Doing What's Difficult

METALEX IS INSPIRED TO DO WHAT OTHERS DEEM TOO DIFFICULT (3-machine grinding cell produces what others could not)

Ford Motor in Batavia, OH requires a highly complex, micron-close tolerance transmission component (shaft) for their CVT 23 continually variable transmission shaft.  Little did they expect the supplier to be in their own backyard and already the vendor of choice for respected clients such as NASA, Northrop Grumman, the U.S. Department of Energy, Procter and Gamble, Pratt & Whitney, Boeing and other companies needing complex parts machined.  That supplier is Metalex.  Ford was looking for a supplier not only to produce the close tolerance, difficult to grind CVT shafts to spec but needed finish parts within 120 days ready to be assembled in their transmission. 

CINCINNATI, OH — Rudi Willems, Operations Manager, Grinding Division of Metalex Manufacturing, Inc. (Cincinnati, OH), reflects on the part that his team is grinding in a three-machine cell consisting of a Studer S31, a Studer S33 and a Jung C-740-D, all supplied and installed by United Grinding (Miamisburg, OH).  "If this were a job that anyone could do," he says, "then we wouldn't have taken it on". "We are a contract manufacturer of diverse applications, providing solutions for highly precise work, which sometimes involve challenging materials."
 
The pressures of time
As if the micron-tight tolerances and the super fine finishes weren't challenge enough, the time frame between being awarded the CVT shaft job and delivering product to Ford was imposing to say the least.
"The machines arrived in December of 2004," he says, "and we began shipping parts to Ford in February of 2005.  That’s pretty remarkable.  There were several weeks when we all worked pretty much around the clock."  "Keep in mind," says Willems, "the building housing the grinding cell and inspection room was an empty warehouse.  We didn’t have adequate power, air, water and other services running in there to support cellular grinding.  We had to make it a climate-controlled environment.  We had to acquire the machines, install the cell, do the training, acquire and install the inspection equipment……this was a very big effort.  We couldn't have done this without the complete cooperation and dedication of all partners: Ford, United Grinding and our self-directed, team-based workforce."  He notes further that there wasn't even time in the tight schedule to set-up the machines at United Grinding and run off parts.  "They brought the machines in here, set-up the cell and trained our team and we began running parts."

The cell
 "The shaft is produced in three operations in the United Grinding cell," Willems explains.  OP 130 is done on the Studer S31 universal cylindrical grinder.  The operation includes grinding on two large diameters, an undercut and a critical facing operation.  The two diameters are held to 10 microns and ground to an Rz 4 finish (one Rz equals approximately 0.21 Ra, although there’s not a direct conversion from the decimal finish Ra and the metric Rz).  The cone face has to have a finish between Rz 2 and Rz 4 with an acceptable angle on the face of 11 degrees.  The dimension from the back plate to the datum point on the cone face is 20 microns.  OP 140 is ground on the Studer S33 universal cylindrical grinder and consists of grinding four small diameters, a critical bearing diameter and a chamfer on the shaft end.  The four small diameters are held to 6 microns , the bearing diameter is 6 microns as well.  Finishes are again critical – Rz 4 on the small diameters and Rz 2.2 on the bearing diameter.
Following both OP 130 and 140, the shaft is placed in a Marposs fixture for a dynamic test to confirm tolerance and surface finish accuracy.  Now the shaft is ready for OP 150, the grinding of the ball tracks on the Jung C-740-D surface and profile grinder.  “This is a very critical operation,” Willems says, “even though the length of the ball track doesn’t look too demanding.  What we’re actually grinding here is a Gothic arc in the ball track.  There are really two radii with a kind of smooth flat at the bottom, and this has been designed so that the ball bearings run on the same face all the time without touching the bottom.  The profile of the ball track has to be 22 microns and this needs to be held over the entire length of the groove.  If you have as little as a 5 micron taper, you're already out of tolerance on the profile.  At this point, we're able to hold 5 microns consistently which means that the Jung is really doing its job.

Vendor Selection

Metalex and the customer, Ford Batavia, selected United Grinding as their vendor of choice to supply the grinders for the CVT-23 shaft project based on three major factors. First, United Grinding’s state-of-the-art facility in nearby Miamisburg includes test and R&D capabilities on site, which in any start-up effort is a tremendous plus. Second, their product lines include both Studer cylindrical grinders and Jung high-precision surface and profile grinders (among others), which are known to be "world class". And last, United Grinding’s expertise, knowledge base and know-how in the field of CNC grinding.

What Metalex and Ford did not know was how United Grinding would perform under fire. With finished parts needed by Ford in 120 days, turnaround time was critical. Therefore the cell was developed utilizing machines already in stock, which were then specifically tooled up for the CVT 23 shaft on the floor of Metalex' facility in Cincinnati. Working together Metalex, United Grinding and Ford were then able to produce parts that met the stringent specifications required.

"They brought the machines in here, set-up the cell, trained our team and began running parts. There were many issues and disconnects but United Grinding’s technical staff immediately took ownership and went into overdrive eliminating one issue at a time with the only goal being to ship the customer good parts on time", recalls Williams. 

Teams & Partners

Despite the belief many have of USA manufacturing being doomed; the contrary is this prime example of what can be accomplished when companies work as partners and people as a team.  There is no way Metalex and United Grinding would have been successful without the coaching by Ford's management team and the knowledge sharing and expertise supplied by Ford's technical support staff during the 24/7 start-up period.
Teamwork and a self-directed workforce are pillars of the manufacturing strategy at Metalex.  It is Metalex' culture to give everyone an opportunity to be the best they can be says rookie cell leader Artie Artrip following Metalex' total commitment towards our lean policy of continuous improvement and eliminating waste and no value effort wherever we find it.  In fact, many of the team members wear shirts that say Metalex on the front and "I've got a partner, I don't need a BOSS" on the back.

"Metalex would be a difficult place to work if you weren't dedicated to the idea of self-direction and teamwork," Willems says.  “This is because we're always working on the leading edge of high technology, and I don’t think you can walk on that edge without people who are willing to move by themselves, make decisions, take control and work together.  Our people know what they're doing and just get it done."

Rudi Willems says it best, "our suppliers and those we supply to are viewed as team members.  We simply don’t know how to work any other way; it's part of Metalex' culture with total customer satisfaction every time."