop the idea and one becomes the leading concept), 3. Incremental innovation (the leading concept is improved), and 4. Maturity (the accepted design begins to lose dominance). Williams noted a parallel to this idea in the development of the airplane. First there was an early interest in flight, then the Wright brothers had a successful design. This was followed by the airplane's evolution from wood to aluminum, then composites as the key structural material. "When any given technology is improving at a decreasing rate, it's likely a new technology will emerge to supplant it." Therefore the key to success is to get into the market with a new idea at the time of transition when it's possible to supply something that no one else is offering. But, technology is not always the major issue. "Managing the change in customer preference is often the hardest task." Sometimes a major obstacle to innovation is he calls "the competency trap." It's when a company has a core competency that has been the key to its success in the past. Managers are, therefore, reluctant to take the risk of pushing into new technologies. A second stumbling block is the reluctance to take full advantage of new technology. He cites the current push for HSM (High Speed Machining) where, too often, a company will concentrate on a specific problem and ignore the larger opportunities. For example, HSM not only leads to faster production, but can often mean lighter parts, fewer tools needed, the chance to make modules rather than multipart assemblies, plus the many positive changes in machine tool and cutting tool design. To take advantage of developing technologies Williams suggests: " Watch for signals of a changing technology. " Both component and total system changes offer the opportunity for gain. " Don't rely on tradition. You can't count on a company's established channels for gaging a market because they were not designed for the new technology. " Be ready to manage change. Timing is everything. The history of human kind is the history of the improvements and innovations made by it as a continuous process. The nation that was good in it has done well. When it got choked because of any internal and external reasons, it became difficult to survive what to say to grow. We in India must remember this mantra of improve and innovate in every walk of life to grow in face of the competition. ]]> Ferment (growing interest in an idea), 2. Dominant design (several try to develop the idea and one becomes the leading concept), 3. Incremental innovation (the leading concept is improved), and 4. Maturity (the accepted design begins to lose dominance). Williams noted a parallel to this idea in the development of the airplane. First there was an early interest in flight, then the Wright brothers had a successful design. This was followed by the airplane's evolution from wood to aluminum, then composites as the key structural material. "When any given technology is improving at a decreasing rate, it's likely a new technology will emerge to supplant it." Therefore the key to success is to get into the market with a new idea at the time of transition when it's possible to supply something that no one else is offering. But, technology is not always the major issue. "Managing the change in customer preference is often the hardest task." Sometimes a major obstacle to innovation is he calls "the competency trap." It's when a company has a core competency that has been the key to its success in the past. Managers are, therefore, reluctant to take the risk of pushing into new technologies. A second stumbling block is the reluctance to take full advantage of new technology. He cites the current push for HSM (High Speed Machining) where, too often, a company will concentrate on a specific problem and ignore the larger opportunities. For example, HSM not only leads to faster production, but can often mean lighter parts, fewer tools needed, the chance to make modules rather than multipart assemblies, plus the many positive changes in machine tool and cutting tool design. To take advantage of developing technologies Williams suggests: " Watch for signals of a changing technology. " Both component and total system changes offer the opportunity for gain. " Don't rely on tradition. You can't count on a company's established channels for gaging a market because they were not designed for the new technology. " Be ready to manage change. Timing is everything. The history of human kind is the history of the improvements and innovations made by it as a continuous process. The nation that was good in it has done well. When it got choked because of any internal and external reasons, it became difficult to survive what to say to grow. We in India must remember this mantra of improve and innovate in every walk of life to grow in face of the competition. ]]> http://drishtikona.com/archives/machining/000537.php/feed/ http://drishtikona.com/archives/machining/000527.php http://drishtikona.com/archives/machining/000527.php#comments Mon, 04 Oct 2004 01:35:07 +0000 Indra http://drishtikona.com:90/archives/uncategorized/000527.php Flexible manufacturing Flexibility requirements have almost made the application of traditional inline transfer lines obsolete. Incorporation of NC-controlled feed units, multi-axis NC-units, swiveling drilling heads, sometimes head changers, flexible design of work transfer pallets provides a lot of flexibility in present generation of transfer line to be called rightly as flexible transfer. The idea of using even high speed machining center modules for flexible transfer line in the auto industry has become quite popular. Transfer system may be similar to traditional transfer lines, power and free conveyor, or conventional electromechanical one such as lift and carry system used in high production line. For lesser flexibility required by high production line, a trend is to strip machine tools of redundant features to trim prices by 30 to 50 %. Some simply reduce the number of control axes, cheaper controllers, and/or tool magazine's capacity. Designers throughout the machine tool industry are working hard to make these high-tech machines cost competitive with conventional machines. Systems used for high production machining may be: "Sequential machining on three-axis modular production-type machining centers with limited tool-changer capacity (say, 6 to 24), and dedicated hydraulic fixtures. Units can also be installed as wing bases on a dial index machine. In another setup, units can be positioned close together to form a transfer machine. Appropriate machines - heavier machining centers for milling operations; lighter and high speed ones for drilling, and reaming; a tapping center for fast tapping; a very precision unit for close tolerance boring; may constitute the machining line. The part moves ahead in sequence passing through all the machining stations. " Asequential machining features identical CNC machining centers with a larger tool-changer capacity, each of which can do all machining operations for each part assigned to the cell, including milling, drilling, boring, counter-boring, and tapping. The system takes care of a machine-breakdown easily. The system may start with minimum number of machines, and grows with addition of machines as the production increases. The part moves as programmed to different work-stations depending on real time situation. Agile manufacturing A switchover from flexible manufacturing to agile manufacturing system is becoming a necessity. It provides the unlimited scope of changeover over the limited scope of change in flexible manufacturing. Instead of building something that anticipates a defined range of requirements based on ten or twelve contingencies in flexible manufacturing, the emphasis by an agile system is to build something that can be deconstructed and reconstructed as needed. Present trend prefers the use of cost-effective single spindle machining centers that are configurable as both transfer machine modules and standalone machines, capable of high force, high speed machining, and optimized for a range of materials from aluminum to cast iron. All the machine tools for medium to high production are being designed with built-in agility as a necessary feature. For example, the totally self-contained electrical and power units are designed with a 'single plug' system. Even a precision machine today is moved with a forklift truck, and then with a few connections and leveling, it gets ready for production. Agility does not compromise stability. ]]> Flexible manufacturing Flexibility requirements have almost made the application of traditional inline transfer lines obsolete. Incorporation of NC-controlled feed units, multi-axis NC-units, swiveling drilling heads, sometimes head changers, flexible design of work transfer pallets provides a lot of flexibility in present generation of transfer line to be called rightly as flexible transfer. The idea of using even high speed machining center modules for flexible transfer line in the auto industry has become quite popular. Transfer system may be similar to traditional transfer lines, power and free conveyor, or conventional electromechanical one such as lift and carry system used in high production line. For lesser flexibility required by high production line, a trend is to strip machine tools of redundant features to trim prices by 30 to 50 %. Some simply reduce the number of control axes, cheaper controllers, and/or tool magazine's capacity. Designers throughout the machine tool industry are working hard to make these high-tech machines cost competitive with conventional machines. Systems used for high production machining may be: "Sequential machining on three-axis modular production-type machining centers with limited tool-changer capacity (say, 6 to 24), and dedicated hydraulic fixtures. Units can also be installed as wing bases on a dial index machine. In another setup, units can be positioned close together to form a transfer machine. Appropriate machines - heavier machining centers for milling operations; lighter and high speed ones for drilling, and reaming; a tapping center for fast tapping; a very precision unit for close tolerance boring; may constitute the machining line. The part moves ahead in sequence passing through all the machining stations. " Asequential machining features identical CNC machining centers with a larger tool-changer capacity, each of which can do all machining operations for each part assigned to the cell, including milling, drilling, boring, counter-boring, and tapping. The system takes care of a machine-breakdown easily. The system may start with minimum number of machines, and grows with addition of machines as the production increases. The part moves as programmed to different work-stations depending on real time situation. Agile manufacturing A switchover from flexible manufacturing to agile manufacturing system is becoming a necessity. It provides the unlimited scope of changeover over the limited scope of change in flexible manufacturing. Instead of building something that anticipates a defined range of requirements based on ten or twelve contingencies in flexible manufacturing, the emphasis by an agile system is to build something that can be deconstructed and reconstructed as needed. Present trend prefers the use of cost-effective single spindle machining centers that are configurable as both transfer machine modules and standalone machines, capable of high force, high speed machining, and optimized for a range of materials from aluminum to cast iron. All the machine tools for medium to high production are being designed with built-in agility as a necessary feature. For example, the totally self-contained electrical and power units are designed with a 'single plug' system. Even a precision machine today is moved with a forklift truck, and then with a few connections and leveling, it gets ready for production. Agility does not compromise stability. ]]> http://drishtikona.com/archives/machining/000527.php/feed/ http://drishtikona.com/archives/machining/000521.php http://drishtikona.com/archives/machining/000521.php#comments Wed, 29 Sep 2004 14:49:51 +0000 Indra http://drishtikona.com:90/archives/uncategorized/000521.php Machining centres have brought flexibility in manufacturing of mechanical parts at all volumes. And the machine tools are now agile enough and moving towards virtual machining systems. ]]> Machining centres have brought flexibility in manufacturing of mechanical parts at all volumes. And the machine tools are now agile enough and moving towards virtual machining systems. ]]> http://drishtikona.com/archives/machining/000521.php/feed/ http://drishtikona.com/archives/machining/000518.php http://drishtikona.com/archives/machining/000518.php#comments Tue, 28 Sep 2004 13:22:50 +0000 Indra http://drishtikona.com:90/archives/uncategorized/000518.php New Materials There is an increased emphasis on the uses of titanium and titanium alloys. The auto industry is going for more aluminum-silicon alloys as well as some magnesium, The industry is also showing increasing interest in compacted graphite iron [CGI]- a variant of ductile iron. Though the tools that work well on ductile iron can, in general, do the job on CGI as well, but the absolute tool life is likely to be less when cutting CGI because of its abrasiveness and higher yield strength. Flank wear resistance is particularly important with this metal. Among the trends: " The nickel-based alloys are becoming more difficult to machine. " Whisker ceramics and improved Sialons continue to be used. " Sialons have extended the property range and toughness. " Titanium/aluminum (TiAl) coatings have improved for cutting stainless, regular steels, and cast irons. This is because PVD technology has improved coating adhesion. TiAlN coatings have better adhesion, and for cutting aluminum give better chemical stability and they dissolve more slowly in ferrous materials, and have higher hardness levels. As a result, tool life is longer and cutting speeds are higher. Coatings have made major improvements. Majority of tools are coated. For the greatest portion PVD is used. At the same time there has been a surprisingly rapid development of CVD technology, chiefly improvements in adhesion to substrates and between layers. There have also been improvements in coating smoothness and thickness. Turning-tool coatings are now more than 20 µm and milling tools are up to 7µm. There is now greater use of substrates with cobalt content less than 6%. They are used in high-volume ferrous machining applications. This reflects the trend in machining to higher speeds, smaller DOC, and fewer interrupted cuts. There is a clear trend away from HSS to cemented carbide in end mills because new machining centers with higher speeds are stiffer and need more wear resistant tools. Milling is an area where big improvements in indexable end mills have been made. A new system called Mill 1- offers better surface finish, while requiring less power and lower cutting forces. The perpendicularity is now close to a true 90º, and it has good ramping capabilities. Another innovation is the insert screw is mounted at an angle, instead of the traditional perpendicular mount. This has two advantages. It pulls the insert into the holder more tightly and has more screw threads engaging the holder. As a result cutting speeds can be higher. In the last two years, there has been a lot of growth in applications of lightweight nonferrous materials as well as hardened steel and other difficult-to-machine ferrous materials. As a result, the market has significantly increased for custom-engineered round tools with brazed cutting edges of PCD or PCBN for milling, drilling, and reaming operations. Custom round tools with fixed cutting edges are intended for machining parts with small-diameter holes of approximately 0.25" [13 - mm] diameter where the restricted space is a problem for insert-type cutting tools. They also apply for parts with relatively tight tolerances in the range of 3 - 5 µin. [0.002 µm] because of the possibility of cutting-edge movement with inserted-type cutting tools. Ways are being found to cut deliveries of round tools by half or more by automating the process. Using the new software, standard delivery for high-precision custom round tools is 10 weeks, and in some cases as little as four weeks. Our industry moves ahead relatively slowly, with cutting tool development usually ahead of machine tool performance. However, currently 70,000 rpm is achievable on the machine and spindle end, but at this time the inserts won't hold up. Aerospace is where we most often see new alloys being used, then it falls on the cutting tool makers to develop products that will work Recently there have been some advances in diamond tooling. Iinsert grades for turning steels and stainless steels are being designed for dry machining through a combination of wear resistance and edge toughness. Getting rid of coolant can extend tool life. New inserts offer reliability and improved surface finishes in medium-duty turning of steels because its toughness resists chipping. The inserts combine superior core toughness, high wear resistance and sophisticated chipbreaker geometries, and are especially designed to withstand heavy roughing, interrupted cuts, high-feed applications and processes on materials with high piece-to-piece or batch-to-batch variability. A new line of indexable insert drills have a combination of features that allow drilling with much faster speeds and feeds even on applications with long overhangs, workpieces with poor fixturing, and thin-walled parts. The entire drilling line, which covers a range of 0.594 - 2.375" [6 - 60-mm] diam and drilling depth capabilities from 2XD to 5XD, uses square inserts with 90º corners. The drill body resists deflection and evacuates chips. Plus, the drills have a non-stick coating that further enhances performance and drill life. Tools are being developed to meet the industry's requirement of lean manufacturing.]]> New Materials There is an increased emphasis on the uses of titanium and titanium alloys. The auto industry is going for more aluminum-silicon alloys as well as some magnesium, The industry is also showing increasing interest in compacted graphite iron [CGI]- a variant of ductile iron. Though the tools that work well on ductile iron can, in general, do the job on CGI as well, but the absolute tool life is likely to be less when cutting CGI because of its abrasiveness and higher yield strength. Flank wear resistance is particularly important with this metal. Among the trends: " The nickel-based alloys are becoming more difficult to machine. " Whisker ceramics and improved Sialons continue to be used. " Sialons have extended the property range and toughness. " Titanium/aluminum (TiAl) coatings have improved for cutting stainless, regular steels, and cast irons. This is because PVD technology has improved coating adhesion. TiAlN coatings have better adhesion, and for cutting aluminum give better chemical stability and they dissolve more slowly in ferrous materials, and have higher hardness levels. As a result, tool life is longer and cutting speeds are higher. Coatings have made major improvements. Majority of tools are coated. For the greatest portion PVD is used. At the same time there has been a surprisingly rapid development of CVD technology, chiefly improvements in adhesion to substrates and between layers. There have also been improvements in coating smoothness and thickness. Turning-tool coatings are now more than 20 µm and milling tools are up to 7µm. There is now greater use of substrates with cobalt content less than 6%. They are used in high-volume ferrous machining applications. This reflects the trend in machining to higher speeds, smaller DOC, and fewer interrupted cuts. There is a clear trend away from HSS to cemented carbide in end mills because new machining centers with higher speeds are stiffer and need more wear resistant tools. Milling is an area where big improvements in indexable end mills have been made. A new system called Mill 1- offers better surface finish, while requiring less power and lower cutting forces. The perpendicularity is now close to a true 90º, and it has good ramping capabilities. Another innovation is the insert screw is mounted at an angle, instead of the traditional perpendicular mount. This has two advantages. It pulls the insert into the holder more tightly and has more screw threads engaging the holder. As a result cutting speeds can be higher. In the last two years, there has been a lot of growth in applications of lightweight nonferrous materials as well as hardened steel and other difficult-to-machine ferrous materials. As a result, the market has significantly increased for custom-engineered round tools with brazed cutting edges of PCD or PCBN for milling, drilling, and reaming operations. Custom round tools with fixed cutting edges are intended for machining parts with small-diameter holes of approximately 0.25" [13 - mm] diameter where the restricted space is a problem for insert-type cutting tools. They also apply for parts with relatively tight tolerances in the range of 3 - 5 µin. [0.002 µm] because of the possibility of cutting-edge movement with inserted-type cutting tools. Ways are being found to cut deliveries of round tools by half or more by automating the process. Using the new software, standard delivery for high-precision custom round tools is 10 weeks, and in some cases as little as four weeks. Our industry moves ahead relatively slowly, with cutting tool development usually ahead of machine tool performance. However, currently 70,000 rpm is achievable on the machine and spindle end, but at this time the inserts won't hold up. Aerospace is where we most often see new alloys being used, then it falls on the cutting tool makers to develop products that will work Recently there have been some advances in diamond tooling. Iinsert grades for turning steels and stainless steels are being designed for dry machining through a combination of wear resistance and edge toughness. Getting rid of coolant can extend tool life. New inserts offer reliability and improved surface finishes in medium-duty turning of steels because its toughness resists chipping. The inserts combine superior core toughness, high wear resistance and sophisticated chipbreaker geometries, and are especially designed to withstand heavy roughing, interrupted cuts, high-feed applications and processes on materials with high piece-to-piece or batch-to-batch variability. A new line of indexable insert drills have a combination of features that allow drilling with much faster speeds and feeds even on applications with long overhangs, workpieces with poor fixturing, and thin-walled parts. The entire drilling line, which covers a range of 0.594 - 2.375" [6 - 60-mm] diam and drilling depth capabilities from 2XD to 5XD, uses square inserts with 90º corners. The drill body resists deflection and evacuates chips. Plus, the drills have a non-stick coating that further enhances performance and drill life. Tools are being developed to meet the industry's requirement of lean manufacturing.]]> http://drishtikona.com/archives/machining/000518.php/feed/ http://drishtikona.com/archives/machining/000515.php http://drishtikona.com/archives/machining/000515.php#comments Mon, 27 Sep 2004 03:50:43 +0000 Indra http://drishtikona.com:90/archives/uncategorized/000515.php Grinders are going multifunction Customers are pushing to improve their capital investment payback through faster cycle times. Capital equipment cost and payback time is becoming critical. Multifunction machines are becoming more common. There is a big move to incorporate grinding on turning centers, and turning or burnishing on grinders. Grinding is often introduced to improve dimensional accuracy or finish after turning. Some sectors of the market are becoming mature for super-abrasives, such as cam and crank grinding, while other sectors are just waking up to this material's potential. This includes through-feed centerless grinding with vitrified CBN, where falling grain prices are reducing the sticker shock of large wheels. There is an upsurge in acceptance of oil coolant. This allows novel processing methods such as high-speed peel or contour grinding, common in Europe, to be introduced into the USA as a challenge to hard turning. Major developments in the vitrified products area: " The T2 bond technology which continues to make major performance improvements in an increasing number of applications. " Dressing technology (rotary diamond dressers and motorized dresser spindles) to match the performance requirements of the wheels. In conventional wheel developments " Norton XPG.90 grinding wheels last up to 10 times longer than previous wheels on fluting, pointing, and punch grinding applications Flexible grinding platforms that address both production and short-run needs are becoming more and more in demand. This requires innovations to both software and hardware on today's grinding machines. This could be a machine with an easy to adjust loader. A loader, designed for the needs of small shops that want flexible automation, allows quick adjustment when the operator makes parts of differing lengths. Another example is adding toolchangers to grinding machines. This allows an operator to fixture a part on a grinder, then walk away. The new tool-changing technology increases the variety of applications to a great extent by increasing the number of operations that can be accomplished without operator interference. By limiting operator involvement and eliminating the need to move a part from machine to machine the new toolchanger enhances process control and results in consistent performance and quality parts. If the initial process parameters are correct, we can pretty much eliminate scrap as an issue. With this toolchanger, the operator can load all the tools required to finish a part -- multiple abrasive types, conventional wheels, aluminum oxide, CBN, and, of course, drills, mills, and taps. The idea is to have the perfect abrasive or tool in the changer for a particular part. You can rough with one type of abrasive and finish with another. Perhaps you have a feature that requires a very well-defined wheel diameter, and perhaps plated CBN would be best. However, you may have other features on the same part where the stock is heavy and requires more conventional abrasives. With this design it's possible to intermix tools and abrasives around the specific requirements of a given part and run that part complete, start to finish, in a single setup. Typical applications include turbine vanes and blades, gear shifting shafts, rocker arms, small turbine and compressor blades, machining both sides of fir tree and root shank faces, shroud and Z-notch profiles -- both sides and slots if required. Part tolerances and processability requirements have become increasingly tighter in response to the demand for improved quality with lower cost. A manufacturer of fuel-system components, for example, now centerless grinds plungers at very high production rates to tolerances of 1 µm on diameter and 0.6 µm on taper at 1.33 Ppk. Many request to grind very tough materials such as Inconel bolts for aerospace and specialty alloy steel bars for various precision applications. Many part designs have become more complex, such as families of crankshafts with multiple throws or camshafts with multiple features that must be accommodated in finish grinding. And many manufacturers have been seeking to replace multi-operation, dedicated processes with more efficient grinding processes using fewer machines that combine operations. The latest generation of flexible CNC production grinders from Landisi incorporates superabrasive wheels operating at very high speed and feature reliable, wear-free linear motor drives and the latest generation of PC-based open-architecture controls. Some of these new grinders can also minimize the number of machines in a process and reduce capital expenditure for our customers by combining multiple grinding operations in a single machine. For example, a typical five-machine crankshaft grinding process can now be reduced to only two machines by grinding crankshaft concentric diameters, including thrust-walls and eccentric crankpins, with an LT2 Twin Wheelhead grinder, one of the machines. Landis has also developed a machine for grinding crankshaft thrust-walls, flange face, pilot diameters, and reluctor ring all in one machine.]]> Grinders are going multifunction Customers are pushing to improve their capital investment payback through faster cycle times. Capital equipment cost and payback time is becoming critical. Multifunction machines are becoming more common. There is a big move to incorporate grinding on turning centers, and turning or burnishing on grinders. Grinding is often introduced to improve dimensional accuracy or finish after turning. Some sectors of the market are becoming mature for super-abrasives, such as cam and crank grinding, while other sectors are just waking up to this material's potential. This includes through-feed centerless grinding with vitrified CBN, where falling grain prices are reducing the sticker shock of large wheels. There is an upsurge in acceptance of oil coolant. This allows novel processing methods such as high-speed peel or contour grinding, common in Europe, to be introduced into the USA as a challenge to hard turning. Major developments in the vitrified products area: " The T2 bond technology which continues to make major performance improvements in an increasing number of applications. " Dressing technology (rotary diamond dressers and motorized dresser spindles) to match the performance requirements of the wheels. In conventional wheel developments " Norton XPG.90 grinding wheels last up to 10 times longer than previous wheels on fluting, pointing, and punch grinding applications Flexible grinding platforms that address both production and short-run needs are becoming more and more in demand. This requires innovations to both software and hardware on today's grinding machines. This could be a machine with an easy to adjust loader. A loader, designed for the needs of small shops that want flexible automation, allows quick adjustment when the operator makes parts of differing lengths. Another example is adding toolchangers to grinding machines. This allows an operator to fixture a part on a grinder, then walk away. The new tool-changing technology increases the variety of applications to a great extent by increasing the number of operations that can be accomplished without operator interference. By limiting operator involvement and eliminating the need to move a part from machine to machine the new toolchanger enhances process control and results in consistent performance and quality parts. If the initial process parameters are correct, we can pretty much eliminate scrap as an issue. With this toolchanger, the operator can load all the tools required to finish a part -- multiple abrasive types, conventional wheels, aluminum oxide, CBN, and, of course, drills, mills, and taps. The idea is to have the perfect abrasive or tool in the changer for a particular part. You can rough with one type of abrasive and finish with another. Perhaps you have a feature that requires a very well-defined wheel diameter, and perhaps plated CBN would be best. However, you may have other features on the same part where the stock is heavy and requires more conventional abrasives. With this design it's possible to intermix tools and abrasives around the specific requirements of a given part and run that part complete, start to finish, in a single setup. Typical applications include turbine vanes and blades, gear shifting shafts, rocker arms, small turbine and compressor blades, machining both sides of fir tree and root shank faces, shroud and Z-notch profiles -- both sides and slots if required. Part tolerances and processability requirements have become increasingly tighter in response to the demand for improved quality with lower cost. A manufacturer of fuel-system components, for example, now centerless grinds plungers at very high production rates to tolerances of 1 µm on diameter and 0.6 µm on taper at 1.33 Ppk. Many request to grind very tough materials such as Inconel bolts for aerospace and specialty alloy steel bars for various precision applications. Many part designs have become more complex, such as families of crankshafts with multiple throws or camshafts with multiple features that must be accommodated in finish grinding. And many manufacturers have been seeking to replace multi-operation, dedicated processes with more efficient grinding processes using fewer machines that combine operations. The latest generation of flexible CNC production grinders from Landisi incorporates superabrasive wheels operating at very high speed and feature reliable, wear-free linear motor drives and the latest generation of PC-based open-architecture controls. Some of these new grinders can also minimize the number of machines in a process and reduce capital expenditure for our customers by combining multiple grinding operations in a single machine. For example, a typical five-machine crankshaft grinding process can now be reduced to only two machines by grinding crankshaft concentric diameters, including thrust-walls and eccentric crankpins, with an LT2 Twin Wheelhead grinder, one of the machines. Landis has also developed a machine for grinding crankshaft thrust-walls, flange face, pilot diameters, and reluctor ring all in one machine.]]> http://drishtikona.com/archives/machining/000515.php/feed/