Productivity is up by 15 percent, tool life is up 20 percent and part cost is down 20 percent for face milling, drilling and boring operations at Engel Machinery Inc., York, Pennsylvania. The savings have gradually built up since the Austrian company started manufacturing operations in the United States six years ago. The organization is a world leader in manufacturing injection molding machinery for the plastics processing industry. The three gains are based on constant upgrading of tooling and procedures over the years.
Key upgrading involved a tooling standardization program with milling inserts, milling cutters and drills.
At the outset, when the company decided to establish a manufacturing base in this country it faced a problem.
The problem: Set up an efficient machining capability a continent away from their main facility, with no sacrifice in quality. And, get the assurance they were using state-of-the-art tooling with no breach in supply and service.
The solution: A three-way partnership between the company, a single tooling supplier and its local distributor.
When the company decided to produce its product here it turned to Sandvik Coromant, in Fair Lawn, New Jersey, for its tooling needs. The third member of this team was Petry and Morrow, distributors.
Today the partnership is as sound as ever. Beside the gains in productivity, tool life and processing economics, Engel also cut tooling inventory requirements by more than half. What used to require 30 different insert grades and sizes are now met by 15 insert grades and types from a single vendor. Paperwork has been reduced as well, and there is never a shortage of any needed tool.
"We had to have a reliable source to function as back-up when it came to metal cutting. Petry and Morrow gave us a commitment to support our qualified machining operation," said Ralph Lees, Engel vice president and general manager.
"We knew they had the complete product lines we needed as well as technical support from Sandvik. Also, they provided a standby stock, minimizing our in-house tool inventory requirements," commented Kurt Schuessler, manufacturing engineering supervisor.
"Local stocking gave us a comfort factor, allowing us to concentrate on our main objective which was, and is, to build and ship quality injection molding machinery profitably and efficiently," added Mr. Lees.
"Almost all of our machining methods are based on drawings received from Austria, carried out on our own machines. It is important that we work to the same standards as our home base. During the past six years we've steadily built our machining capability. We have had a reliable source over the years," he commented.
Engel uses two major machining centers, a large Giddings and Lewis and a Scharmann, to machine platens and bases for the injection molding machines. A team of designers, programmers and tooling specialists work together to establish methods and tools. The parts are large G65/GGG40 cast iron assemblies. They vary in size and machinability and are fabricated from flame-cut pieces and housings.
The Giddings and Lewis machine handles the larger elements, up to 58 tons, while the Scharmann machining center handles the smaller platens and bases. The large cast iron components have unusually close tolerances and surface finish requirements. Machining surfaces must be parallel within 0.0008 inch, square within 0.0012 inch, and with a surface finish of N7.
"Tuned Teeness anti-vibration boring bars with the Varilock system combined with T-Max 145 provides the accuracy and stability needed. This system is used for face milling and twin-edge boring, taking deep cuts per pass. Boring involves long tool overhangs, so the Teeness anti-vibration bars really pay off," according to Herb Harbold, group leader of the large machining centers.
"We learned quickly that these high-tech machining centers need a high-tech tool solution," Mr. Harbold said. "Some of the overhangs are extreme one with full extension spindle and tool reach of 60 inches. This meant a vertical sag of 0.011 inch. Stability and rigidity are a must. We had some early problems with the hydrostatic bearings in the machining centers, but the tuned Teeness boring bars took care of that."
For square shoulder milling, the company uses the new Coromill 290 as a general cutter for cast iron and steel. This grade complements the 145 cutters for face millling. For many of the grooving cuts and interpolated internal slots, the Coromill 331 slotter is used. This cutter is designed to give much longer tool life and maintain accuracy, even at very high cutting rates.
Waveline inserts are used throughout these operations in carbide grades GCA and H13A. Modu-mill handles the large diameter--6 to 8 inches--face-milling. The nearly 80-inch wide platens are face milled in several passes at high speed, removing up to 1 1/2 inches of stock. The Modumill cutters achieve a face mill surface as close as possible to a ground surface. Surfaces are smooth with no evident pass overlaps.
Both the Coromant U-drill and Delta drill systems are used extensively in this facility.
Here are specific examples of how the various tooling is performing: For the heavy roughing of cast iron with tough scaleface milling with T-Max 145, 8-inch diameter with 13A inserts at 366 sfm cutting speed. Feed is 26.5 ipm with a depth of cut of 0.24 inch; that is about 15 percent faster than before, yet edge life is up as well. For the roughing of cast ironface milling with T-Max 145, 8 inch diameter with WL/GCA inserts at 586 sfm cutting speed. Feed is 27 ipm with a depth of cut of 0.24 inch. For the finishing of cast ironface milling with a Modumill, 10-inch diameter, 15-degree cutter with WM/GCA Waveline inserts. The cutting speed is 800 sfm with a feed of 27 ipm and depth of cut of 0.012 inch. Edge life is 20 percent longer than before, at equal or slightly higher removal rates. For OD recessing Interpolated side and face milling with Coromill 331, 5-inch diameters and H13A inserts. Cutting speed is 330 sfm with a feed of 6 ipm. Depth of cut for this step was the maximum of the insert capability. Again, edge life is about 20 percent higher than before.
Since launching the U.S. facility, Engel has seen an expanding role in manufacturing its own components. Previously, most parts for this sophisticated line of machinery were shipped from Austria ready for assembly here. A steady increase in sales--up to 30 percent annually--provided impetus to take on more of the manufacturing locally. The molding machines made here range from 500 to 4,000 tons and maintaining their quality is a challenge. Partnering with a leading tooling company and a service oriented local distributor has paid off for everyone. MMS