Part Name: Printed circuit board enclosure

Material: 6061 aluminum

Challenge: To minimize cost while milling from a solid block to a finished part with walls .063 thick. The finished part contains a .92" deep pocket with 1/16" radius internal fillets in the corners. Over 2/3 of the block must be turned into chips. The finished part contains 72 holes, 22 of which are tapped, and there are features to be machined into all six faces of the block.

Solution: We peripherally mill the five external sides in the first VMC operation in one chucking, to establish perpendicularity of the sides. In pocketing, we clamp onto just .2" of material on the bottom, to avoid collapsing the side, so we have to use controlled clamping pressure and special milling techniques to reduce sideward forces on the work piece. We use true high-speed machining with solid carbide mills to reduce the cycle time to 50% of what it was originally, while holding the bearing hole size to ± .0003. At our suggestion, our customer allowed us to sequentially serialize each enclosure to aid them with quality control/traceability, an enhancement we were able to add with no added cost to the customer.