CESCO Magnetics, Santa Rosa, Calif., produces a variety of magnetic filters used to remove ferrous and hardened stainless steel impurities in food processing operations. Because CESCO specializes in products for sanitary applications, the company works almost exclusively with stainless steel.

CESCO’s Model 115 Magtrap units are engineered to handle foods such as cottage cheese and fruit preserves that require gentle flow conditions. The food product flows through the trap where it is diverted onto a flat plate magnet that catches the impurities.
CESCO president Marc Truslow said the Model 115 is “unique; it’s not like anybody else’s design,” noting that “this unit has done very well overseas.”

CESCO makes two different sizes of the unit, starting with 6.5"-dia. or 8.5"-dia. 316 stainless steel bar stock. Until recently, the bodies were roughmachined in a sequence of separate operations on a 2-axis lathe and a 4-axis horizontal mill. Although running the two machines in parallel consolidated cutting time, part handling slowed throughput.
First, each part was put through two turning operations, between which it was flipped in the lathe chuck. Then the part was moved to the mill where the main cavity and pockets were milled on one side. Finally, it was manually repositioned for milling of side angles.

In addition, metal-removal productivity was limited. The 4-axis mill and its CAM software restricted CESCO to the use of a 1”-dia. endmill, at the largest, to create radii in certain pockets. Less-than-optimal tool holding rigidity also precluded aggressive cuts.

When CESCO moved its manufacturing operations from Santa Rosa to Georgetown, Tex., in 2006, it took the opportunity to revamp its manufacturing processes. Before and after the move Truslow received tool application assistance from BIG Kaiser sales representative, David Frank of Next Generation Tooling LLC. Truslow said he continues to consult Frank because “When we were struggling with something he would always bring in whatever or whomever we needed to help us out. He’s been an asset to us.”

Frank said roughing the 115 body isn’t simple; “It’s not just some chunk of steel where they are taking basic cuts. They are doing some fairly elaborate pocketing to get this part roughed out.” He said Truslow has been manufacturing the 115 body for about seven years and has applied “virtually every competitive endmill in this application; he always has been trying to find the next better tool.”

To speed machining of the 115 body as well as other products, CESCO purchased a 5-axis Mazak Integrex e410 HMC featuring dual spindles. Truslow said it is “pretty slick; it can mill at any angle that you want.” At Frank’s recommendation, the machine was ordered with the capability to accommodate the BIG-PLUS dual-contact tool holder system. The holder and spindle design boosts rigidity by maintaining simultaneous contact on both the tool holder’s flange and spindle faces.

Frank also suggested the application of BIG Kaiser’s Fullcut Mill indexable endmills, which are engineered for multi function milling operations including ramping, helical, shoulder and plunge milling. The endmills feature sharp inserts with positive axial and radial rake for lower cutting forces, as well as an eccentric relief angle that enhances strength and toughness. Frank said the rounded relief on the insert “won’t rub, but it provides extra strength.” To further boost strength and rigidity in the tough stainless milling operation, CESCO ordered the endmills with an integral CAT40 BIG-PLUS shank.

Truslow said the Mazak HMC minimizes workhandling: “It allows us to put the part in and remove a finished product. It transfers the part between the spindles so no manual interaction is required.” The 5-axis capabilities of the mill, combined with the Gibbs CAM software CESCO also acquired, permits using an endmill as large as 1.25"-dia. In addition, the Fullcut Mill endmills, teamed with the enhanced rigidity of the BIG-PLUS holders, allow larger depths of cut.

The new tooling, Frank said, is the key to increased productivity in the roughing operation. The 1"-dia. endmill used previously ran at 2,383 RPM, 43 IPM, and a 0.05" DOC, for a metal-removal rate of 2.15 in3/min. Now, the 1.25"-dia. Fullcut Mill endmill, tooled with three positive-rake multilayer PVD-coated inserts, runs at 1,800 RPM, 28 IPM, and 0.1" DOC, providing an MRR of 3.5 in3/min. Frank noted that the 38-percent increase in MRR came despite the soft, abrasive, and gummy nature of the 316 stainless workpiece material.

Altogether, Truslow said, the new manufacturing methods produce significant time savings. When roughing the parts, “on the 6.5" body we’re saving 30 min. per unit; on the 8.5" body we’re saving 50 min. per unit,” he said. “We do hundreds of these a year. You can see the savings, and this is for only two of the parts we make.”

Truslow said CESCO continually seeks ways to improve productivity. “We’re not a large shop,” he said. “We do smaller runs, so we are happy to try out anybody’s new products. It saves us some money, but it helps those suppliers out as well. We’ve been doing that for a long time. We’re always apt to try something new if we can make it work better.”

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Any other success stories with the full cut inserts?