Selway Article: U.S. Manufacturing is On the Rise

How Matsuura palletized machining helps a Washington manufacturer increase spindle utilization, expand 5-Axis capacity, and keep production moving unattended.

For HEI Precision in Bellingham, Washington, automation isn't simply about replacing labor. It's about getting more productive hours from every machine on the floor. The AS9100-certified, ITAR-registered contract manufacturer specializes in production work ranging from hundreds to hundreds of thousands of parts annually. As production requirements increased, HEI began investing in different forms of automation to increase capacity and make better use of its people, machines, and available floor space.

One of its most successful investments turned out to be palletized machining.

In 2022, increased production requirements for a family of shock absorber components led HEI to look for additional horizontal machining capacity. Rather than adding a standalone machine, the company selected a Matsuura H.Plus-300 with 15-pallet automation and a 330-tool magazine.

The integrated design was an important part of the decision. Machine, pallet automation, controls, service, and training are all part of one Matsuura system—simplifying ownership and avoiding many of the integration challenges that can come with combining equipment from multiple suppliers. The compact footprint offered another advantage. HEI could add significant automated production capacity without dedicating valuable floor space to a large linear pallet system.

As HEI President Mark Holz explained to Modern Machine Shop, the amount of production available from such a compact footprint was impressive.

HEI takes full advantage of the H.Plus-300's tombstone workholding to increase the number of parts that can be machined during each cycle.

The company starts with raw tombstone castings and machines the locating surfaces and mounting patterns directly on the Matsuura. This gives HEI the accuracy and flexibility to configure vises in multiple orientations while maintaining precise alignment.

For demanding aerospace and defense work, HEI can also use in-process probing to verify critical features during machining. If a measured feature falls outside specification, production can be stopped before additional parts are affected.

The result is a combination of automation, workholding, and process control designed to keep the spindle producing good parts for longer periods of time.

After seeing the production advantages of palletized machining on the H.Plus-300, HEI expanded the concept.

As increasingly complex work entered the shop, the company added two Matsuura MAM72-35V 5-Axis machining centers, each equipped with 32-pallet automation and 330-tool capacity.

The MAM72 systems allow HEI to machine complex components complete—or nearly complete—in fewer setups while extending unattended production.

Much of HEI's work uses 3+2 machining, allowing prismatic components such as manifolds to be positioned for access to multiple faces and difficult-angle features. A combination of vises, pyramid fixtures, and mini tombstones gives the shop flexibility to accommodate a variety of jobs across the pallet system.

The real advantage of pallet automation isn't simply having more pallets. It's what those pallets allow HEI to do with its available spindle time.

While one pallet is inside the machine producing parts, operators can prepare other jobs offline. Programs can be assigned to individual pallets, tooling can remain loaded in the machine, and upcoming work can be staged and ready to run. Redundant tooling supports extended periods of unattended production. At the same time, leaving selected pallet positions available gives HEI the flexibility to introduce prototypes, first articles, or emerging jobs without unnecessarily interrupting established production.

A new job can be machined, removed for inspection or programming adjustments, and replaced by another scheduled pallet—The spindle keeps cutting. And according to Holz, that's where HEI has found some of its strongest returns from automation:

“We have invested heavily in all kinds of automation, but the biggest ROI has come from the most basic — the pallet changers.”— Mark Holz, President, HEI Precision, as quoted by Modern Machine Shop