A disc assembly in a disc drive includes a hub rotatable about a central axis. Pluralities of disc elements are mounted about outer periphery of the central axis of the hub. An annular shaped disc clamp is located about a first axial end of the hub, the annular shaped clamp holding the outermost disc to the hub by a series of equally spaced fasteners along an inner diameter of the disc clamp. The improvement therein consisting of placing an offset angle on the underside, or disc-to-hub contact area. The offset angle sloping from the inner disc contact point outward to the end of the clamp such that application of pressure during clamping will make a uniform contact area along the clamp surface as the clamp fasteners are tightened to secure the clamp to the hub. This improves flatness, axial run out, reduces repeatable run out and increases reliability.

 
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> Disk drive pulse width modulating a voice coil motor using model reference current feedback

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