Andretti Autosport CNC machinist Adam Erwin looks over the suspension dampers he just finished crafting for his team. Less than a day ago, the collection of dozens of tiny parts were just an engineer’s idea and a slab of metal, a dream to shave 0.1 seconds off a lap time.
That’s the life of an autosports machinist. Every day, 25 pairs of eyes scrutinize every race car component he machines – from the engineers and mechanics who design and install the parts to the drivers and sponsors who rely on them for victory. Each one of them expects Erwin’s parts to be precise, resilient, and aesthetically perfect before they can be used in an Andretti Autosport Indy car.
Like its cars, Andretti Autosport works fast. Based in Indianapolis and led by racing legend Michael Andretti, the team operates under stringent time constraints where every component must be perfect and produced as quickly as possible. And while many parts must remain stock to ensure an even playing field for all drivers, teams can make some vehicle modifications. This is where Erwin and the Andretti team’s other in-house CNC machinists come into play.
Suspension components and dampers (shock absorbers) are two major car features open to modification. Racing teams will often develop new, proprietary parts to continually improve car performance and shave valuable seconds off lap times.
Choosing the right tools
As with any machine shop, the rapid development, manufacture, and testing of new part concepts puts increased pressure on Andretti’s machinists. They must continuously improve upon levels of precision and productivity while also maintaining component aesthetics.
To achieve these goals and stay well ahead of the competition, the Andretti team relies on the speed, performance, and accuracy of advanced cutting tool technology from Seco Tools LLC.
Seco has been a technical partner of Andretti Autosport since 2010 and not only provides the team with the industry’s latest milling and turning tools, but also expert application support.
Andretti machinists work closely with Seco, reviewing race car component designs to select the types of tooling needed for specific tasks. Seco applications experts then recommend certain types of tools based on part material and suggest the proper speeds and feeds for that tooling.
Every racing season, the Andretti Autosport team builds Indy cars for each of its four drivers: Ryan Hunter-Reay, Marco Andretti, Carlos Munoz, and James Hinchcliffe. Every car has a backup – in addition to another one specifically for the Indianapolis Motor Speedway, totaling nine cars for the season.
“Sometimes we get in a bind,” Erwin explains. “The team will discover mechanical issues while at a track for a race, and they will need a part reworked or otherwise altered. In these instances, same-day turnaround time is mandatory. We get the print in the morning and must have the part finished that afternoon.”
On top of its general season production, Andretti constantly tests and refines its cars, incorporating new developments in the vehicle design. For this, the team depends heavily on its partners to stay up to speed on the latest technology, including tooling, software, testing methods, and materials.
Finding the right partner
Trusted partnerships allow Andretti Autosport team members to focus on part creation and testing while knowing they’re using the most advanced tools, materials, and methods possible to maintain a competitive advantage without wasting time or additional resources on research.
“Without partnerships, maintaining our competitiveness would involve a lot more time and effort and, in many instances, trial and error,” Erwin says. “Fortunately for us, our partnerships help us manage and reduce the two biggest costs in racing – motors and the R&D process.”
In typical season production, each Andretti team machinist cranks out between 12 to 15 different jobs per week, doing all his own programming, fixturing design, and setups. Machined parts encompass different complex geometries and profiles, in addition to stringent clearance features, surface finishes and tolerances from ±0.0100" to as tight as ±0.0003".
Part sizes can range from 0.07" (2mm) in diameter up to 8.00" (203mm), with the majority of workpiece materials being aircraft-quality 7075 aluminum, 6061 aluminum, and titanium. Overall, 70% of Andretti’s parts require turning operations, 30% require milling, and then there are those that require both machining operations.
As a result of its partnership with Seco, Andretti has recently incorporated turning and threading inserts, high-feed milling cutters, inserted thread mills, and boring heads.
The team uses Seco’s high-feed milling cutter with Duratomic inserts to machine suspension components and parts for a shaker testing rig, along with Seco Jabro solid-carbide end mills to cut carbon-fiber brake pads.
The high-feed milling cutter allows the team to handle a wide variety of applications, including contouring, slotting, and plunging with a cutting diameter of 2.00" (51mm).
Each brake system requires titanium parts that are difficult to machine. With Seco’s TP3500 insert grade, the machinists gain increased control and accuracy for these tough cuts. Seco tooling also is used to drill any necessary holes in these tough parts.
Machining suspension parts
The advanced Seco tooling has shortened machining cycle times and improved surface finishes for some of the most critical parts – suspension dampers.
Dampers control how a car rolls through a racetrack’s corners and absorbs its bumps. Cars have four dampers – two in the front and two in the rear – that are matched to the unique conditions of each race course.
Dozens of tiny parts make up one damper. While Andretti essentially uses some off-the-shelf parts, its machinists manufacture the lion’s share of damper components.
After Erwin and his team manufacture the parts, they test them in a shaker rig, putting the part through cycles that shock absorbers must endure on the racetrack.
For instance, the team manufactures studs from ET150 (a chrome molybdenum steel) that are tested for strength and weight. They entail special thread profiles with root radii that give them strength to withstand punishing racing conditions. Andretti machinists use Seco thread turning inserts to generate those root radii.
As Andretti Autosport continues to develop new and improved car components, the team often runs into specific machining challenges where demands stretch beyond the capabilities of standard tooling. In these situations, Seco provides custom tooling support.
Moving work in-house
Prior to its partnership with Seco, Andretti Autosport would rely on a variety of vendors to fulfill tooling needs. But Erwin says the tools were basic and limited in application capability.
“Quite often, we had to grind clearances by hand on tools and make other modifications to tailor them to our specific tasks,” he explains. “This extra tweaking was time consuming and it bogged down our part machining operations.”
With Seco, Andretti’s tooling technology level has advanced dramatically. Erwin says team members now simply access the Seco catalog and acquire any necessary tooling for the job at hand; no longer wasting valuable manufacturing time grinding or otherwise altering tools.
“At the speedway, we’re turning laps at more than 220mph in some of the most advanced racing vehicles,” Erwin says. “And to build those cars, we rely on tooling as equally advanced from Seco.”