ARNOLD AIR FORCE BASE, Tenn. – It doesn’t slice. It doesn’t dice.
It doesn’t have the stain-fighting power to make your whites whiter and your brights brighter. It won’t make you look 10 years younger or give you six-pack abs.It won’t keep your boat with the screen door bottom from sinking.
Still, James “Trapper” Landon’s recent invention has been deemed an overwhelming success, as the innovative approach has transformed an important, yet laborious, task assigned to several machinists in the Arnold Air Force Base Model and Machine Shop. The device has simultaneously boosted efficiency and reduced injury risk. An arduous job that once had to be performed manually can now be completed almost entirely with the press of a switch.
According to those in the shop, the lapping process at Arnold has never been faster or safer thanks to the Trapper Lapper 5000.
The Trapper Lapper 5000 has been in use for several weeks in the Model and Machine Shop. When the mechanism was first implemented, Landon, an inside machinist who has worked at Arnold for 14 years, said word of his creation spread quickly, prompting fellow craftsmen in the shop to stop by and get a look at the Trapper Lapper 5000 in action.
“There has been a bunch of people to come out here and say, ‘We’ve heard about the Trapper Lapper,’” he said.
The development of the Trapper Lapper 5000 began with an assignment. Landon, fellow Inside Machinist Ronnie Matlock and Outside Machinist Joel Sizemore were tasked with assisting in the rebuild of a large compressor rotor used by a test facility at Arnold. It would be the responsibility of the trio to individually lap the numerous sockets found on the cylindrical rotor.
Lapping is done to ensure the blades seen on the outside of the rotor maintain optimal contact with the rotor itself. Before a blade is bolted to the rotor, the sides of each socket must be formed so that they match up with the blade stub shaft, which is the portion inserted into the socket.
To accomplish this, the stub shaft of each blade is placed in its assigned socket. A brace is placed over top of the blade and the blade is then slowly turned. Through this process, the blade stub shaft will gradually resurface the sides of each socket allowing the blade to fit snugly within.
Because the compressor rotor operates at several thousand rotations per minute, a high level of contact between the blades and rotor is required to eliminate any vibration. The goal is for each blade to maintain a minimum of 90 percent contact.
Initially, the machinists relied upon good, old-fashioned elbow grease to complete the lapping. A small metal crank was placed over the blade and atop the brace, and the crank was turned by hand.
Landon discovered early on that the lapping would be no easy feat.
“I noticed that first hole I worked on, I know I turned it 900 times and I wasn’t even close,” Landon said.
Yet the machinists continued to turn. And turn. And turn.
It wasn’t long before all that turning began to take its toll. Sizemore sought ways to alleviate backaches. Landon said he started experiencing “heavy arms” and pain underneath his shoulder blades.
“That started happening, and I said, ‘There’s got to be a better way,’” Landon said. “So I was sitting there looking at the compressor, and I thought, ‘If there was only a way I could reach down in there and turn that right there where it needs to be, just like the manual thing, but with a drill or something.’”
Thoughts of making the lapping process easier even found their way into Landon’s subconscious.
“I actually had a dream about this crazy thing,” he said. “A dream doesn’t last 5 seconds, but it just kept recurring in my sleep.”
But, as Landon said: “You run into a problem, and you’re either stuck in the mud or you’ve got to do something.” It was time for action.
Landon was given permission by Precision Machine Shop Superintendent Bob Williams to work on his idea. He found within the Model and Machine Shop just what he needed to get started on the Trapper Lapper 5000 – a flex-arm tapping machine.
“One day I walked by that dang tapping thing and went, ‘That’ll work,’” Landon said.
A tapping machine is similar to a drill. Both are used to bore holes into materials such as wood and metal via bits attached to and spun by the device. The two differ in that drilling is done when a hole with smooth sides is wanted, whereas tapping is used to create threads along the sides of the hole.
After borrowing the tapping machine, Landon moved on to the next step of the development process – the construction of a fixture that could be attached to the rotating portion of the tapping machine while holding the rotor blade in place. He crafted a metal “cage” to go over top of the blade and sit atop the brace over the socket. The portion of the attachment used to hold the blade mirrored the design of the manual crank.
Landon said he can’t take full credit for the Trapper Lapper 5000, as the input of his fellow machinists helped bring the device to fruition.
“As we’ve gone along, we’ve all had good ideas on it,” Landon said. “Everybody played a big part in it.”
Landon found his first design didn’t work as well as he had planned. The cage was “walking off” the center of the brace as it rotated which would cause the socket to be more egg-shaped than round, thus prohibiting the desired contact between the blades and rotor. Matlock suggested to Landon a modification to the prototype – changing the shape of the cage from a “half-moon” to a full circle. With that, the problem was solved.
“The second one was the one that really took off,” Landon said. “It started running true, and it’s still running true.”
The Trapper Lapper 5000 was able to quickly win over its skeptics. Landon said Sizemore initially preferred the old way of doing the job.
“Joel, he didn’t even want to fool with it,” Landon said. “He said, ‘I’m fine, I’m fine.’”
That mindset changed the first time Sizemore tried the Trapper Lapper 5000.
“Before I knew it, he started liking it and he just took off with it,” Landon said. “He was just knocking them out left and right.”
Sizemore even offered his own suggestions, such as joining Matlock in recommending the shape change and cutting grooves into the brace to allow powerful magnets to more securely hold it in place.
Landon’s first cage was 6 inches tall and is used to “lap in” smaller rotor blades. He has since constructed a 9-inch cage for the larger blades.
A third Trapper Lapper 5000 was built as a backup option by Inside Machinist Michael Simpson so that two systems can be used at the same time.
Between the compressor rotor on which the machinists are currently working and the rebuild of a backup rotor, there were more than 380 sockets that had to be individually lapped. Before the advent of the Trapper Lapper 5000, the machinists were able to complete the lapping of around four sockets each day. Now, they are averaging the daily completion of around eight.
“This is quiet. It’s safe. It’s efficient. It’s ergonomic,” Precision Machinist Planner Danny Owens said of the Trapper Lapper 5000 method.
And Owens knows all about the impact the manual lapping process can have on the body. He previously worked as a machinist in the Model and Machine Shop and once performed the manual lapping of rotor sockets.
With each rotor rebuild the shop has completed over the years, steps have been taken to make the process easier. Owens said the creation of the Trapper Lapper 5000 was the next step in this evolution.
“It’s just been a progression over a five-year period,” he said.
Williams said that he relies upon the expertise and problem-solving ingenuity of the craftsmen in the Model and Machine Shop, adding ideas and suggestions to improve processes are encouraged and they may benefit Arnold AFB as a whole.
“That’s one thing we try to do here at the shop is encourage everybody to come up with ideas and try to change things to make it better for everybody and improve efficiency,” he said.
Innovation is important at Arnold and is a key focus in the U.S. Air Force Vision. From the start, the Air Force has innovated itself into a global projection of military power through air, space and cyberspace. The Air Force maintains its distinction as the world’s preeminent force in these three areas by maintaining its objective of global vigilance, reach and power and remaining true to its vision statement: “The World’s Greatest Air Force – Powered by Airmen, Fueled by Innovation.”
“When it comes to innovation, we need to think big, start small and scale fast,” Air Force Chief of Staff Gen. David L. Goldfein said when offering his perspective on innovation to Air Force Materiel Command.
David Miller, Technology Development Group Manager for the Test Operations and Sustainment contractor at Arnold AFB, previously said innovative approaches occur across AEDC mission areas.
“Innovations have run the entire gamut of technical competencies and all have provided measurable and objective enhancements to mission accomplishment,” he said. “Innovative approaches to logistics, test support, manufacturing, engineering solutions and information technologies have dramatically enhanced test efficiency and decreased mission risks.”
And Landon is open to suggestions on ways to improve the Trapper Lapper 5000.
“I’m sure somebody will come along and say, ‘Hey, I’ve got a better idea.’ And that’s fine,” he said.