Xcelaero Corporation of San Luis Obispo, CA, specializes in custom vane axial and radial fans for the commercial and defense industries using state-of-theart techniques and technologies adapted from the aviation gas turbine industry to achieve the highest possible fan efficiencies.

Typically Xcelaero’s axial fan designs utilize complex shrouded vane sets, which present unique manufacturing challenges due to a lack of tool access and minimal spacing between vanes. Xcelaero is successful in part because they purchased 5-axis computer aided machining (CAM) software from Concepts NREC (CN), the company said.

“To prototype our fans we purchased a 5-axis vertical machining center and coupled it with CN’s 5-axis CAM software family including the MAX-PAC and MAX-SI package specifically for shrouded vane sets,” said Bill Denzel, Engineering Manager, of Xcelaero. “Additionally,we chose to use the CN CAM family because itmerged seamlesslywith our impeller design software.” Denzel added that three-dimensional (3D)modeling is not required to generate vane tool paths. Therefore, Xcelaero’s shrouded vane designs transfer directly from its aerodynamic design software to the CAMsoftware without generating an intermediate 3D model. This seamless transition ensures that the vane design cannot be corrupted by the 3D modeling or import/export processes. However, MAX-PAC is also capable of importing 3D CAD models.

The Challenge Before purchasing the CN CAM suite, Xcelaero used another popular commercial CAM program to create 3+2 and 5-axis tool paths to machine impellers and shrouded vane sets. This solution, however, was very labor intensive requiring several iterations to find the optimum tool approach angle and confinementwindow.Additionally the CAM software produced a patchwork of surfaces that were difficult to blend together because the tool paths were created froman exported 3D solid model that included separate individual surfaces around the blades and vanes.

The challenge was to find CAM software that improved the efficiency of tool path generation, which also integrated with Xcelaero’s existing fan design software and created continuous 5-axis blade and vane surfaces.

Solution “The CN software family was recommended to us by a consultant who specialized in programming 5-axis tool paths,” said Denzel. “The consultant had utilized several other CAM packages and recommended CN as the predominant CAM programming supplier for serious fan manufacturers.” Xcelaero’s machine shop manager spent three days training onsite with a CN application engineer. The first two days were spent introducing the basics of the Cnsoftware family and the third was spent creating code specifically for Xcelaero’s fan designs.

CN software runs on Windows 2000, XP, NT or Vista and does not require advanced processor or graphics hardware. Xcelaero’s computers were more than adequate, so the company did not have to purchase any additional equipment.

MAX-PAC uses a patented collision detection and avoidance algorithm that allows the use of larger, stronger cutting tools than other CAM systems. Socalled “lollipop” tools, with a cutting ball on the smaller shank, can even be used to reach areas that are not visible to the eye.

The CAM software automatically calculated the optimumapproach angle given the blade, tool and tool holder geometry, which significantly reduced the amount of time required to generate tool paths. The resulting 5-axis tool paths produced seamless vane surfaces particularly at the leading and trailing edges and vane root fillets.

“CN’s software included several tool path routines written specifically for blades.We prefer to use the flowline option that generates tool paths to follow flow lines around the blades,” said Denzel. “The flow line tool paths allow us to use a larger step over between tool passes and reduce the overall manufacturing time while not sacrificing surface roughness in the direction of the flow.” Return on Investment By implementing the CN MAXPAC CAM software family, Xcelaero reduced the time required to create 5-axis programs for shrouded vane sets fromone week to two days. Additionally, the tool paths generated reduced manufacturing Time by 40 percent by eliminating the need to flip the shrouded vane set over. And, Xcelaero virtually eliminated the production of scrap parts during the initial prototyping process.

For more information contact: Concepts NREC 217 Billings Farm Road White River Junction, VT 05001-9486 802-296-2321 www.conceptsnrec.com Xcelaero Corporation 4540 Broad Street, Suite 120 San Luis Obispo, CA93401 877-925-2376 info@xcelaero.com www.xcelaero.com