A small niche market exists for the machining of large parts. Shops committed to tackling such projects are generally accepting of the extra time and labor that are required to complete them. More set-ups simply come with the territory it is believed. Some job shops, however, are rethinking and challenging conventional large-part machining techniques.
One such job shop is Technox Machine and Manufacturing Inc. of Chicago, Illinois. In business for 35 years, Technox employs over 30 machinists and occupies two Chicago-area facilities totaling 75,000 square feet. This full service machine shop specializes in machining parts of up to 28' long. Parts regularly machined at Technox include rings, dial plates, drums, shafts, segments and castings for industries from steel mill to food processing.
Until five years ago, Technox was machining large parts on 3-axis machines that required multiple set ups and rotations by hand. However, the decision to integrate rotary tables into existing machines has cut production time in half.
Integrated into a Mori Seiki MV-1003 VMC, Nikken's CNC601 Rotary Table enables Technox to machine four .375" x .750" keyways into a drive shaft (4140 heat-treated material, hardness 269/321 BHN) at tolerances of +.001"/ -.000". "Previously we would rotate this part by hand. Now it rotates for us, we cut it and it rotates again. And we now have a more accurate product," explained Jason Herff, sales manager, Technox. It is critical that the keyways are perfectly aligned on the drive shaft. The use of a rotary table eliminates the risk of misalignment due to human error when rotated by hand.
What's more, the incorporation of rotary tables has provided additional opportunities for the shop, as they can provide a wider range of machining capabilities. "We bought the rotary tables with more opportunities for us in mind, as well as more opportunities for our customers," stated Herff. "When some customers would first come through the shop and see a rotary table, they would say, "You have that? I can use that. Now I point it out to customers."
With the CNC601, it is now possible for Technox to machine a ribbon screw used in underground boring applications. The screw is designed to push cutter heads forward and engage the tunnel face. Every tunnel-boring machine uses several screws, one for each cutter head. With beginning dimensions of 16" O.D. x 8" I.D. x 26" long, the 1020 HR forging material is machined to a finished size of 15.750" O.D. x 8.250" I.D. x 25.875" long with 2.500" flights, at tolerances of +/-.005". The part goes from a pre-machining weight of 1,200 lbs to a post-machining weight of about 300 lbs. "We could not have made this part without a rotary table," said Herff.
A Nikken CNC401 Rotary Table installed on Technox's OKK VM7III VMC has even enabled the shop to bring outsourced jobs in-house. Previously the shop had outsourced the machining of a flesh-stripping ring for the meatpacking industry. Today Technox performs machining operations for this part in-house, on the rotary table-integrated OKK, and saves thousands of dollars. The rotary table operates in conjunction with a Lyndex-Nikken AngleHead and a Mimatic Indexable Cutter to cut teeth into the ring of D-2 tool steel. No finish machining is required. Final dimensions of the ring are 10.269" O.D. x 9.890" I.D. with tolerances of +/-.001". Technox produces 600 of these parts per year in 100 lot segments for customers worldwide.
With Nikken Rotary Tables, Technox affordably achieves the performance and precision of a dedicated (4-Axis), machine. They also have the flexibility to use the machine for both 3-axis and 4-axis work. "Technox can do full 4-axis simultaneous machining exactly like, and to the same accuracy as, factory built full 4-axis machines - at a fraction of the cost," stated Steve Baier, regional manager, Lyndex-Nikken. Lyndex-Nikken also provides the installation and interface integration of the Nikken Table into the Machine Tool's CNC Controller.
Lyndex-Nikken's Rotary Tables are built for rigidity. These rotary tables integrate the finest casting material with a unique patented ground carbide worm screw mechanism. This results in a balanced environment for unprecedented rigid machining.
The carbide worm system uses a carbide worm screw and ion nitrided worm wheel, rather than a conventional bronze or bronze alloy actuation mechanism. These result in a reduction of friction and wear by up to eight times. The worm screw consists of a less brittle V-grade form of carbide, while the worm gear is ion nitrided to a depth of 0.1 mm and an external surface hardness of 68 Rc. These properties, as well as a steel way hardened to 58-60 Rc, all work to enhance system rigidity and longevity.
"Nikken Rotary Tables have opened up our capabilities. They allow me to find more work, different types of work - and definitely help us to increase sales," continued Herff. "A 35 year-old business like ours is like a person - you're never too old to learn new things."
For more information, visit www.lyndexnikken.com, or contact Lyndex-Nikken Inc., 1468 Armour Blvd., Mundelein, IL 60060, Phone: (800) 543-6237. To learn more about Technox, contact Technox Machine and Manufacturing Inc., 2619 N. Normandy Avenue, Chicago, IL 60707, (773) 745-6800, www.technoxmachine.com.
