Motoman finds that producing its own fixtures with a modular approach has greatly improved efficiency.
In the 21st century, robots have become part of our industrialized society, representing to some the imminent obsolescence of man, and to others the dawn of a brave new world of efficiency and productivity. Although today’s robots bare no resemblance to Czech writer Karel Capek’s "humanoid slave" robots, they’re just as emotive and, for many, equally fearsome. Labor leaders resent their introduction to the factory and industrialists see them as the ultimate workers: no coffee breaks, absenteeism or pay disputes. But in reality, robots have turned out to be rather prosaic: neither the universal panacea hoped for by the capitalist, nor the harbinger of mass redundancy feared by the unions. What they are, however, is productivity-enhancing tools for manufacturing companies. They’re typically used in environments where conditions are dirty and/or dangerous, and often used where a job is repetitive and requires little if any discretion.
Motoman's range of robots includes 4- and 6-axis systems with payload capacities from 3 kg up to 400 kg.
Driving for three hours in a raging blizzard through southern Sweden’s almost endless beech forests, we eventually come to the small town of TorsÃ¥s, home of Motoman Robotics Europe AB (ME).
Since 1976, ME has been building robots and multi-axis servo positioners for industrial automation. Its products are used in a wide variety of applications and industries, including automotive, tooling, machine tending, consumer products and process industries. The company’s range of robots includes 4- and 6-axis systems with payload capacities from 3 kg up to 400 kg, and its servo positioners have payload capacities up to an impressive 20,000 kg.
But unlike Capek’s creations, industrial robots are not inherently universal: They need to be customized to the customer’s specific application, and an essential component in the customization process is the design and manufacture of workholding fixtures. Just as the robot application can be diverse and varied, so can the design of the fixture. Motoman sees this as a vital part of its product offering, and a key value-added service to its customers.
“The design and engineering of the fixtures is where we, as an organization, are able to add a lot of value to the solution we supply to the customer,” says Michael Tranberg, ME’s technical manager. “Some of the fixtures are very large and very complex. They need a lot of machining, and almost every one is different in design and function. In the past, we’ve outsourced as much as 90% of this work to our subcontract suppliers.”
For nearly 4 decades, Motoman has been building robots and multi-axis servo positioners for industrial automation.
The predicament faced by ME is the same one faced by manufacturers around the world: As the volume and value of outsourced work increases, so does the long-term strategic importance of the “make-or-buy” decision. A company needs to identify its core competencies – where it can add most value and where it most needs to control cost and quality.
Tranberg explains the thinking at ME. “We decided to be more efficient and reduce our costs by designing and manufacturing more of the fixtures in-house.
“We started with the design,” he explains. “We made an investment in CAD – Catia v5 – before starting to look around for suitable CNC machines. Initially, we went looking for used machines. Then we contacted EDSTRÖMS, the Jönköping-based machine tool distributor, and they introduced us to the Haas range.”
Top of the company’s buying criteria at the time were price and quality. EDSTRÖMS knew that the Haas machines would fit the bill but, as Haas was still relatively new to Sweden, the engineers from Motoman had some concerns.
“EDSTRÖMS provided a demonstration of a Haas vertical machining center,” says Tranberg. ”We were sufficiently impressed to place an order for a VF-4, with an option for a second machine.
“We wanted to try the first machine and feel happy about it before we committed to the second – to alleviate any concerns regarding reliability, spares and back-up. We were very satisfied. The machine was up and running before the summer vacation last year, which gave us the chance to also evaluate the prismatic machining module of the Catia CAD system.”
Just after the summer, the company took the option on the second VF-4; shortly after that, they placed a third order for another machine.
As the volume of ME’s fixture design and engineering projects has increased, so the company has started to look at ways in which the manufacturing process can be optimized for speed and efficiency. One way to do so is to take a modular approach to the design, so that major components can be used across a wide range of different size fixtures and robot applications.
Motoman's employees have found the Haas CNC to be very user friendly.
“To reduce manufacturing costs, we felt it was important to take a modular approach to fixture design,” explains Tranberg. “That is, if we could create standard shapes, and in a very simple way change dimensions according to the size of the fixture we were building, we could reduce the number of programs and the number of different fixture parts we were making. We could also save a lot in the design, and the non-machining down-time of the machines.”
“We think we have a good system. We’re happy with the CAD and the CAM software, we have the interface with the machines, and our design people have embraced the modular concept. It’s all systems go!”
The engineers at ME are still doing a lot of programming at the machine control. Tranberg is particularly complimentary when it comes to the Haas CNC.
“The guys on the shop floor have told us that the Haas CNC is very user friendly: There are lots of time-saving features, and the code it generates is very similar to other systems. They also like the fact that the education period for the control is so short; they learn it very quickly.”
The company is currently conducting studies with the help of EDSTRÖMS to make the overall machining processes more efficient. As Tranberg explains, the key is to maintain the flexibility of the Haas machines, whilst simultaneously reducing set-up times.
“We don’t machine batches,” he says. “The parts we make in each setup are almost always quite different. Some of them are very large components, which is why we went for the Haas VF-4 and its long table (1321 mm), and some of them take much longer than others. It makes scheduling very tricky.”
The new, modular approach at ME will probably see the current two shifts a day (16 hours) increased to three as more of the fixture work is brought back in-house.
“We’re planning to machine more of the manipulator parts in-house, as well,” say Tranberg. “The main problem we face is the same as that faced by companies all over the word. Namely, finding skilled people who can do the work.”
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