Schmidt Case History - Dexter Axel
Stamped and Riveted Tags Out, Traceability In.
Operating plants in 5 states, Dexter Axle Co. (Elkhart, IN) is a leading manufacturer of axles for trailers. Dexter makes axles and related components including spindles (axle ends), brakes, wheels and rims and suspensions. Dexter’s customers manufacture trailers used for recreational vehicles, boat hauling, livestock transport, as well as over the road and off highway designs.
As is the case with motor vehicles, key components are marked for traceability. For nearly four decades since its 1960 startup, Dexter Axle workers drilled and riveted a stamped identification plate to every axle they shipped. However, as company operations grew from a 20-man shop in Elkhart, Indiana, to nine plants employing 1,400, the shortcomings of tags and rivets became apparent to all.
The Ease of Integration with Schmidt Styliner®
After a thorough evaluation, they chose the Styliner® series of dot peen pin marking systems from Schmidt Marking Systems (Niles, IL). Starting with just one Styliner®, and now there are 16 installed in seven axle factories; one or another of these Styliner®s marks every axle as it comes off a production line. Key criteria in Dexter Axle’s evaluation were the ease of integration with fast-paced production systems, ease of use, quality of the mark, ease of fixturing, and ability to meet the plants’ production rates without raising costs.
“Durability and Schmidt’s sales force responsiveness were also factors,” said Lawrence Holz, manufacturing engineering manager on the headquarters engineering staff. “After we got into production, we found that a certain spring was breaking about twice a week and that stylus life was much shorter than expected. They handled it well and we have not had any outcries since.”
Dave Noonan, Schmidt sales engineer, elaborated: “We realized that Dexter used our markers more in one week than most customers did in a year, so we make the necessary modifications.”
Demanding Production Environment
Dexter Axle’s production environment is demanding. It manufactures about 1.3 million axle assemblies a year. It builds nothing to stock, hence the emphasis on fast-changeover LEAN manufacturing methods.
Every axle is custom ordered; there are no standard designs. “Diameters range from under two inches to five inches,” said Holz. Lengths vary and the Torflex™ designs have added square tubing to the mix.
Varying widely is the combination of “running gear” (spindles, hubs or drums, rims, wheels, brakes, and suspensions) that are welded or bolted to the basic axle. The average order quantity is only eight, Holz noted, and some plants turn out over 400 axles per assembly line-shift. That means production runs may be changed 50 times or more in each eight-hour shift.
Styliner® Marking Heads are Foolproof
All this is tracked in Dexter Axle shop orders and the shop-order number always goes on the axle. Also plainly marked are load and service limitations, which are tied to the warranty coverage. Getting information into the Styliner® about quantities and configurations is foolproof. It is scanned in from the shop order documentation and immediately displayed.
As soon as the parts are fixtured, the Styliner®’s door is closed. Marking begins automatically when the door closes. The Styliner® creates a series of overlapping dots with a pneumatically driven carbide stylus that acts as a “mini-jack hammer.” The stylus head automatically adjusts for axle length and diameter, the part is marked, and then the axle is ejected onto a conveyor.
Styliner®s for Traceability
“We moved all our production to the Styliner®s for traceability and quality assurance reasons,” Holz said. “The stamped aluminum identification plates occasionally came off after a few thousand miles of bumps, gravel and vibration. Once that happened, there was no way to order replacement parts or track warranty information,” he added. The GTS machines also led to labor savings by eliminating manual drilling, riveting and “human intervention” to make sure each axle got the correct tag.
Over all the installations have gone well in the plants even though the very first units required longer time to install than perhaps management would have liked. “That was pretty much due to a cost-saving decision to make the fixtures and tooling in-house rather than pay GTS to do it for us,” Holz said. “We worked with the industrial engineers to get the parts flow and needed a couple of iterations to get it right. Now the markers are installed quickly and easily. We will be buying more for additional production lines.”