I can't imagine anyone being concerned about 3-1/2" drives, but with these
old 8" drives it is risky to put greasy lubricant on the lead screw. If you
do need to lubricate the nut, then do so with some powered molybdenum
disufide. That's what they put in grease to make it slippery, and it does
well without the grease. If you put that on the nut and leadscrew,
remembering that the nut is steel and the leadscrew is some form of
polycarbonate, I'd say that doing everything to clean the leadscrew and nut
that is available to you, then lubing it with a LIGHT coat of (one drop for
every three drives) of WD40, then adding about 1/4 tsp of moly-disulfide,
will probably do the trick. If they ever get sticky, clean and relube the
lead screw and nut this way. Moly-disulfide is MUCH more slippery than
graphite. It's also not in the least bit abrasive.
Dick
----- Original Message -----
From: Tony Duell <ard_at_p850ug1.demon.co.uk>
To: <classiccmp_at_classiccmp.org>
Sent: Thursday, April 13, 2000 12:11 PM
Subject: Re: Lubing Shugart 800,801's?
> >
> > I've been sorting through a large pile of Shugart 800's and 801's here,
> > and many of them have goo on the head stepper lead screw. It looks
> > like white lithium grease, undoubtedly put there by a previous owner
> > or all-thumbs tech, as the Shugart manuals say (section 3.3):
> >
> > Do not lubricate the SA800/801; oil will allow dust and dirt to
> > accumulate.
>
> This being the same manual that tells you not to clean the heads....
>
> Seriously, while excessive lubrication, and lubrication in the wrong
> place, will cause all sorts of problems, I am convinced that carefully
> lubriacting leadscrews (and cleaning off old lubricant and replacing it)
> will reduce wear. Ditto for spindle bearings.
>
> FWIW, every other drive manufacture's service manual for drives with
> leadscrews that I have suggests that you lubricate these leadscrews
> (Sony, Teac, etc).
>
> > However the goo got there on the leadscrew, it's so thick now that it's
> > quite difficult to turn it - not only is the stepper motor not up to the
> > job, I can barely turn it by hand in some cases.
>
> Ouch... Somebody used the wrong lubricant....
>
> >
> > I have found that "Liquid Wrench" (yes, that stuff you get at the auto
> > parts store) does a pretty good job of at least softening the goo
temporarily,
>
> Most greases disolve in propan-2-ol (aka head cleaner ;-)). That's what I
> normally use to shift old lubricant from such positions.
>
> If it's not too bad, then you can often remove it using propan-2-ol and a
> q-tip (cotton bud). If it's turned to glue then you have to dismantle
> things. And IIRC the SA800 is nasty because you have to lose alignment
> when you do this (unlike some smaller drives where you can slip the head
> carriage sideways off the leadscrew).
>
> > enough so that I can actually run the drive through diagnostics,
> > but eventually the solvents evaporate and I'm left with thick goo. Is
> > there an easy way to clean this goo off without completely disassembling
> > the stepper motor/leadscrew assembly and doing the subsequent
realignment?
>
> I think you're pretty much stuck with having to do a full alignment :-(
>
> -tony
>
Received on Thu Apr 13 2000 - 14:33:51 BST