CNC machining centers continue to grow in popularity due to their flexibility in applications and the ability to process multiple materials, including composite panels, solid wood, plastics and other non-ferrous materials.
The trend toward mass customization is also fueling this demand. “Very few companies these days produce huge production quantities anymore, resulting in the need for flexible, easy to set up and changeover CNC machines,” said Jeff Conger, Weeke product manager at Stiles Machinery Inc.
Bill Blackmon, Busellato product manager for Casadei-Busellato, agreed. “The economic downturn has forced more and more companies to accept jobs that involve smaller and smaller quantities or custom products. CNC machining centers are essential to producing these products with the short lead times, high quality and lowest cost demanded by today’s customer,” he said.
“Machining centers capable of performing multiple operations on the workpiece are the best way to handle the smaller batch sizes associated with mass customization,” agreed Larry Tolbert, sales representative for Solid Wood Systems. “It becomes very inefficient to move parts between various machines, adding additional setups at each machine,” he said.
Michael Cassell, North American CNC product manager at Holz-Her US also noted, “The repeatability, reduced set-up time, the ability of the machine to run in pendulum process and the parametric capability of software are solid reasons for the use of CNC machining centers for customized processing.”
“The trend toward just-in-time manufacturing comes directly from consumer demand for custom products,” added Cesare Magnani, sales manager at Biesse America. “Due to their great flexibility, efficiency and precise quality machining in manufacturing custom products, CNC machining centers present the perfect answer to the manufacturing challenges that just-in-time production brings into factories. More and more manufacturers are looking to the CNC to replace traditional manufacturing solutions that were designed for high-volume standardized productions,” Magnani said.
“CNC machines have always been the mainstay in flexible production and have been driving this trend for many years,” said Rob Howell, CNC product manager at SCM Group USA. Shops of all sizes, he added, are buying these versatile machines.
Flexibility with Small Footprint
With both labor and space a premium, flexibility, efficiency and a small footprint are just some the benefits cited with regards to CNC machining centers.
“We see a very significant trend going toward large and small companies alike needing small footprint, rich capability machines that have virtually zero setup,” Conger said. “As lean principles encourage manufacturers to go away from purchasing “monument” pieces of equipment, we see the trend for this to intensify to even greater extents in the future.”
Manufacturing trends also call for lean cells driven by CNC machines with automatic feeding and unloading systems with zero set-up time, both Blackmon and Howell said. Other capabilities Howell noted include intelligence systems, automatic part identification, and automatic tool settings that measure and set coordinates via a touch probe.
“Flexibility can be introduced at several different levels, such as work tables capable of holding different types of components, textures and dimensions, and high capacity tool changers capable of hosting a large range of tooling and aggregates,” added Magnani.
Cassell said, “Larger tool changers, increased use of aggregates, multiple processing zones and extended table lengths are common requests.” Also noted was an increase on clamping options offered.
Pod placement assistance and/or automation also is requested. “Motorized pod and rail systems are essential for producing short-run, variable-sized parts like custom cabinets and outside edge profiling of cabinet doors,” Blackmon added.
More Material Options
In addition to machining variable part sizes, companies today also are faced with a growing need to process a range of media.
“The ability to cut plastics, aluminum, honeycomb composites, etc., and other materials on the same CNC machine you cut wood panels has greatly expanded the capabilities and markets for smaller shops as well as store fixture and millwork companies,” said Howell. “This is where tooling has made great advances.”
Blackmon also noted that when running non-wood materials, flexibility in the feed rates and spindle RPM becomes critical. “Many plastics and non-wood-based composites require a much lower spindle speed than wood-based materials. Spindles do not reach peak power output at lower RPMs, so a spindle that is marginally powerful at its peak RPM may not be powerful enough for plastics and other composites at lower RPMs,” he said.
Along with the increased range of speeds, “Virtually all machine spindles are offered as standard with HSK tool holders providing a much high rate of stiffness. Spindles and tool holders also are available with bi-directional rotation (clockwise-counterclockwise),” Cassell said.
It doesn’t stop with tooling. Magnani and Tolbert noted product manufacturers may be required to equip the CNC machines with options/add-ons, such as an oil mister, if plastics and non-ferrous metals are machined on a regular basis. “Dust collection also needs to be addressed,” Tolbert added.
“Different materials will require a different approach to the dust collection system of the machine. The type of material will have an impact on the type of chips or dust that needs to be removed, as well as the rate of removal necessary,” he said.
“As rapidly changing designs of products force the need for machines to be up to the challenge of cutting these, we are also seeing a large push for machine builders to design equipment that is versatile enough to handle many various substrates,” Conger said.
“The uncertainty that lies in never knowing for sure what jobs they will be required to produce in the future makes for an interesting challenge,” he added.
With the popularity of these CNC workhorses continuing to grow, what’s on the horizon?
“Customers are looking to get a wider range of production from one machine,” Tolbert said. “They also are looking for improvements in safety and self-diagnostics.”
Improved material handling also was noted by many as being on manufacturers’ wish lists.
“Companies have come to the realization that they can purchase the fastest machines in the world to produce their product, but when all this efficiency is lost by not having an adequate means of loading or off loading material it defeats the purpose,” Conger said. “More and more, companies are taking close looks at their process flow and designing workcells that keep the machine producing parts at the highest rate possible,” he said.
“Flexible material handling systems, from elevator type storage systems for panel inventory to short term buffers for WIP, that allow manufacturing efficiency for the machines while sending the right parts to assembly and packaging,” added Howell.
Cassell and Magnani also commented on the need for improved material handling. “Current developments are greatly focused on material handling, automatic load/unload solutions and automatic tool and material identification. These are areas that can provide quick returns in efficiency reducing labor intervention and streamlining production processes. The main applications for automatic material handling are in nested based manufacturing, as well as solid wood applications for doors and windows manufacturing,” Magnani said.
“I do believe the woodworking industry will begin to accept the use of robotics as the metal working industry has,” Cassell added.
“As already mentioned, any feature that provides labor savings is a much more popular topic these days, while processing speed is less important,” Blackmon said. “Another request is for simple machine controls that run on the PC platform, making the machine easily added to the network and providing a familiar interface that makes operator training easy and fast.”
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