Amarillo Gear upgrades to the latest in HMC, VMC and Turning Center technologies —to achieve quality gains, WIP reductions and cut processing times in half

Company Profile: Amarillo Gear

Location: Amarillo, TX
Established: 1918
Products: Right-angle drives for agriculture, power processing and other industries
Market Area: Worldwide
Number of Employees: 139
Facility Size: 130,000 square feet
President: Glen McCain
Cincinnati Sales Agent: Hillary Machinery

AMARILLO, TX — Productivity gains in three classes of machining—horizontal, vertical and turning—mesh like interlocking gears at the Amarillo Gear headquarters here, where processing times for some parts have been cut in half. To meet the demands of a steady 15% annual gain in market share without compromising its reputation for prompt delivery and quality, Amarillo Gear had to accelerate production of its right-angle drives for irrigation pumps, oil pumps and cooling towers. The solution: Upgrade to the latest HMC, VMC and turning center technologies.

Since 1995, Amarillo has added four new Cincinnati machines:
* Two Falcon  Turning Centers —including the first production Falcon in the U.S. —cut cycle time by 20-25% on existing shaft parts, while holding 0.0005" (13 microns) total tolerance on the diameter on a new line of stem pinions.
* A Maxim HMC-630 Horizontal CNC Machining Center reduced total processing time for cast iron drive housings by 50%.
* An Arrow VMC-500 Vertical CNC Machining Center not only eliminated 50% of the processing time for oil seal plates and other ancillary components, but also lowered the work-in-process (WIP) costs associated with queuing these parts at manual machines.

'Superb' Support for 50+ Years

No newcomer to Cincinnati technology, Amarillo Gear has been a customer of "the Mill" for over 50 years. Production foreman John Cunningham says he sees the reason for continuing to return to Cincinnati every time he looks around the shop.

"Cincinnati is superb at supporting these machines," he says. Among the Cincinnati machine tools which are still producing for Amarillo—and still supported with stock items from Cincinnati's Service Parts Division—are a VerciPower Model 480 from the early 1960s, a No. 2 mill from 1958, and a 1941 Model ER grinder. "And Cincinnati shows no signs to reduce their commitment to stand by the new machines. If ever there’s a problem, we know they’ll have someone on-site to help us quickly."

Prior to the Falcon, Maxim and Arrow machines, Amarillo’s most recent Cincinnati purchase was a 4-axis Cincinnati T-40 horizontal machining center, which the plant continues to use to manufacture its very largest cast iron housings—parts ranging up to 50 x 25 x 20" (1.27 x 0.63 x 0.62 m). With its 39.3" (1000 mm) square pallets and 60 x 60 x 48" (1525 x 1525 x 1220 mm) X-Y-Z travels, the T-40 lets Amarillo perform all milling, drilling, boring and tapping in one setup—saving about 11 hours of processing time per part over previous methods.

Maxim: B-Axis Index, A-Class Rigidity

Amarillo’s 33.5 hp (25 kW), 7000 rpm Maxim HMC-630 has taken over production of 10 smaller housing models—ranging from 200 to 500 lb (91 to 230 kg), and occupying up to about 50% of the Maxim’s 40.4 x 31.5 x 31.5" (1025 x 800 x 800 mm) X-Y-Z work volume.

Equipped with B-axis indexing, the Maxim lets Amarillo bore top and bottom holes 180° apart in some housings, as well as a horizontal hole between them. Another housing features a horizontal hole 14.75" (375 mm) in diameter, which Amarillo machines by helical interpolating and milling.

"Maxim’s rigidity is fantastic," Cunningham says. Amarillo takes advantage of this to hold 0.0005" (13 microns) total tolerance on the diameter for bores taking press-in bearings, and 0.0003" (7.6 microns) on those taking bearings that slip-fit.

"The rigidity also lets us reach rough milling rates unlike anything we’ve achieved for these parts before," he says. Typical of these is 75 ipm (1.9 m/min) at 1000 sfpm (305 m/min) and 0.150" (3.81 mm) depth-of-cut, for an 8-tooth, 6" (152 mm) diameter ceramic shell mill.

Cunningham says streamlined setup is a key reason why the Maxim reduced processing time by 50% over the previous process. Each of the holes used to require its own setup—on a lathe for the top and bottom holes, and on a jig mill for the horizontal hole. Now, one setup lets the Maxim reach all of the holes in the same cycle.

Faster rapid traverse also contributes to the productivity gain, he says. The Maxim’s top feedrate is over six times what the jig mill could achieve, reducing non-productive time.

Shaft Cycle Times Down 25% on Falcons

Higher rapid traverse also accounts for nearly all of the average 20-25% cycle time reduction Amarillo has won from its 40 hp (30 kW) Falcon TC-300 and TC-400 turning centers. On the larger Falcon TC-400—with 19.2" (490 mm) part diameter capacity as opposed to 18.8" (480 mm) on the 300—Amarillo has transferred the machining programs used on an earlier Cincinnati Model MO turning center, with no change except to step up the rapid traverse rates to the 600 ipm (15 m/min) that both Falcons can achieve.

"The Falcon TC-400 takes the same cuts, at the same surface footage and feedrate, that the MO machine did," Cunningham says. "That’s impressive, when you consider that the MO is a 60-hp (44.7 kW) machine." Amarillo’s Falcon 400 is also the first production Falcon in the U.S.

Quality gains the Falcons have achieved include not only the 0.0005" (13 microns) total tolerance the shop is now able to hold on new stem pinion parts, says Cunningham, but also a consistent, noticeable improvement in surface finish for all of the parts the Falcons now machine.

"I chalk this up to the Falcon headstock design, which eliminates the geartrain. While we haven’t quantified the improvement, I’m certain our surfaces are a least 10 RMS better than what we’re used to seeing."

The two Falcons process more than 400 shaft part numbers, ranging from 1.5 to 4.5" (38.1 x 114 mm) in diameter, reaching up to 35" (889 mm) long. Both Falcon models come in two bed lengths, and Amarillo chose both—opting for 34.44" (875 mm) of workpiece length capacity for the 300 machine, and 54.13" (1375 mm) for the 400.

Intuitive A2100 CNC: Novices Productive in 2 Weeks

The Falcons share the same PC-based Acramatic 2100 (A2100) CNC that Amarillo’s new Arrow VMC-500 also uses. The CNC employs the Windows NT operating system, and features touch-screen operation, simplified shop floor programming, and a full-function hand-held remote pendant control.

"It’s very similar to the Acramatic 850 CNC our operators are used to, but with enhancements that make it much more intuitive, and easier to learn," says Cunningham. "I’ve introduced operators to the A2100 who had no CNC exposure, and they were running independently in two weeks—a fast learning curve."

On the Arrow, the A2100 also includes a mill package that allows Amarillo to save the coordinates of individual setups as separate files. Amarillo uses this feature in conjunction with tooling plates with dedicated fixtures, which are moved in and out of the machine as needed using a Jergens Ball-Lock system.

"The coordinates of each setup never change—so with the A2100, we only have to type them in once. We store each setup under a plain-English file name, then load that file when we’re ready to run the job. Changeover couldn’t be easier."

VMC Cracks the WIP

Amarillo’s 10 hp (7.5 kW), 6000 rpm Arrow shares an operator with an older Cincinnati Talon CNC Turning Center. Together, the two form a flexible workcell for machining about 250 different ancillary drive components, particularly oil seal plates. Each of these parts now goes into the two-machine workcell as a rough casting, and emerges ready for assembly—a far more productive system than the multi-machine process that preceded it, notes Cunningham.

"The Arrow alone has cut machining time by 50%, just by automating drilling and tapping operations that used to be largely manual." However, that tells only part of the story, he says—because the workcell’s work-in-process savings may well be more significant.

"Oil seal plates used to queue at a lathe, then a multi-spindle drill press, then a bench press—so each part spent about a week moving through the shop," Cunningham says. "But now, the Arrow/Talon work cell lets us complete a 100-piece batch in six hours—and that processing time is the only WIP we see."