Minneapolis, Minnesota: One setup on one machining center does it all - high speed,
5-axis roughing, face-milling and tapping operations to create the intricate three dimensional features of a custom mold cavity. Production time is reduced up to 50 percent.
Previously, the mold's upper and lower surfaces were machined on a vertical machining
center, then moved to a horizontal machine for machining on the other four sides. Conventional workholding limited machining operations to just 3 axes, hence the need for the second machine even though the vertical machining center has 5-axis machining capabilities.
The new approach using the vertical machining center alone was made possible by
Kurt's VB 5X100 Schenke 5.1 clamping system. This new, patented device allows continuous 5-axis cutting motion of complex pockets, sculptured and contoured surfaces and intricate 3-D features with repeatable precision in a single setup.
The customer is Omnitool, Inc. of Minneapolis, Minnesota, a high precision manufacturer
specializing in designing and building large thermoform molds and match metal trim dies. "For our 5-axis machining operations, the Kurt 5-Axis Schenke clamping system is ideal," reports Dave Korton, Omnitool foreman. "It frees up a horizontal machining center for other jobs. And it allows us to really run the job fast on the vertical machining center at 270 inches per minute. Conventional workholding devices are restricted to three axes. The new Kurt system allows us to fully utilize the five-axis capabilities of our machines non-stop. There's no other clamping device out there that can handle this kind of 5-axis work."
Omnitool Reports Kurt 5-Axis Schenke Clamping System Pays For Itself On The First Two Jobs Run
Omnitool has a long history of utilizing the latest machining technologies to achieve
maximum productivity while delivering top quality results. Founded in1976, Omnitool started out solving complex, tolerance centered, structural engineering challenges in the aerospace industry. Through the years, the company transitioned into a world leader designing and fabricating thermoform tooling systems primarily for the food packaging industry. The company has long term partnering relationships with almost all of the major thermoform producers nationally and internationally. To work successfully over time with these leading companies requires the best processes, equipment, engineering and toolmakers. Omnitool has all four.
A key factor in Omnitool's precision machine work is part runs, which vary from just 1 to a high of 200 parts. These relatively short runs mean setups are frequent, time-consuming and with machining centers idled between jobs. Anything that can be done to reduce setups and increase machine utilization is a constant target for improvement.
"We watch to see what's new in the workholding area to improve our productivity," reports Korton. "Workholding is almost as important as the machining center. It can make a critical difference from one job to the next. The workholding has to suit the job as well as the machining center that's doing the work. They have to be the right match for each other. The Kurt 5-axis Schenke clamping system is new and I hadn't heard of it. Our programmer, Mike Beckmann discovered the vise on the Kurt website. We called our Kurt salesman, Mike Neeley, who brought one in. We tried it, bought it, and it paid for itself on the first two jobs."
Kurt 5-Axis Schenke Clamping System Maximizes Machining Capability Of Okuma MU 400V Machining Center
(ram saddle horizontal) mm (in) 762 (30.00)
(table front/back) mm (in) 460 (18.11)
(spindle vertical) mm (in) 460 (18.11)
(axis) in +20 110
C Axis deg 360
The day this writer visited, Omnitool had the Okuma set up with the Kurt 5-axis Schenke
clamping system to machine a 6061 aluminum part 6 x 8 x 10 in/l in. The system setup really made chips fast. Calling for 120 finished pieces, the job was run at machine speed of 9000 rpm with roughing and face milling operations done at 270 in/min. This job, according to Korton, was one of several that the new clamping system was used for, replacing conventional vises that are more restricted as to the size part they can clamp as well as the number of axes they can handle. That's because the Kurt 5-axis vise is adjustable to handle any desired clamping width, so it is limited only by the size of the Okuma's machine table. With two clamping jaws, one stationary and one movable, the jaws can be positioned at any desired distance from each other.
Actual clamping width for this Kurt system is 0.0787 inch to 9.291 inch (2 mm to 236 mm)that can be extended with optional spindle screws, a clamping depth of 0.315 inch (8 mm), height above the machine table of 6.889 inch (175 mm) with extended height options to 7.874 inch (200 mm) and 8.858 inch (225 mm).
The system is designed to mount easily on standard T-slot tables, location grid machine
tables or custom fixtures. For Omnitool, it sets up like a standard vise on the Okuma's trunnion table in about the same amount of time - less than 2 hours - taking into account tweaking the setup and part program to avoid false starts and scrapped parts. The big thing with Omnitool's application is a second setup and machining operation is totally eliminated.
Clamping Rigidity High - Equals Best Conventional Vise - Plus New Clamping System Pays For Itself On First Two Jobs Run
Korton and his machine operators said they really like the rigidity of the Kurt 5-axis
Schenke clamping system, which was proven on the first project. "We ran the machine at 9000 rpm (tops for the tool required for the task) with very aggressive roughing and finishing cuts at 270 in/min. We experienced no tool chatter or other part misalignment problems," Korton said. "Everything about the setup was rock solid." The reason for this rigidity is that the clamping system's design eliminates jaw deflection and/or part misalignment during these high speed operations. By locating the tension spindle directly under the workpiece, the clamping system's jaws do not flare out under tension and the machine table does not distort like conventional workholding. Also, the system handles a full range of workpiece configurations with
equal rigidity including blank, machined, round and irregular shapes with repeatable accuracy.
"We're very pleased with the Kurt 5-axis Schenke clamping system," says Korton. "Parts
are machined complete in just one setup so we reduce production time by as much as half. We're getting the required tolerances of ±.0002 inch with no scrapped parts plus the system paid for itself on the first two jobs run. What can be better than that?"
In addition to the 5-axis Schenke clamping system, Kurt provides integrated custom
engineered workholding systems and custom gaging systems for automated manufacturing.
Both workholding and gaging are designed around a customer's requirements with systems
available for many industries including automotive, medical and aerospace applications.
For more information about Kurt Workholding products, call 1-800-328-2565. Email:
firstname.lastname@example.org Fax: 612-623-3902. Write to Kurt Manufacturing Company, Industrial
Products Division, 1325 Quincy Street NE, Minneapolis, Minnesota 55413. Website:
For more information about Omnitool, Inc., email: email@example.com Phone: 763-535-
4240 Fax: 763-535-2064 Write to Omnitool, Inc., 3500 48th Avenue North, Minneapolis,
Minnesota 55429 Website: www.omnitool.com
For more information about Okuma Machining Centers, email: firstname.lastname@example.org Phone:
704-588-7000 Fax: 704-588-6503 Write to Okuma Corporate Headquarters and East Coast
Technology Center 11900 Westhall Drive Charlotte, NC 28278.