Pallets Provoke a State of Flow

In manufacturing, flow usually refers to how material moves through a facility from stock to finished part. But for humans, it refers to a mental state where we become so fully engrossed in an activity (for example making music, reading, playing a sport or writing) that it feels effortless. So, is it possible for a machine shop to experience that type of flow? Kelly Denison, owner and president of Continental Machining Company, thinks so, and he’s striving to reach and maintain this state. “I'm starting to see in our organization, once you get into a flow state, it takes a lot of pressure off,” he says.

On the flip side, when a machine shop isn’t in a state of flow, problems become apparent. When Continental’s quality department was experiencing a backlog, Denison traced the issue back to a lack of machining capacity. A five-axis machining center with a 10-pallet pool restored flow to the shop, enabling it to operate smoothly.

The Best-Kept Secret in Manufacturing

Home to both Sandia National Laboratories and Los Alamos National Laboratory, New Mexico is a hotbed of technological innovation. Continental was founded in Albuquerque in 1965 to serve these R&D labs. The shop has since leveraged its experience with these organizations into work for the aerospace and defense industries, and dabbled in medical and pharmaceutical work as well. “Our customers have told us in the past that we're a best kept secret in the manufacturing space because of the work that we're doing for those national labs,” Denison says. “We really do some high tech, wild stuff.”

Working with these national labs means Continental often deals with prototype parts and low volumes, but Denison says the business thrives on part runs between 20 and 2,000 pieces. In terms of size, he says the company handles smaller parts but specializes in parts the size of a toaster and larger. “Our lathes go all the way up to 72 inches in diameter,” he notes. “We have a number of large mills that have 80-inch travels and things like that.”

The shop presently has 30 machines, primarily a mix of models from Haas and Mori Seiki, though it’s branching out into other brands, including Hwacheon and Matsuura. It added its first five-axis VMC in 2015. “Screw machine salesman always say, once you get one, your customer is going to want to flood you with work, and you're going to want to have more, right?” Denison recounts. “That was my experience with five-axis machining.” The company eventually added two more five-axis VMCs.

Quality Management Is Business Management

According to Denison, Continental’s quality system sets it apart from other shops. “Our quality system was built around AS but we hold ISO, so it's very robust,” he says. This traces back five years when the company overhauled its quality system, and Denison had a revelation. “Any kind of quality system really is not a quality system,” he explains. “It's a business management system.” And as the company’s president and owner, quality starts with him. “When we really stepped into understanding that it's a business management system and not just making sure our parts got out the door good, it really was a game changer for us.”

This shift in perspective led the company to de-emphasize traditional quality KPIs such as rejections and corrective actions. “They didn't give us a whole picture of how the entire system was working,” he explains, in terms of other business success metrics such as throughput, on-time delivery and backlogs. Looking at the business as whole enabled him to see how a backlog of parts creates a bottleneck in the quality department and plays a role in on-time delivery rates. Denison says that this perspective gives him a more complete view of the company’s performance and where to make improvements.

For example, using a Keyence VL series 3D scanner for first-article inspection quickly gives the quality department a heat map to visualize whether parts are within tolerance or spec so it can get parts into production without having to wait for inspection. Once parts are in production, the quality department can focus on more detailed GD&T data because they know the parts are good from the heat map. “That has helped things flow a little better,” he notes.

Pallet pools have also helped take pressure off the quality department so parts can flow through the production process without bottlenecks. “For many years, we looked only at on-time delivery, and were pointing the finger at the back end, that they're the problem not getting parts done fast enough,” He explains. “Really, it's equally a front-end problem.” To solve the problem at the front end, the shop needed to add more machining capacity for both its short-run production and low-volume prototyping work. In mid-2024, Continental added an MX 330 PC10 from Matsuura, a vertical five-axis machining center and pallet system with 10 pallets.

Info Flow

When it came to choosing a palletized machine, what set Matsuura apart for Denison was the integration between the machine tool and pallet pool. “Every other solution that I was looking at had two interfaces: you had the CNC control, and then you had the pallet control,” he says. “On the Matsuuras, everything was all together in one and talked to each other.” This enables information such as tooling data and scheduling to flow seamlessly between the two systems, making implementation and operation easy.

Denison attributes this to the fact that Matsuura makes both machines and pallet pools. He notes that many of the other options he found on the market were machine tools and pallet pools made by separate companies. They could be purchased together through one source, but they weren’t integrated together to the level of the Matsuura system, he says.

Adding Pallets

The MX 330 PC10 wasn’t Continental’s first foray into palletized machining — it already had six four-axis HMCs with two pallets each. “We were used to having a 400- or 500-millimeter pallet. We bolted things down, and that's how we held parts,” Denison explains. “We needed that big platter.” As it started working with five-axis machines, “we realized we were having to stack big things up to be able to clear and get things over,” he continues. “We were running out of pallet space and Z travel.” So, when he started looking into five-axis machines with larger pallet pools, he thought bigger would be better. “But the longer I waited, we got better at five-axis machining and learned different strategies and I realized the smaller pallets are just as useful,” he says.

Specifically, Continental adopted self-centering vises and dovetail workholding, which Denison describes as “a game-changer.” Standardized workholding “takes away problems that come up from having fixtures that you're designing on your own,” he explains.

He also says the shop focused on improving its use of Mastercam for five-axis programming. “The biggest thing was actually utilizing the software and having it do all the work,” he explains. Despite having some of the first CNCs in New Mexico, the shop was still taking a manual approach to programming. “Being a shop that started in 1965, we have old school roots,” he explains. “We were programming just in one plane and then copying and pasting that G code and moving it over into the main program. And then we got proficient at the five-axis stuff where you can't really do that effectively.” Better programs enabled the shop to better use the pallet’s space.  

Continental also made strides in simulation, ensuring that even with the new programming strategies and workholding, its programs are efficient and safe. “We're back plotting and doing things a lot better than we have,” he notes.

By the time Denison pulled the trigger on the Matsuura, the shop had become more efficient at using the five-axis machines to the point that the 125-mm in the MX 330 PC10 were sufficient for Continental’s needs.

Lights On and Lights Out

The MX 330 PC10 also wasn’t Continental’s first experience with automation. The shop has run hundreds of thousands of parts lights out thanks to lathes equipped with bar feeders, parts catchers and conveyors. It also has the six four-axis HMCs with two pallets each. “We were able to do some lights out machining, but a lot of it was with an operator there, loading the pallet and getting it ready while the other one was running,” Denison notes. “This machine with 10 pallets was our first real big jump into that space.” Continental does have a night shift to keep an eye on the MX 330, but according to Denison, “it just runs itself and does its thing.”

However, using these machines for lightly attended shifts has necessitated a change in how the shop approaches running the machine. Denison says the shop’s strategy used to be, “run it ‘til you break the end mill and back it off 10%.” But this strategy isn’t as efficient when people can’t quickly replace broken tools. “It's okay to run the machine at 75% to gain the reliability. You know, this ‘tortoise and the hare’ strategy,” he reflects. “I think a lot of people talk about that, but it really does make a difference in practice. You're gaining so much overnight that it doesn't matter that you backed it off 25%.”

This is where Matsuura’s tool-checking capabilities are a big benefit, Denison says. Operators can load in new tools while the machine is running and use the interface to tell the system to measure the tools before they’re used. “It touches them off with the laser probe, and off to the races they go." If it finds any broken or expired tools, the system moves on to the next job it can complete and notifies the operator to replace the tool.

Mixing the Volumes

During the day, Continental runs high-mix, low-volume jobs on the MX 330 PC10. “We’re setting up one job, getting in an inspection, not having the pressure of this guy standing there, waiting for this part to get checked,” Denison says.

The system, along with the other changes Continental has made, have also reduced cycle times. Denison describes a simple, two-operation job the shop had previously run on a three-axis mill. “We changed the strategy and put it on the Matsuura. It ran lights out the first time we ran the job, and it took us about three, four weeks to run it. Same quantities, same part on the Matsuura, running it lights out and with new strategies, it took us three days.”

Denison is already planning to add more five-axis VMCs with pallet pools to Continental’s shop floor. “Trying to adapt older machines with new technology is a band aid, but it's not the solution,” he explains. “The solution is more of the new normal for us, which is five-axis pallet pools.”