ARNOLD AIR FORCE BASE, Tenn. -- Precision machinists in the Arnold Air Force Base Model and Machine Shop wasted no time getting their new vertical turning center up and running.
Since installation was completed shortly after the calendar rolled into 2024, the machine has operated virtually nonstop both day and night.
The vertical turning center, or VTC, operates similarly to a wood lathe but, rather than items to be cut being positioned horizontally, items are situated vertically on a rotating table within the machine chamber. As the piece rotates, carbide blades within the chamber are used to mill and grind, essentially “peeling” off metal until the piece is formed into the desired shape.
The VTC was needed to accelerate the fabrication of various-sized nozzles to be installed in a wind tunnel at Arnold AFB, headquarters of Arnold Engineering Development Complex.
“On this project, we were able to compress the schedule at least in half,” said Brad Reid, manufacturing services deputy manager for the AEDC Test Operations and Sustainment contractor. “We’re running two machines around the clock on it.”
A similar machine called a vertical turning lathe was already in operation in the Model Shop. Much like the new VTC, this in-demand lathe is in near-constant use. At the time those in the Model Shop were tasked with the project, the lathe was the only machine at Arnold with the capacity to accommodate the creation of the large nozzles.
Although the lathe was operating around the clock, those in the wind tunnel overseeing the project recognized the need for an even more expeditious fabrication of the nozzles. They reached out to team members in the Model Shop to see how this could be accomplished.
“They had a tight schedule, and we told them, ‘This is how long it will take us,’” Reid said. “They said, ‘What do you need to make it faster?’ We said, ‘Another machine,’ and they came through.”
Following this discussion, the nozzle project team opted to move forward with the purchase of the VTC to allow Model Shop personnel to double their efforts. Once this decision was made, the Model Shop team worked closely with Air Force Lead Mark Grantham in purchasing the equipment capable of machining the nozzle sections.
“We have a very short deadline for providing these new nozzles,” said Air Force Project Manager Lauren Holcomb. “It would not be possible to provide them within the required timeframe without the addition of this second machine. The second machine accelerates our schedule by allowing multiple nozzle sections to be machined at once, and it reduces schedule risk by mitigating schedule conflicts among other high-priority projects.”
Reid expressed his appreciation for the move, adding the equipment can be used in the future to support various projects and customers.
“We got this because our current lathe stays continuously busy,” Reid said. “As soon as one job finishes, another is waiting in line, and we even have to go two shifts on it a lot of times just to keep up.
“This [vertical turning center] is going to alleviate a lot of our backlog problems.”
The more-than-40-ton VTC arrived at Arnold in November, and installation began the following month. Special equipment was needed to transport the machine into the Model Shop. A large hole measuring approximately 20 feet long, 12 feet wide and 8 feet deep was cut into the concrete floor of the shop. After this cut was backfilled and compacted, isolation pads to reduce equipment vibration were placed within. The VTC was then situated atop these pads.
Once the machine was in place, the machinists who would be operating it received training to familiarize themselves with the VTC. Although similar to the vertical turning lathe, the VTC features updated technology, such as a probe capable of providing a precise measurement of the part inside the machine.
Precision Machinist Leadman and AEDC Fellow Norman Smith lauded those on his crew who offered to operate the VTC and their engagement throughout the process of learning the new equipment.
“They’ve really stepped up and just took ownership of the machine, and they figured it out,” he said.
The VTC features a 65-inch diameter table on which items to be shaped are placed. Thus far, the heaviest piece fabricated in the new machine weighed around 4,400 pounds before cutting began, and the equipment has been used to form wind tunnel nozzles of various sizes to represent different Mach numbers.
Although Model Shop personnel explored outsourcing the fabrication of the nozzles, which would allowed the team at Arnold to seek bids for the work from other pre-approved shops across the country, it was decided against due to the amount of time the process would have taken because there were a limited number of shops that possess equipment large enough to make the nozzles. The VTC will allow the nozzle project to be completed in-house and, as Arnold AFB Precision Machine Shop Superintendent Bob Williams reiterated, will continue to benefit Arnold going forward.
“This will support AEDC and customers in the future,” Williams said.