Digital Manufacturing Company Delivers the High-Mix/Low-Volume Jobs ASAP with Multi-Tasking Machines

Manufacturers typically utilize automation technology to reduce lead times for long runs of identical parts. On the other hand, custom, complex, short-run jobs like those in prototyping environments are not usually candidates for traditional automation concepts. However, a Maple Plain, Minn., company has overcome this production challenge with a unique strategy. Protolabs combines a start-to-finish digital thread with a group of identical, flexible, multi-tasking machine tools to not only automate machining, but also slash production lead times for small job lot sizes from weeks to days, and in some cases down to just hours.

Protolabs – a leading global source for machining, molding, 3D printing, and sheet metal services – has employed innovative technology and strategies from its early days. When seeking a better way to produce injection molded parts, software engineer and company founder Larry Lukis created a software-based system that accepts a customer CAD model then applies the data throughout the manufacturing process. “From the beginning, if he couldn’t do it in a digitized way, he didn’t do it,” said Mike Kenison, Protolabs vice president and general manager, Americas. Today, “We are faster than everybody else,” he said, adding that digitizing the entire manufacturing data flow from initial order to completed part results in lower non-recurring costs for the first-part process compared to traditional manufacturers.

Protolabs serves a challenging segment of machining production. Scott Pedersen, director of manufacturing operations, said of its machining service, “We are a high-mix, low-volume producer. Lot sizes are small. Typically they range from one to 200 machined pieces. The vast majority are less than 100 and many are one to ten parts.”

To maximize its competitiveness, Protolabs has developed ways to standardize and accelerate precision low-volume work. The strategies are based on efficiently utilizing a group of identical machine tools. “That makes us very flexible,” Pedersen said. “If we get an order that requires more than one machine, we might run it on two machines instead of one. At other times, every machine may be running a different part. We never know what orders are going to come in, so we always have extra machines and extra capacity available. That’s how we make this work.”

Production forecasting can be more of an art than a science at Protolabs. The company deals with tens of thousands of different customers yearly, Kenison said. The average machining order is three parts (molding orders in the thousands and tens of thousands), resulting in the milling and turning of thousands of different geometries per year. “There is a need to understand what the flow will be when you are dealing with that many customers.” However, despite the large variety of customers and parts, workflow is well controlled. Pedersen said, “I don’t want to say it is super steady, but we are set up to handle fluctuations in volume. We never know what we are going to get for an order and we do our best to be prepared.”

Regarding the choice of manufacturing equipment to carry out the company’s strategies, Protolabs’ CNC machining production floors consist primarily of vertical milling machines and standard turning centers. When management saw a need to boost turning capacity, the company added multitasking machines. The multitasking machines’ milling capability gave Protolabs “flexibility that enables us to cut every part for every customer,” manufacturing engineer Dan Robinson said. “Give me any geometry and I’ll tell you I can cut it. The multitasking machines increase our flexibility and our ability to yes more often to the variety and complexity of the jobs that come in.”

To help carry out its low-volume, high-mix, fast turnaround strategies, Protolabs acquired compact Mazak INTEGREX i-100 BARTAC-S Multi-Tasking machines. Each machine has two turning spindles and a milling spindle that together enable full 5-axis machining and Done In One part processing – the ability to machine complex parts in one fixturing. The machines also feature intelligent bar loader systems.

A 4.4 in. (111mm) main spindle bore allows Protolabs to process parts from bar material up to 4 in. (101mm) in diameter, and an automatic tool changer draws from a standard 36-tool magazine. X-, Y-, and Z-axis travels are 17.7 in. (450mm), 8.2 in. (208mm), and 35.5 in. (901mm) respectively, permitting the machine to process a range of part sizes and shapes. The machine’s compact footprint is 127 in. (3,225mm) x 103.8 in. (2,636mm).

“When we choose our manufacturing equipment, it must provide flexibility,” Kenison said. “While we typically deal with high-mix, low-volume, we do have some customers who require higher volumes. As a result, we need to be able to shift back and forth and change over very quickly. It comes down to what our customers want. They always like to have bigger and more complex parts, and we look for technologies like the Mazak Multi-Tasking Machines to fit. We have a robust machine selection process. We look at what we need to get out of our machines, and what their capabilities are. We went with the Mazak machines for their speed, quality, consistency, and ability to produce complex parts.”

All the parts machined on the Multi-Tasking machines are round, and workpiece materials include both hard and soft metals. Bars are changed frequently in response to the material requirements of the various parts.

In addition to CNC machining, Protolabs’ manufacturing services include injection moldmaking and part production, 3D printing, and sheet metal fabrication. The company has production facilities worldwide encompassing over 1 million sq. ft. of manufacturing space. United States operations are in Minnesota, New Hampshire, and North Carolina. Facilities also are located overseas in England, Germany, and Japan. Company-wide employment is approximately 2,500, with nearly half of those employees located in Minnesota.

A recent addition to Protolabs’ ability to serve widely varying customer needs was its early 2021 acquisition of 3D Hubs, Inc. (now just called Hubs), a leading online manufacturing platform that provides on-demand access to a global network of approximately 240 premium manufacturing partners. The acquisition enables the company to expand its services beyond its in-house capabilities. “It makes us a one-stop-shop for our customers,” Kenison said. “If their part doesn’t match our in-house manufacturing services, we can still provide the part. We believe customers will come to us more often if they don’t have to try and pick and choose among other vendors to get their parts done.”

Another customer-focused initiative was Protolabs’ 2021 release of its revamped interactive digital quoting platform that features a more modern interface, seamless navigation, interactive manufacturing analysis, and real-time pricing. It enables customers to upload a CAD model to protolabs.com, choose material and finishing options for the parts, learn how that choice impacts part lead time and manufacturability, before ordering the parts. Users can work with the system on their own, and Protolabs engineers, as well chat functionality, are available to assist with the process.

Pedersen pointed out that Protolabs’ services directly accelerates its customers’ product development efforts. “We deliver good parts, reliably and quickly,” he said. “Because our delivery is so fast, our customers—our partners—can iterate designs and develop parts faster. If a design has 12 parts, and the longest lead time on one of the parts from another manufacturer is 12 weeks, it will take 12 weeks to get that iteration of the design. If Protolabs can do those 12 parts in 7 days, the iteration time becomes only 7 days. Our focus on customer needs, our use of technology like the Mazak Multi-Tasking machines, our overall digitization strategy, and our reputation for dependability keeps our customers working with us.”