Multi-Tasking: Is it Right for Your Shop?
- October 14, 2001
For manufacturers looking to achieve that competitive edge, you can do no better than a multi-tasking machine. They eliminate the need for separate milling and turning machines, multiple set-ups and, most importantly, they improve productivity.
While multi-tasking offers manufacturers a machining panacea, before you make the investment in such a machine - prices can range from $500,000 to more than $1 million depending on the type of machine - there are four key factors you should consider, advise suppliers who spoke with Shop Metalworking Technology.
One of the first hurdles is to narrow down the selection.
"There are many different types of multi-tasking machines and what I see is that in many instances customers have purchased the wrong type of multi-tasking machine for the type of work that they're doing," says Vince D'Alessio, executive vice president of Elliott Matsuura Canada, Oavkille, ON, which distributes a machine tools from several suppliers including Matsuura, Nakamura-Tome and AgieCharmilles.
Suppliers readily admit that multi-tasking introduces a higher level of complexity on the shop floor. Some manufacturers are intimidated by the technology. It's the reason that builders like Mazak have tried to address this complexity. While most builders today offer multi-tasking machines, Mazak stands out for the variety of multi-tasking machines it offers customers and how it presents them to the marketplace.
The company has created five levels of automation to describe its multi-tasking machines. Level one is the classic live tool lathe which offers drilling and some milling capabilities. Level two introduces a Y axis for off-centre drilling applications. Level three machines feature a milling spindle with B axis machining capability that replaces the turret, allowing for heavier milling capabilities not typically possible on a simple live tool lathe. The spindle also allows for tool changers and tool magazines, typically limited on a turret. Level 4 machines offer full five axis cutting and level 5 machines are typically customized units that offer specialized machining processes such as grinding, honing, polishing and gear cutting.
Multi-tasking is growing in Canada, says Rick Ware, vice president of sales and marketing for Mazak Corp., Florence, KY. Indeed, Mazak Canada's largest order in its history was a group of multi-tasking machines sold to a manufacturer in Western Canada servicing the oilfield industry.
"The predominant machine we sold to this company is the QTN-450MY, the largest of Mazak's Quick Turn series multi-tasking machines. It falls between our Level two and Level Three machines because of its capabilities and it's a popular machine for the oildfield industry because of its ability to securely hold and machine large and long parts."
Four Considerations Before You Purchase Your Multi-Tasking Machine
- Know your machining parameters and purchase a machine to match them.
Seems simple enough, but Elliott Matsuura's Vince D'Alessio, says that not everyone matches their machining parameters to the machine they need. Instead, they often will purchase a machine they want based on the features and capabilities they like.
"I've been in shops with multi-tasking machines that have B axis versus a turret. There seems to be a big push among manufacturers to purchase multi-tasking machines with B axis capability and automatic tool changers. But I think there are a lot of applications where people are focusing on just having the tool changer on the machine and forgetting about the production side of what they're doing."
Other suppliers concur with D'Alessio and say manufacturers have to look at their production and decide on whether they need a multi-tasking machine with a tool spindle and automatic tool changer, a machine with multiple turrets or a unit that combines a spindle and a turret.
"We offer all of these machine types, but a lot of times we walk into shops after the fact and the manufacturer has purchased a plain Jane tool changer machine," explains D'Alessio. "But if a manufacturer is doing production work, he may have purchased the wrong machine. Change over times may have gone down, but if that manufacturer was making 100 pieces and cycle time has gone from 15 minutes to 30 minutes, what has he gained?"
- Choose Your Machine Supplier Wisely.
There are not only many types of multi-tasking machines, there are a lot of builders offering them too and knowing which builder has the best package for your shop can be a challenge. A company's reputation is a good start, but more importantly, you need to ensure that the support network - technicians and other support staff from the builder or the distributor - is capable of supporting the complex technology that is multi-tasking.
"We recommend that customers select the right machinists for training on multi-tasking and by that I mean people with some machining centre experience versus just turning experience who could better grasp machining with five to nine axis motions," says Mazak's Rick Ware. "That's one main reason we built this Technology Centre [at the company's North American headquarters in Florence, KY]. It is for customers to come and get the proper training on the different types of multi-tasking so we can help them optimize their processes."
Elliott-Matsuura's D'Alessio couldn't agree more. Multi-tasking machines have changed the relationship between customers and machine tool suppliers.
"In the past you would sell a machine, spend a day with the customer for training and wouldn't hear back from the customer until there was a breakdown. Today, it takes a week to install some of the more sophisticated multi-tasking machines, six weeks to train and then you're hearing from the customers for the next six months; it's ongoing training because it is more complex machining."
- Understand the inherent problems with simultaneous multi-axis machining and how to address them.
There are multi-tasking machines in the market from suppliers such as DMG, Okuma, Mazak, Mori Seiki, Nakamura-Tome and Matsuura with multiple axis machining capabilities, some with up to 12 axes.
"The amount of work going on at the same time is so much greater than in a machining centre and if you have the right type of work, nothing is going to beat this machine from a cycle point of view," says D'Alessio.
When you have multiple processes and components such as spindles and turrets working simultaneously, one of the biggest concerns is interference that impact the part and machine.
"The more sophisticated the part gets, the more tools you're going to need and when you have many tools loaded up on one turret, it can get out of hand with interference, especially if you have a round or octagonal turret with tools coming out," explains Mazak's Rick Ware. "Of coure the bigger the tools, the higher the likelihood of interference. "That's why in some of machines we designed them so the machine takes the tools off the turret and puts them on the tool changer, which minimizes the interference as much as possible."
- Consider the software required to support multi-tasking
Of course the other key way to avoid interference or collisions is to have the right software - CAD/CAM and virtual machining simulation or collision avoidance programs. According to some suppliers, CAD CAM suppliers have, to date, not bee able to provide what D'Alessio describes as "bullet-proof solutions for multi-tasking" partly because there are so many variations of multi-tasking machines on the market. It's one reason why most of the major multi-tasking machine tool builders have come out with their own software, such as Mazak's Mazatrol and Matrix programs, to Nakamura-Tome's NT software programs and Okuma's well-known THINC.
Multi-tasking can be the answer for your machining challenges, but suppliers urge manufacturers to keep in mind the considerations for multi-tasking before they make the huge investment in these machines.