PSL fabricated two copper external cones for the CLEO III Silicon Detector. The cones were among the most challenging machining projects ever undertaken by the PSL instrument shop. The cones provide cooling for the electronics of the detector and act as support and locator for the silicon detectors. Because each cone was produced from one large 25 cm (10 inch) diameter piece of high purity, oxygen free, high conductivity copper, and had hundreds of features, it was extremely complicated and required careful planning and precise machining. Initially, the lathe was used to roughly shape the inside and outside, resulting in the removal of about 70 kg (150 pounds) of material. Next, the copper was moved to the CNC Hermle milling machine. CNC Specialist Bill Koenig machined 18 facets on the inside of the cone and 230 tapped holes, some tiny and at difficult angles. The machining, which took over six weeks on the CNC Hermle, was possible only because of the 4-axis capability of the Hermle. The machining went very well with no breakage or problems with distortion. According to Bill Koenig, one of the toughest challenges was verifying the tool paths using Mastercam. After the machining on the Hermle was done, the shaping of the cone was completed on the lathe. The cone was then sent out to have the wire EDM done. PSL also made the internal cones.

The image is of a cone near completion, with cooling tubes about to be attached, and another image looking down the bore. There are many more images available, at Purdue.

Visit the CLEO home page at Cornell, or Purdue.