Swiss upgrade yields up to 40% faster cycle times, improved yields.

More than a machine tool, a management tool

The pace of change in medical device design and manufacturing is very rapid and is fueling demand for machine tool capability that not only reduces cost per piece today, but can open doors to producing new types of parts in the future.

Oscor Inc., Palm Harbor, FL, already a successful medical device manufacturer, knows this very well and has taken strong steps to stay ahead of the curve.

The company designs, develops, manufactures and markets a variety of highly specialized permanent and temporary pacing lead systems. The company's pacing leads are used in connection with pacemakers, both implantable and temporary pacemakers systems that are used to treat cardiac bradyarrhythmias (an adult heart rate below 60 beats per minute) and other coronary disorders.

Not long ago, a new TRAUB 7-axis TNL18 turning machine was delivered with training and very attentive support from INDEX Corp, Noblesville, IN. In its first setup at Oscor, the TRAUB defeated an R&D setup for a high-nickel, chrome and molybdenum part by 3:1 in a less than 500-piece run. “And we see the possibility for even better results as the capabilities of the machine are fully utilized by a well-trained operator,” said Udo Wollmann, Oscor director of operations.

And as the company loads part programs for current production into the TRAUB, it is also finding that the convertible machine is able to reduce cycle times on those parts by up to  40% part for part compared to its  current equipment.

“So for us, the number one reason was machine capability. This magnitude of cycle time improvement proves that the TRAUB machine will be for us a very worthwhile investment,” said Mr. Osypka.

To date, Oscor is finding that the TRAUB allows the company to optimize every facet of production, minimize tool wear, and reduce cycle time. This is due in part to the training from INDEX TRAUB and also that the machine tool builder helped Oscor identify ways to make its parts more efficiently, reports Mr. Wollmann.  As Oscor works with the machine, it is also able to improve its yield of usable parts.

The TNL18 gave Oscor the ability not only to run its current parts faster than previously, but also allowed the company to pursue the production of parts they had been unable to produce on current machines, due to a greater number of axes and more tooling options.

“We need the extreme flexibility in order to be a leader in our industry and to quote parts we may not have had a chance to earlier. This also opens opportunities for us to discuss new possibilities with potential customers,” said Mr. Wollmann.

Compared to other Swiss turning machines that the company runs, the TNL18 has the capability to be used as a milling center, because of the range of tooling and axes it features. According to Mr. Wollmann, “milling data is the same on the TRAUB as on the company’s milling centers plus you have the option of orienting the part to the tool in many different ways, facilitating chip clearance, and reducing cycle time.”

The TRAUB also allowed the company to run a part from bar stock rather than milling blanks, saving a great deal of processing time on those parts. Oscor can also decide not to use the bar feeder when producing shorter runs and extreme tolerances-to .02 microns.

“With the TRAUB, you need to be a little bit broader minded than you might be with a typical Swiss machine because of the wider range of capabilities the TRAUB brings to the parts,” he continued. “This machine does operations I never thought of putting together--that’s what I like about it. I have a pretty good imagination, and I don’t see the end of what we can do.”

“By the same token it has to become part of your process planning to fully utilize the capabilities and improvements the TRAUB offers. You cannot process the same old way if you want better results.”

Paired with the TNL18 is the TRAUB Winflex programming and simulation software which allows the programmer/operator to simulate tool paths and optimize the programs prior to running parts.

INDEX provided extensive training for the operator on the machine and the WinFlex simulation programming. With its 2D- or 3D-simulation that can run backwards and forwards parallel to the program creation, WinFlexIPS is an easy-to-learn program creation option.

WinFlex permits the parallel programming and depiction of up to 4 subsystems with simultaneous simulation of the machining, as well as numerous functions for creating, checking and optimizing the machine process, including a wide range of functions and cycles
and clear presentation of all parts systems. Through user-oriented operating controls part data is input through WinCAD.

Said the machine operator, “WinFlex is very easy to use. Its tools allow me to do in minutes what would take me hours with paper and a calculator--and I have years of experience. We prefer offline programming so as not to interfere with our production. 3D simulation also allows us to avoid interference in the machining process.”

“We have done a few parts already where I have been able to cut the cycle time in half compared to what we run on the other machines due to the versatility of the TRAUB. I can do overlaps and crosses that typical machines cannot.”

“The only limitation to what you can accomplish on the TRAUB is in your mind,” the operator said, “because there is so much there: three tools in the cut at a time, sub-spindle work simultaneous with 4-spindle work (both spindles at the same time) means there is a lot going on in the machine at all times.”

The TRAUB machine is capable of multiple machining functions, including milling. And the rigidity of the machine’s construction is well-suited to machining micro-parts in the tough material Oscor uses, including titanium and special steel alloys. The TNL tool positioning is nearly unlimited, allowing Oscor programmers to put the tool points where required very rapidly.

TNL18 Convertability

Oscor also likes the convertability of the TNL from sliding to fixed headstock which saves production time and dramatically increases the versatility of the machine for the company and the many different parts it produces.

The TNL18 can be changed over in minutes to produce precision parts with or without a guide bush for long or short parts from bar up to 20mm diameter. The extremely long Z-travel distance of the headstock ensures the proper positioning of the main spindle, either for turning with a guide bush or without.

A swiveling sub-spindle is fitted to an X/Y/Z cross-slide, which at the same time carries the bottom tool turret. This slide, with large axis travel distances, provides plenty of space for three-axis reverse side machining, even for geometrically complex work pieces.

The tool capacity of the TNL18 can be increased to as many as 54 tool places through dual- and multi-holders of live and fixed tools, enabling extending productive time. The high-precision turret indexing permits a chip-to-chip time of only 0.3 s.  The solid back working attachment accommodates seven tool holders of which three can be driven.