Quick-Change Spline Rolling Racks Offer Numerous Benefits

U.S. Gear Tools Inc. of Swannanoa, NC has developed the R/C Rack System, a quick-change tooling alternative for spline rolling machines. The system saves time, simplifies logistics and has the potential to significantly increase tool life, says Mike Callesen, director of spline rolling products.

The R/C Rack System consists of two pieces: a durable carriage that is installed into a standard spline rolling machine, and a replaceable, one-use rack insert. The two pieces align with a simple cam-lock system that requires only a standard hex-wrench to turn each of five actuators.

Installing the carriage is similar to installing a standard spline rolling rack, Callesen says, except that the R/C carriage is just over half the weight of a standard rack, making it much easier to manage. But the real advantage of the R/C system, he says, is the quick changeover.

A typical tool change with old-style tooling was measured in hours, Callesen says, whereas the R/C system requires only about eight minutes. “Once you’ve got the carriage set in the machine and you’ve run good parts, changing the insert is a piece of cake.”

Another important benefit of the quick-change system is greatly simplified logistics, Callesen says. When a standard rack tool’s performance diminishes, it can be restored by regrinding as many as five times. But this means the machine has to be stopped and the tool removed, packaged up and shipped back to the tooling supplier—a time-consuming and expensive process. Also, it requires the spline manufacturer to keep at least three spares of each type on hand and manage the inventory, knowing which racks are in machines, which are in inventory and which are out for regrinding. In an automotive scale operation – possibly with hundreds of rack tools – tool inventory management is no small task.

The R/C System’s inserts, however, are designed to be discarded after they reach the end of their useful life. The carriage stays in the machine and a new insert is installed in just minutes. Although Callesen still recommends that manufacturers order their spline rolling racks in sets of three, they only have to keep track of what’s installed in a machine or on the shelf. They no longer have to worry about what’s being resharpened or in transit.

Also, the R/C rack inserts weigh significantly less than a full spline rolling rack, so they can generally be shipped via standard FedEx or UPS. Also overseas customers don’t have to worry about how they’ll get their used racks resharpened and the difficulties of shipping pieces back and forth across borders. New inserts can easily be shipped overseas.

Although the R/C Rack System was first introduced at IMTS 2012, U.S. Gear Tools has spent the past two years refining the system. They have worked very closely in conjunction with a major Tier One automotive supplier and produced more than one million parts using the tools, Callesen says. This testing process has allowed U.S. Gear Tools to make sure the tool performed as expected and that its installation and use were as user-friendly as possible.

Most importantly, however, the testing and development also revealed that the new design seems to provide a significant boost in tool life over conventional tools. In fact, for this automotive application, tool life was approximately double what the manufacturer previously experienced using standard spline rolling racks.

Of course, Callesen is quick to point out that not every application should expect double the tool life. However, because of the volume of parts run, the company is confident that most applications will see appreciable tool life benefits. “The design of the tool enhances the tool life,” Callesen says, explaining that instead of one rigid body, as in a traditional spline rolling rack, the two-piece design of the R/C system allows the tool the tiniest bit of flexibility. This flexibility is the secret to reduced tool wear, but it has absolutely no effect on the produced parts’ quality, Callesen says.

Officially, the tools went on sale in the beginning of 2014. Racks are currently available only in 24" lengths, which is the predominant size required worldwide for automotive splines. According to Callesen, the company has completed its design for 13" “thread rack” tools, and these should be available by summer, with 48" racks by the end of 2014 and 36" racks in 2015. All tools are designed to fit in a standard spline rolling machine with no modifications required.

Although the R/C Rack System tools cost more than standard rack tools, the value they offer is well worth the difference, Callesen says. When compared with traditional tools, which can be resharpened and re-used several times, the cost of the R/C tools is about 30% higher. However, this considers the direct tooling costs only, Callesen says, and ignores the indirect costs of machine downtime, tool inventory management and shipping tooling back and forth for regrinding. Considering all of that, the total cost of ownership for the R/C Rack System can be significantly less than for standard tooling. And when you add in the promise of significantly increased tool life, the value of the R/C system becomes much more readily apparent.

The tools have been well received so far, Callesen says. Many customers are enthusiastic about the concept and are interested in learning more. U.S. Gear Tools is encouraging any spline manufacturers to give the new tooling a test on at least one of their lines. The company is confident that the results will prove themselves.

For more information:

U.S. Gear Tools, Inc.