IT'S ALL ABOUT AN EDGE. PLAIN AND SIMPLE.
Penske Racing South can machine a complete crankshaft from a solid billet on a Mazak Integrex turn/mill machine.
The Dale Earnhardt Inc. racing team uses a VMC-1250C, supplied by Cincinnati Machine, to add water lines and remove excess metal from cylinder heads.
Hendrick Motorsports machines more parts in-house, such as these, using its VF-4 VMC and HL-4 lathe from Haas.
Using EDMs from its Agie sponsorship, Joe Gibbs Racing experiments with light, exotic materials that are too hard for conventional machining methods.
Joe Gibbs Racing team produces car components — once made from welded pieces — out of solid steel and aluminum billets on its Daewoo DMV-500 VMC.
Nascar teams are getting an edge over the competition by keeping more parts manufacturing in-house on equipment supplied through machine tool company sponsors. These "partnerships" give teams process control for consistent part making and fast turnaround times for new design testing. And when problems arise, teams have the OEMs, themselves, for expert advice.
According to Donald Miller, president of Penske Racing South, home to the #2 Ford Taurus driven by Rusty Wallace, on any given Sunday up to 25 cars have a strong chance of winning a Nascar race. The margins are so small, "you can throw a blanket over the top 10 cars as they come across the finish line after a 500-mile race."
Out of 60 cars that qualify for a race, there is maybe a two-tenths-of-a-second difference between the first and last cars and hundredths of a second between the top 20 cars. This is why Nascar teams strive for even the smallest technological edge, and Penske's comes from its Mazak sponsorship.
The team currently has two VMCs built by the Florence, Ky., manufacturer, an MTV 515-40N and a SQT 200MY. These machines make small, intricate parts for transmissions, differentials, suspensions, and engines. Because it manufactures more in-house using the latest machine tool technology, Penske controls part quality better and speeds its over-all car production.
For example, the team no longer grinds valves and valve seats. It cuts them. This reduces the process from 9 hr to 20 min. And on engine blocks, Penske does various types of machining after getting the castings from Ford.
On a 355-in. 3 engine block, for example, team machinists cut cylinder walls then bore/ream lifter bushings. If they used a stock, machined Ford block, says Miller, it would be difficult to trace and eliminate problems. This is one of the best advantages of machining in-house, he adds. "If you have to buy it from somebody, there are no secrets and no edge."
With today's machine tool technology, teams can push the envelope because part manufacturing no longer involves trial-and-error. What once took 3 months, may now take 3 hr. "The gains are astronomical," says Miller, and he cites working with Mazak on crankshaft manufacturing as the perfect example.
Mazak's recently developed turn/mill machines, the Integrex series, cut a complete crankshaft from a sold billet of steel in 8 hr. With this equipment, Penske can quickly modify crank designs for optimum speed by simply reprogramming the machine.
An Integrex features a rigid turning spindle and C axis for CNC servo control of the main spindle's rotation. With the machine's Y axis, Penske's machinists can mill, drill, and tap off-the-centerline. In addition, a 10-hp B-axis machining spindle (live spindle) rotates a total of 225° for working angled features in increments of 0.001°. All these motions are necessary for the complete machining of a rough crankshaft.
Before the Integrex, Penske ordered three or four cranks at a time, each with a particular stroke size, pin diameter, weight, and so forth. And because there are only so many crankshaft makers, the team would wait up 8 weeks for the order. In the meantime, other racers who had new crankshafts were winning, says Miller.
Besides making crankshafts from solid billets, engine-cylinder-head production probably best illustrates how Nascar teams benefit from today's machine tool technology. With CNC machines, more teams are doing heads in-house — automating the process and drastically reducing cycle times. Two such teams are Dale Earnhardt Inc. (DEI) in Mooresville, N.C., and Hendrick Motorsports, Harrisburg, N.C.
At DEI's new racing center, there is a part of the shop referred to as the "Cincinnati room," called that because it houses three machines from sponsor Cincinnati Machine, Cincinnati. In the room is a 5-axis Arrow VMC-1250-C, a 3-axis Arrow VMC, and a Hawk TC-250 turning center, all of which produce parts for team cars #8, driven by Dale Earnhardt Jr., and #1, driven by Steve Park. But arguably the most important components coming out of the Cincinnati room are cylinder heads.
DEI uses its CNC equipment to machine in water lines, open holes, remove metal for weight reduction, and prepare heads for valve seating. On a manual machine, all these operations take about six hours, with most of that time being spent on the job's six setups. According to DEI's CNC Programmer/Operator Steve Long, machining operations take as little as 1 hr on the 1250-C. And with its fully integrated rotary table, the machine eliminates multiple, progressive setups and improves accuracies between related, machined surfaces.
The 1250-C has digital glass scales on its X and Y axes for +0.00011-in. positioning accuracies and 0.00004-in. repeatability, which is crucial in cylinder-head production, especially when it comes to porting.
To improve engine performance, racing teams polish a head's intake ports (porting) so the fuel/air mixture flows efficiently and unrestricted to the cylinder. Typically, a skilled technician with years of experience painstakingly sculpts and polishes ports manually. The process can take between 80 and 100 hr, with no guarantee the heads are usable. To make matters worse, once a set of heads does work well, it is difficult to not only duplicate dimensions from port to port, but even more so from head to head. But thanks to CNC machining equipment, Nascar teams can now reproduce these one-time, works-of-art.
Once a particular head design works, its shape is digitized using a CMM. This digitization then easily transforms, via CAD/CAM software, into a cutting-path program. Finally, DEI's 5-axis 1250-C machines the heads.
Hendrick Motorsports, home to #24 Jeff Gordon, #5 Terry Labonte, and #25 Jerry Nadeau, had already discovered the benefits of CNC machine tool technology for engine heads by the time sponsor Haas Automation Inc., Oxnard, Calif., came on board.
The team was machining on a universal machining center with both horizontal and vertical spindles and 5-axis capability. It successfully automated cylinder head manufacturing, so well, in fact, that the team brought even more farmed-out part production in-house. Hendricks needed to expand its horizontal and vertical CNC machining, and the sponsor-ship from Haas did just that by providing two HS-1R5AX HMCs, two HL-4 lathes, and a VF-4 VMC.
Hendrick ports heads on its HS-1R5AX, which includes a built-in, fourth-axis rotary unit and added hydraulic tailstock on an optional 19 40-in. extended table. These three components comprise a fifth axis. Special flanges, designed by Jim Wall, engineering group manager at Hendrick, secure heads for machining. The machine runs around the clock, says Hall, and reduces complete engine-head cycle times to 6 hr.
Cycle times for heads are dependent on how fine of a machining increment is used for a good finish. According to Wall, 0.040 in. is the standard increment, but he's gone as low as 0.020-in. "I intentionally made the program big," says Wall, "It was 11 mbyte and no problem for the Haas machine's expanded memory. The HS-1R5AXT cuts efficiently because of its inverse-time motion, which keeps a consistent chip load on the tool."
On the HL-4 lathes, Hendrick machinists make front dampener washers along with pulley and suspension parts. They also turn wrist pins for pistons — a job that they couldn't do without the Haas machine. The lathes feature a 14.5 34-in. turning capacity and programmable hydraulic tailstock. According to Randy Dorton, director of the engine department at Hendrick, the lathes were the first CNC turning equipment for the shop.
With 50 2025-in. X, Y, and Z-axis travels, Hendrick's VF-4 VMC handles all the engine shop's plate work, engine brackets, braces, and other accessories. It also cranks out small surfacing jobs, drills, taps, and profiles.
Because of the VF-4, Hendrick will bring even more parts in-house, and not just engine components. According to Wall, the shop plans to use the VMC for five-axis work, making chassis parts.
But what did Nascar teams do before having these laid-out facilities and the ability to make critical parts in-house? Well, as Mark Bringle, CNC coordinator at Joe Gibbs Racing, puts it, "we weren't consistently winning races."
Sponsorships from machine tool builders Daewoo Heavy Industries, West Caldwell, N.J., and Agie Ltd of Davidson, N.C., play an important part in keeping Joe Gibbs drivers, #18 Bobby Labonte, and #20 Tony Stewart, ahead of the pack. But it's more than just free machine tools. "The whole company comes with the partnership," says Bringle, "and both team and sponsors work together to develop the best manufacturing processes."
From Daewoo, the Gibbs facility in Huntersville, N.C., has three DMV-500 VMCs, an Ace-H-500 HMC, and both a Puma 200C and Puma 300M turning center. With these machines, Gibbs produces an innovative engine motor mount that shears off and away in a wreck to avoid damaging the car's valuable engine block.
The team also machines parts — once comprised of welded components — out of single, solid billets of steel and aluminum. As in aerospace manufacturing, the goal is to create parts that are lighter, but just as strong. One such billet part is an alternator cover. The Daewoos, with their extensive tooling, complete a cover in 2 hr and 15 min.
Gibbs' DMV-500s feature 30-station, double-arm, random-access automatic tool changers that have tools ready and waiting at load time, even for the shop's short-cycle parts. Tool changes take 1.5 sec, and chip-to-chip times are 4.5 sec. The H500's toolchanger houses up to 60 tools and handles CAT 50 shank tools.
For every race, each car needs three motors, which, along with other components, have been tailored to a particular race track. There are over 34 races in the season, and Gibbs has two drivers. That adds up to a lot of production for Gibbs, it's six motors per week. To stay cost effective and keep up, the team runs many multiple-part setups. Operators run parts with long cycle times overnight and those with short cycle times during the day.
According to Bringle, all the car's parts are light and made to just finish a race, not last for 150,000 miles. As a result, teams push motors and other components to the limit, design-wise. While Gibbs will machine car components to reduce weight, it also experiments using new, light, exotic materials that are too hard to machine. For these parts, the shop benefits from EDM technology and its relationship with Agie.
On the team's Agiecut Challenge 2 wire EDM, operators separate parts into halves, losing a minimum of material. And on an Agie Mondo Star 50 sinker, they burn shapes in parts that were also once welded constructions. The machine easily handles these hard-to-machine shapes, so much so, says Bringle, that they have.