Fluke Metal Products, Inc. (Bothell, WA) had experienced rigidity issues with its rotary tables and replaced them with more rigid Nikken rotary tables. Fluke, founded in 1957, employs a staff of 50 at its 15,000 ft.2 (1,393-m2) facility. The shop manufactures precision-machined parts for the medical device and implant, electromechanical and aerospace industries. Fluke produces precision workpieces from a single prototype part to quantities of 10,000 parts per job.

"In our industry, it all comes down to how rigid the hold is when you’re in the cut,” explained Larry Fluke, president, Fluke Metal Products. Not every rotary table is of equal rigidity. In fact, rigidity issues with the company’s last rotary tables prompted Fluke to switch to the Nikken brand. All of Fluke’s four- and five-axis Kitamura CNC milling machines are installed with Nikken rotary tables, which replaced less rigid existing rotary tables. The more rigid Nikken rotary tables enabled Fluke to achieve greater machining accuracies and speeds in producing its parts.

Recently, Fluke was approached by RJC Enterprises LLC (Bothell, WA) to produce a medical device quickly and affordably. An OEM supplier of fiber optic sensors and systems for medical applications, RJC components were being produced in a shop that did not have 5-axis milling capability. "It was definitely a matter of response time. Fluke builds parts sooner and less expensively due to its rotary tables,” explains Jim Hartl, manager of product development, RJC Enterprises.

Specifically, RJC required the milling of a fiber optics pressure assembly, or optic block, used in an intra-aortic balloon catheter. This device consists of various components that are installed in relation to one another to assist with the flow of blood in patients with weak hearts. The portion of the assembly manufactured by Fluke consists of a two-piece base and cover. Machined from 6061-T6 aluminum, the final part dimensions are approximately 1.28” x 1.3” x 0.66” (32 x 33 x 16.7 mm). General dimensions are ±0.003” (0.08 mm) with critical features ranging from 0.0002” to 0.0005” (0.005-0.013 mm) total tolerances.

"We machine RJC’s part complete - five sides with one operation - for reduced costs, while holding the integrity of the dimensions,” continues Fluke. "Nikken rotary tables hold 0.0002” (0.005 mm) profiles, and that is impressive.”

For four-axis machining, Fluke uses the Nikken CNC180-FA rotary table. This compact model features a faceplate diameter of 180 mm and rotation speeds of 44.4 rpm. It is suitable for a wide range of applications from a small drilling machine with simple indexing to full CNC positioning on machining centers in high-volume production. Nikken’s single-axis back-side motor mounted 5AX130-FA rotary table is used for five-axis machining at Fluke. While this model also features

a faceplate diameter of 180 mm and rotation speeds of 44.4 rpm, it is designed for machine tools with limited space in the Y-axis and is suitable for indexing and rotational milling. "Rigidity, accuracy and speed of rotation are the top three things we look for in a rotary table, and Nikken fits them all,” states Fluke.

Quality casting material in combination with a patented ground carbide worm screw mechanism provides a balanced environment for rigid machining. The carbide worm system in the rotary table uses a carbide wormscrew 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 wormscrew consists of a less brittle V-grade form of carbide, while the wormgear is ion-nitrided to a depth of 0.1 mm and an external surface hardness of Rc 68. These properties, as well as a steel way hardened to Rc 58-60, all work to enhance system rigidity and longevity.

Nikken rotary tables are also highly effective in machining increasingly popular 6AL-4V Titanium. Stronger than steel, yet lighter than aluminum, this titanium requires a true rigid set to achieve desirable finishes.

To learn more about Fluke Metal Products, Inc., contact them at 10223 Woodinville Drive, Bothell, WA 98011. 425.485.9666 - www.flukemetal.com