Disk platters and water (was: Re: NOVA4 6070 disk booboo)

[Paul Koning]

>>>>> "Jay" == Jay West <jwest at classiccmp.org> writes:

 Jay> You wrote...
 >> When I was in college, we had an IBM 1311 that sprang a leak
 >> (hydraulic head actuator...) spraying hydraulic fluid all over the
 >> system pack.  The FE repaired the drive, wiped the heads and pack
 >> with solvent, and started things back up.  Worked just fine.

 Jay> Wonder what the head-disk gap was on a drive of the IBM 1311
 Jay> vintage.

Probably not dramatically larger than that of the RK05.  I don't
remember the number.  It was shown on a drawing on the disk pack bags
that DEC created to remind people not to put fingerprints on the
platters.  I remember it showed a fingerprint, a dust particle, and a
hair, drawn to scale next to the head height.  The fingerprint was
about 3-5x the flying height, so measure a fingerprint and find
out...  It also was perhaps 1/50th of a hair.  So perhaps a few
micrometers?

	paul