Manufacturing Medical Equipment Requires Close Tolerance Machining |
|
|
Paul Prikos, vice president, X-L Engineering, stated that, "When the backbone of your operation is in the medical field, you have to be able to perform perfectly, repeatably. You have to hit tolerances right on the nose and surface finishes that would make some companies shiver. "It is all about cosmetics with medical instruments and equipment," he said. "The look and feel of the part is important. We do work in aerospace, defense, electrical, hydraulics and pneumatics, and these industries want good-looking parts, too. But the medical field is something else entirely different. They want an appearance that compares - or exceeds comparison - with finest automotive detail, for example."
About X-L "The industries we serve are primarily medical," said Paul Prikos, "although we do some aerospace work. The materials we process are steel, stainless, heat-treated steel. Actually there isn't a material that jumps out at me that we wouldn't tackle. All of this work is very tight tolerance machining with extremely fine finishes. "Our growth plans right now are for about 10 percent a year. Our annual revenues are just under $10 million. So, as you can see, we're relying on continued growth in the medical industry. And from what we can tell, it's there. Some amazing things are being done in the medical field."
Medical Examples Another medical job X-L produces runs on the Hardinge Quest GT275SP. These are drives and shafts for power tools in medical applications and, again, housings. "We're using this machine as part of a cellular setup. It's the second lathe in a lathe/lathe/mill cell," said Prikos. "What we particularly like about the GT is the unique gang-type tooling plate that holds all the tools. We can remove the entire plate, save the job with all the tool settings unmoved, put in a different pre-set tooling plate for the next job, touch off the new plate, and we are up and running our next job. As far as set-up time reduction goes, when you change the tooling in and out that fast, it dramatically reduces your set-up time." Prikos notes that these parts are all stainless steel, while some are heat-treated stainless, which is even tougher on the machine: "Working with these materials requires a very rigid, reliable and precise machine, and that's what we have in the Hardinge GTs; it's why we ordered two in the last year."
Cycle times
A Brief Look at
the Machines The Y-axis permits thread-milling and complex off-center milling and drilling operations on the main or sub-spindle. C-axis on both main spindle and sub-spindle provides positioning in increments of 0.001¡. Three dimensional contouring, complex round and prismatic machining, square shoulder and lettering are accomplished by synchronizing the spindle with the X- and Z-axes. Since Quest lathes do not require a spindle adapter for using collets, a larger machine area is available with bar length capacity of 24" on the 8/51SP. Programmable resolution/tool offset capability: 0.000010". Spindle configuration: A2-6.20C, with a through hole of 2.378" and chuck size of 8". Nominal work size with collet: 2.00" x 24.00" (OD x L). Travels: X-axis, 7.45" and Z-axis with collet, 24.00". Traverse rates: X-axis: 1100 IPM and Z-axis, 1500 IPM. Roundness and surface finish on the 8/51SP are 0.000020" on part roundness, and an 8 micro-inch part finish (dependent on speeds, feeds, tooling, machine maintenance, coolant, material, ambient temperature (68 ± 3¡F) and the type of machine installation). The Hardinge Quest GT27SP Gang Tooling lathe achieves surface finishes of 8 micro-inches and exacting part roundness of 0.000015". Plus, a continuous machining accuracy of 0.0002" gives the GT27SP machining consistency. Accuracy certification is included. 6000 RPM, 3-spindle live tooling is available. Key features: 5-HP spindle drive motor that achieves 3.5 sec. spindle acceleration from zero to 8,000 RPM and 3.5 sec. deceleration from 8,000 RPM to zero. Precision collet ready spindle with 1.0625" bar capacity allows quick spindle tooling changeover combined with the interchangeable tooling top plate reducing setup and non-cut time. Pre-tooled top plates can be removed and interchanged within 0.0002" in under a minute. The top plate accommodates up to 12 tools for small diameters, and tools can be added or removed from any location without disturbing any other tools. The optional tool-touch probe provides offset calibration, while low-friction/zero-striction linear guideways deliver improved accuracy and part finishes. Rapid traverse rates are 708 IPM (X-axis) and 945 IPM (Z-axis). Absolute encoders and preset servo drive positioning eliminate the homing sequence for X- and Z-axis. The 1,800 lb. HARCRETE polymer composite base provides super stability, machine damping and extended tool life.
A Great Fit Another way to look at the 8/51SP is to ask how many axes the machine has. Prikos said, "When you're talking about axes, you're usually talking about milling. With the 8/51SP and all it's various functions, one of which is milling, how many axis do we have? I'm not really sure. With the live tooling, the machine is typically turning a piece and when you go to mill the piece, the machine stops, and then the milling tool will start machining. And the list of things that you can do - milling, cross- or end-milling/drilling, angular drilling, off-center milling/drilling, three-dimensional contouring - is amazing. So you can see that when you begin to talk about axis capability on the 8/51SP, you're really talking about extreme functionality. You can put anything in the live tooling that you want. But this much is certain: We sure appreciate being able to get components complete off the machine." Prikos reminded us that X-L has purchased two GTs within the past year. "What we've found," he said, "is that due to the ease of use, we began running so many things through the GT, that it was backing things up, and it was clear to us that we needed another one."
Uptime |
|
|
With the 8/51SP, and all the multifunctions, more goes into programming and there are just more things going on, and it is a more complicated machine. But the uptime has been fantastic, and the service, when we need it, is always there right away."
Building on
Strength "These machines have kept us competitive and are allowing us to grow stronger in the medical manufacturing field. It has taken 10 to 15 years to really understand what the medical industry wants. They want tolerances in the 10ths and finishes, which are spelled out right on the print, of 16 to 32. And they won't accept anything less. And why should they?" Prikos said that Hardinge has been the cornerstone of their business. "Every piece of bar stock that comes into this building - anything that is going to be turned in any fashion starts off on a Hardinge machine, and it has been that way since we have been in business, and I foresee it continuing just that way." For more information contact: Hardinge Inc. P.O. Box 1507 Elmira, NY 14902-1507 800-843-8801 Fax: 607-734-8819 E-mail: info@hardinge.com
|
|
