Modern Machine Shop

JAN 2018

Modern Machine Shop is focused on all aspects of metalworking technology - Providing the new product technologies; process solutions; supplier listings; business management; networking; and event information that companies need to be competitive.

Issue link: https://mms.epubxp.com/i/919997

Contents of this Issue

Navigation

Page 74 of 163

second machine, with identical capability to the first, and he says there's been no lack of opportu- nity to leverage the new capability. "We've gotten the opportunity to do projects that we wouldn't have been able to attempt in the beginning, and we've been able to turn around some prototype orders in a couple of days." Thanks to the supplier's applications expertise, getting the first job into production took only a few weeks after the decision was made to move forward, Mr. Hornak says. These small, tubular medical components were fully machined by the time they arrived at the facility for laser welding and passivating operations, and quality issues and production delays alike filtered down from the upstream supplier. Upon seeing the LaserSwiss in action at a medical industry trade show, manage- ment saw an opportunity to not only address these issues, but also to provide an important customer with significant additional cost savings by per- forming all the work in one location. Done in One This first part was once processed at two different suppliers before reaching Northeast Laser, Mr. Hornak says. The shop that performed the bulk of the upstream machining had outsourced a cen- terless grinding operation used to finish a turned bearing journal on one end of the tube. Thanks to the repeatable precision of the Swiss-type lathe—a machine type defined largely by a slid- ing headstock and a main spindle guide bushing that supports the workpiece close to the cutting action—this journal can now be turned instead. A snap ring groove around the OD can also be machined in the same, fluid sequence with the finish-turning operation. Meanwhile, the subspin- dle and slots for 32 driven tools, spread across two gang tool posts and both front- and back-working stations, offer flexibility to perform various other machining operations on complex parts like this without removing them from the machine. The laser, of course, is best for the smallest, tightest features, such as two 0.090-inch slots on opposite sides of the OD that were previously cut via wire EDM. Like laser, EDM provides a partic- ularly narrow "tool" for precision in tight corners and small features. The laser, however, is faster, Mr. Hornak says, and it requires no wire or other consumables (this is also an advantage over mill- ing, turning and drilling). Having this capability on the same platform as mechanical tools also ensures laser-cut features can be precisely and consis- tently located relative to machined features. In this case, Mr. Hornak says applying the slots via EDM would mean additional time and additional handling to ensure proper positioning relative to the bearing journal and snap groove. Part cut-off is another example. Previously, this operation was performed via electrochemical cutting, a process designed for accurate, burr- free edges. However, the laser provides the same advantages, with the right settings for parameters like frequency, power, gas pressure and the liberal application of f lood coolant through the inner diameter of the tube stock helping to keep the interior free of splatter. Meanwhile, chamfering and finish-milling operations on the tube edges can be performed in the same, seamless sequence as cut-off. (The reason for the milling operation is purely cosmetic, Mr. Hornak says, pointing out that laser cutting often leaves an oxide layer that looks different than a machined finish.) Northeast Laser can produce about 2,000 of these parts every week, with the lathe's automatic bar feeder facilitating lengthy, high-volume runs with little human intervention. In 2015, about a year after moving this job into production, the shop was presented with a second opportunity, this time to machine an entire family of tubular surgical parts in various sizes and configurations. This new job prompted the purchase of the second machine. The shop has completed a number of prototype orders for various customers since then, and it is actively seeking additional new work for the two machines. Welding and Beyond Northeast Laser isn't the only medical manufac- turer to use laser-equipped Swiss-types as set- up-consolidating alternatives to processes like EDM. Mr. Noake adds that potential applications extend well beyond medical. Whereas Northeast Notably, cutting isn't the only laser process available on the LaserSwiss line. Consolidating Laser and Traditional Machining Modern Machine Shop 73

Articles in this issue

Archives of this issue

view archives of Modern Machine Shop - JAN 2018