Automation Breakthroughs Revolutionize Precision Machining for Complex Parts

Machine shops around the world are always looking for ways to make production better, faster and ideally easier. With new automation solutions coming to market each year, cobots and robots can help many shops achieve these gains. But what about precision machining where parts are smaller than the chips being cut and require extreme care to handle?

Marubeni Citizen-Cincom (MCC) has worked with customers in some of the most demanding industries to design and build systems and solutions they didn’t even know were possible.

With a deep history in the Swiss-type turning centers, MCC has expanded over the years to include fixed head automatic lathes from Miyano, adding more options for customers who need the very best precision manufacturing equipment available.

But MCC doesn’t only sell and service machines, they have built an entire department around automation and custom solutions. Company President and COO Brian Such says it is hard for the company even to advertise its full range of solutions because each is unique. “Bring us your problems and talk about what solutions you are seeking and we can make it happen. Put us to the task.” It is common for MCC customers to purchase an automation cell with a Citizen CAV magazine bar loader to continuously feed the machine, but MCC offers so much more.

Swiss-type turning centers have long been used to manufacture highly precise components for watches and other delicate electronics. Today they are being used heavily to create parts for medical implants, including tiny bone screws that can be smaller than the chips the machine is cutting away. Magazine bar loaders allow many parts to come off the machine with hours of continuous runtime, but for some customers, Such says their parts are so delicate they can’t touch each other or be touched by a human hand.

“One of our customers manufactures bone screws that are 1/8- to 1/4-in. and 1- to 3-in. long but the parts can’t touch each other,” Such says. “We’ve designed and manufactured a bone-screw unloading devices with robotic fingers that can remove parts from the machine without dropping them, pass them to another gripper that will take the screw to clean it, measure it and send adjustments back to the machine or even stop the machine if it’s out of spec. The gripper then places each individual screw into individual dishes of a tray, ensuring they don’t touch each other.”

In addition to bone screws, some of MCC’s customers manufacture incredibly small parts, 0.3mm or 0.012-in. which is the equivalent of four human hairs in width. Parts this small are used in surgically implantable devices for heart surgery, hearing implants and other applications that the customer keeps confidential.

Such said the customer came to them and said they were having great success manufacturing the parts, but needed to catch and collect these tiny parts without losing them among the chips. The MCC team developed a device called a vacuum extractor that sucks the part out of the machine and machining area and transports it to the rear of the machine where it is individually trayed.

MCC took the customer’s existing packaging system and incorporated it into their machines automating this process and addressing multiple challenges with one well-designed solution. Once this solution was designed, it’s easy now for MCC to adapt it to other customer needs for their unique applications.

“We can teach our machines to get four to eight hours of unattended operation, but someone has to manually check and ensure there are no problems. With vacuum extraction, we can put the number of parts in one tray that the customer desires. An operator can then check the parts in one of the trays within the set and if it’s within spec they know the whole run was in spec and is good. “This creates an easy way for customers to sort high-production tiny parts using this servo tray extraction, ensuring good parts every time.”

What about the robots?

Robots, cobots and other automation are a big topic among manufacturers today, but they can be cumbersome and create obstacles that workers have to maneuver around to do their jobs. Such said with the Miyano lathes they are often manufacturing parts 42 to 65 mm. Operators and automation vendors place a simple cobot in front of the machines to load and unload parts, but if it needs set up or adjustments, the operator has to either work around the robot or move it, creating unnecessary down time if the robots need to be moved to gain access to the machine.

MCC recognized that not only was this an annoyance for operators but was potentially unsafe so they put the engineering team to work and found a way to put the robot on top of the machine, moving it out of the way of the operator. “By putting the robot on top of the lathe, operators can take parts for cleaning or measurement or to quality check. They can palletize their systems and use an elevator to move trays up and down to the operator without being an obstacle in their workspace,” says Such.

Addressing tooling challenges

Such shared a unique challenge from a customer using a Swiss-type machine. For a number of years MCC Swiss-type machines have had lasers available on machine for cutting fine details on parts. One customer was running Part A, then Part B then Part C, with Part C requiring the laser, followed by assembly and welding the parts together. The customer wanted to run the part in the machine in one set up and introduce a tube to be welded all in the same operation. MCC was able to build in automation that loads small 1 to 2 mm very fragile tubes into the machine.

The part can now go through the first operation, pass to a holding area and while the next operation runs. The parts can then be brought back and welded in the same setup all inside the Swiss-type machine the customer was already running, creating an in-situ operation that creates a total manufacturing solution for the client.

Most common Swiss-type machines have four live tools and four tools on the backside that are live and static. To add more tooling, customers have to size up to larger machines that can accommodate larger tool holders, even just to add one additional tool. While they offer more functions, the larger machines cost more and may be more than what the customer needs most of the time.

 To address this issue, the engineering team at MCC put their heads together and came up with what they call a tandem live tool. “This tandem holder

allows two live tools in one slot, doubling the active tools in the holder,” Such says. The tools are mounted on top of each other creating two rows. “One customer had a need and now this is a standard toolholder for us.”

This innovation led to others for MCC. “Another example was a customer making bone screws,” Such says. “Bone screw threads are cut by thread whirling, and for many years we had to use third-party live tooling heads made to fit inside our machines. They move very fast, are constantly cycling between on and off and aren’t ideally designed for our machines. We took this to task and designed our own. The MCC whirling head is larger, more rigid and can handle the high speeds required.”

But like most things, change came to the bone screw market and customers now required two different threads on one screw. MCC used its own whirling head and a third-party one to accommodate this, until they developed and introduced a new tandem thread whirling head that utilizes B-axis movement to get the angles required for the secondary threads.

“Sometimes we get requests for unique tooling holders that the rest of the world won’t use, that could be unique to solve one customer’s problem,” Such said, “And we work with our customers, our suppliers and our own engineering and automation teams to come up with a solution. Often this is with third-party high-speed spindles. However, a number of years ago we worked with NSK to develop an 80,000 rpm spindle custom built for us for our machines, with exclusive sales available through MCC, that allows for the precise deep-hole drilling many of our customer applications require. We can put the spindle in four different places in the machine – front cross, back cross, on another gangplate or a back gangplate,” Such continued. “This is a modular solution. In the past the spindles may have been too large to fit in customers’ existing machines, forcing them to buy a larger machine. Working with NSK we made a spindle holder for the NSK spindle that is a significantly lower cost alternative to buying an entirely new machine – thousands of dollars instead of hundreds of thousands of dollars,” Such says. This specialized, one-off type solution developed for one customer often ends up being a marketable solution for other customers that MCC serves.

Small but mighty

Marubeni Citizen-Cincom is a fully owned subsidiary of Marubeni Corporation and Citizen Machinery Company that offers sales, service and engineering solutions for customers. Since its founding 40 years ago, MCC has advanced the growth of Citizen Numerically Controlled Machines (CINCOM) and Miyano high-precision fixed head lathes across North and Central America.

The addition of Miyano expanded MCC’s line to offer manufacturing solutions for 2- to 65-mm bar applications. Such, who started with the company while he was a student says that the company thrives on solving problems for customers. No problem is too big or too small for the team. “Put us to the task,” he says. With an integrated team of engineers and designers the team and business thrive on developing unique and affordable solutions for problems customers may not even know they have. Reach out to MCC to help you solve your next Swiss-type or lathe machine challenge.