Dynamic disc pack balance correction

The present invention relates generally to the field of disc drive data storage devices, and more particularly, but not by way of limitation, to an automated assembly process of a disc drive assembly which includes a dynamic balance correction station. A method for automatically correcting the dynamic imbalance of a disc pack of a disc drive, the disc pack conveyed to a first selected position in a balance correction assembly station where a rotary positioner lifts and rotates the disc pack to a reference position for the attachment of weighted shims to the disc pack. A shim selector assembly delivers a selected shim, and an end effector transfers the selected shim to a shim attachment assembly. The shim attachment assembly rotates and spreads open the shim so that the disc pack can be receivingly engaged thereby, and the shim attachment assembly releases the selected shim to lockingly engage the disc pack. A flipping assembly reverses the disc pack for placement of another selected shim to the other end of the disc pack, as required.