a method and apparatus for aligning and securing a spindle shaft and actuator shaft in a low - density gas - filled hard disk drive and independent of the disk drive cover is provided . a capture plate is positioned above the memory disk and is secured to the base plate . the spindle shaft and , optionally , the actuator shaft are secured between the base plate and capture plate . the capture plate may be configured to reduce vibration . this structure eliminates use of the cover to secure the spindle shaft and actuator shaft and , thereby , eliminates a potential pathway for low - density gas to escape . the capture plate may also be configured to reduce air turbulence created by the rotating disk and reduce track misregistration of the read / write element .