V&M is no stranger to the demands of the precision aerospace industry. Established in 1963, the copmpany serves the top OEMs and Tier 1 suppliers including Boeing, Northrop Grumman and Goodrich Aerostructures, as well as Fuji Heavy Industries and Kawasaki Aerospace division in Japan.

Tough Component

The particular component in this case was an orifice tube that is designed to absorb the first impact of the landing gear as it hits the runway. The orifice tube is a cylinder with slots located in strategic locations. It is controlled with an air cylinder via a metering pin, which acts as an air shock absorber to take the first impact at landing. After that, the hydraulic system takes over. The customer for the component is General Electric.
The tube was produced as part of the new prototype J-UCAS (Joint Unmanned Combat Air Systems) program that was being conducted at Northrop Grumman and led by DARPA (Defense Advanced Research Projects Agency). The program, although still active, is currently going through a restructuring with the U.S. Navy and Air Force taking over the lead. The idea was to develop a single family of weaponized drones operating from land and from carrier decks, backing up and ultimately replacing manned fighter jets.

New Company, New Challenges

V&M was purchased by Dal and Tom Rogers early in 2005, who collectively have more than 80 years experience in the aerospace industry. Dal has owned two other machining companies—Hansen Engineering from 1962-83 and High Tech West, which he sold in 2000 to Integrated Aerospace. However, Dal’s previous companies specialized in airframe components versus the landing gear parts for which V&M is noted.

“This is where Seco Tools has really helped me out,” says Dal Rogers. “I had a bit of a learning curve when I purchased this company, as I previously had been machining a lot more aluminum and titanium. Also, I realized that the V&M shop floor personnel could use some education. Seco Application Specialist Bob Hoggatt approached us regarding training sessions as well as opening our eyes to new applications for our floor that I had only read about previously.”

Taking the Plunge

One of these applications was plunge milling to make a square into a round. This turned out to be an appropriate solution for the company, since it was faced with milling a rectangle instead of a cylinder on the orifice tube.

Plunge milling is a modern, highly productive method of metal removal. It is an axial machining operation performed in a single tool sequence. The tool makes a series of overlapping, (drilling-like) plunges to remove part of a cylindrical plug of material one after another. Due to the increased rigidity of a Z-axis move, the tool can cover a larger cross section of material. The process results in shortened production cycles and increased efficiencies.

While several standard Seco milling cutters can be used for plunge milling, Hoggatt recommended the Seco R220.79-03.00-12 plunge mill cutter. To accomplish this task, V&M ran the 300M forged bar on its Mori Seiki 3-axis mill with a 25-hp spindle at 525 rpm, 20 ipm and .004 stepover.

“It’s an older machine for us, but it’s tried and true and we saved at least 50% machining time over a typical end mill or face mill method,” says Rogers.

V&M was able to rough machine the 8” rectangle to a 4” cylinder in only 2 hours.

Enter grade TP2500

After machining the rectangle into a round, V&M still had the finishing operations to perform. Bob suggested that Rogers try Seco’s recently introduced Duratomic general purpose turning grade TP2500, where the coating is actually manipulated at the atomic level.

Since this was a brand new application, there was no baseline established. The component was run on V&M’s Mighty VT40A Viper Lathe with the TP2500 CNMG 643W-MR7 chipbreaker insert.

“It took a few hours to get the right feeds and speeds, but Bob Hoggatt was right there saying ‘kick it up, kick it up.’ He stayed right with us until things were up and running right.”

Success Right Out of the Box

And they did get it right. With the TP2500 tool, V&M got two passes per edge even with the interrupted cuts.

“We were taking a .200 depth of cut and 2.9 ipm on the first pass to achieve 14.4 cubic inches of material removal per minute and a .310 depth and .4.1 ipm on the second for an amazing 31.2 cubic inches of material removal,” Rogers says. “The cutting length on both passes was 36.5”. Our chip form was perfect and it sounded like a ton of quarters were hitting the floor. Cutting speed was consistent at 196 rpm and 400 sfm on both passes. We were able to kick up the horsepower from 17.1 rpm on the first pass to 37.1 rpm on the second.”

The Seco representative had brought in only four samples of the TP2500 tool to run the nine orifice tube components. The performed so well that V&M didn’t have to make any additional purchases to run the job. Hogatt believes he gained a lot of efficiency by using the 100° side of the corner of the CMNG insert.

“It’s a stronger corner to use as a lead angle, so it thinned the chip better to allow us to go faster.”

“The TP2500 was an ‘unknown’ to us,” Rogers adds, but we can see that it will be an excellent choice for many applications in our shop, even though we only have the one big lathe that can handle its potential. We’re trying it on our smaller machines, and it’s reducing many jobs by 50-60%.”

Although V&M relies upon a distributor that carries tools from many cutting tool suppliers, Rogers says he turns to Seco when he has time and production capacity to analyze the best options.

Rogers plans to have Seco come in and run other training sessions for his machinists.
“Tool companies have made it a snap for today’s workers, because they give you all the data you need when you buy the tool,’ he says. “Even so, we believe workers are not getting the shop floor education they need to optimize the cutting tool operations. We need partners like Seco to help us train our staff and achieve our optimum efficiencies.”

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