High-Performance Composites

MAY 2014

High-Performance Composites is read by qualified composites industry professionals in the fields of continuous carbon fiber and other high-performance composites as well as the associated end-markets of aerospace, military, and automotive.

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M A Y 2 0 1 4 | 5 3 FEATURE/MACHINING UPDATE To handle the excess material buildup in the metal hole's sidewall that results from the larger chips, Mapal employs an innovative single-blade reamer. "Normally, reamers have many blades, at least three to four," Mueller-Hummel explains. "Ours has two guide pads and only one cutting edge." By incorporat- ing the single-blade reamer design into the drill tool, material that accumulates and puts a "squeeze" on the tool is re- moved — the guide pads move the ma- terial inward and then the reamer then cuts it off. "So we have refned the tool to perform a true cutting operation on its sides," Mueller-Hummel summariz- es. There is no "jamming" at the cutting edge and heat is further reduced. Dealing with different diameters One problem, however, still remained. When Mapal frst started working with Bombardier, the aircraft manufacturer wanted to maintain H8 hole tolerance in stacked materials, but the metal hole was consistently 25µm (0.001-inch) larg- er in diameter than the composite hole (see drawing, bottom of p. 49). The solution was a second reamer. "Our idea was to put a microreamer on the drill tool," Mueller-Hummel recalls. "By adding a small, very thin step of 10 µm to 50 µm [0.0004 inch to 0.002 inch], this additional cutting implement would only touch the composite and make its hole edge equal with that in the metal" notes, "but after a couple of days, the f- bers fex back into the hole and you have a smaller diameter. Everyone thinks this is a problem with composite materials. It is actually a problem with the drill tool design." The Micro Reamer is evenly CVD-coat- ed so it works like a grinding tool, remov- ing the uncut fber. (See photos, p. 54). At frst, Mapal thought the Micro Reamer would only work when the (see photo at left). Now trademarked as the Micro Reamer, this feature also solves the chronic problem of "burring," the term for the rough edge that remains on the composite after it has been drilled. In composites, the burrs or "hairs" remain because fbers aren't sheared cleanly. Notably, as the drill turns, the heated matrix will "smear" and trap ragged fber ends against the hole side. "At frst, it ap- pears this has worked like in metals," he Microreaming innovation The concept of Mapal's Micro Reamer is illustrated here, although its actual 1 mil projection would not be visible without magnification. Source: Mapal Whether you have an existing CMM device or about to purchase one, Verisurf-X is the only software you need. With its 3D CAD-based architecture, fl exible reporting options, and ease of use, Verisurf-X will reduce training time and increase productivity, right out of the box. No matter what you are making or measuring, Verisurf-X provides the power to drive your devices, reduce cost, improve quality, and streamline data management – all while maintaining CAD-based digital workfl ow. www.verisurf.com • 866-340-5551 Learn more about the power of Verisurf-X by visiting our Website, or call for an onsite demo. There are many CMMs. One software makes them more powerful. 0514HPC_MachiningUpdate-OK.indd 53 4/22/2014 3:22:47 PM

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