The Ohio State University

EFFECTS OF OPERATING PARAMETERS ON LATERAL TAPE MOTION FOR MAGNETIC TAPE IN AN ADVANCED LINEAR TAPE DRIVE

Andrew Eric Wright
M.S. Thesis,
Department of Mechanical Engineering, May 2006

ABSTRACT

The drive for increased storage capacity in today’s magnetic tape cartridges has created a continuing need to improve the understanding of the tribological performance of magnetic tape. One important area of ongoing tribological research is lateral tape motion (LTM). Excessive LTM can cause problems with track misregistration where written data cannot be read back accurately. Tape and drive manufacturers are increasingly challenging the tolerances of LTM in their quest for increased data storage. While the importance of studying LTM is known, many of the sources and reasons for increases in LTM are unknown. This provides the motivation for the work presented.

Several studies are completed to identify sources and contributions to increases in LTM. The first such study is a baseline look at different types of tape under nominal conditions. Six different types of tape are used throughout the studies. These include commercially available metal particulate (MP) tape, an experimental thin MP tape, and four advanced metal evaporated (AME) tapes. A multitude of different operating parameters were identified for analysis in hopes of learning more about their role in LTM generation. Some of these parameters include operating tension and speed, as well as head and bearing setup. Additionally, tape quality metrics such as edge quality and tapes from staggered packs were studied to determine their contributions to LTM.

The results show that all of the tapes with the exception of a negatively cupped AME tape perform well at nominal operating conditions. Tension was shown to significantly impact LTM at low settings in some tapes due to a lack of surface roughness and tape edge pinning. Operating speed was shown to have a negligible impact on LTM. Changes to the head zenith angle and wrap angle of the tape appear to have a significant impact on LTM generation, while the air pressure used in the tape transport bearings does not. Staggered tape packs and a bearing placement study show a minimal increase in LTM at the head when changes occur “downstream” in the tape path. The results from these studies allow for conclusions to be drawn, as to which tapes and settings optimize performance based on minimizing LTM.