Challenge: Machine 60 pcs. from a solid block; the finished part has a flange under 1/8" thick, and the flange must be flat and the cylinder round to within a few thousandths. The nature of this material causes it to warp during machining -- as material is removed from one side of the block, internal tension becomes unbalanced, and the block spontaneously bends. This material also tends to be abrasive and generate heat, and can weld to the tool. The material is very expensive, so scrap must be minimized; and we were given only 10 days to complete the run.

Solution: To avoid warping, we used a combination of three techniques: We used a straight-flute mill, we used conventional milling (rather than climb milling), and we removed material from every side of the block, so that final piece essentially came from the middle of the block. Work holding was especially challenging, and we used the features in the piece itself that had already been machined to hold the piece for subsequent operations. A high-pressure blast of chilled coolant was directed onto the solid-carbide tooling at all times.