Path: utzoo!attcan!uunet!ncrlnk!ncr-sd!crash!news
From: news@crash.cts.com (Usenet News)
Newsgroups: comp.sys.amiga
Subject: Seagate \
Message-ID: <4638@crash.cts.com>
Date: 16 Jul 89 08:24:20 GMT
Organization: Crash TS, San Diego, CA
Lines: 34

Here is anothers comments on Thad's "stiction" problem...

 Sub: Re: Seagates and other HD's
  To: all
From: Phil Hackett (#292)
Date: 07/15/89 04:55:07


Let me jump in here: I worked at a plant where we plated magnetic coatings onto
platters and drums for computer drives. The company I worked for also built the
heads that were used. I cannot believe Seagate would have people manually
applying a "lubricant" onto the disks with "rags". We used to plated coatings
as thin as .000005" (that's 5 millionths of an inch!), this was less than the
surface finish RMS (roughness measurements) and ANY other substance visable on
the surface was grounds for rejection (the disk). Most of the plated media
didn't require "lubrication" (one exception was the drums used in the Minuteman
Missle system....it had a Rhodium top plate) but when they do it's generally
hard Chrome plated about 25 microinches...anyways, what I have to say is just a
tiny bit of dust in ANY type of wiping material will scratch a platter
something fierce...I know, I've scraped a few in my time.....

A tidbit: at one time Telefunken had us plate 3 48" disks. We had to set up an
entire plating line just to do them! These things were massive! They were about
an inch thick and were a B**CH to handle. The disk substrate cost about
$3500/ea so we were VERY careful with them!

Phil
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