RL drive lubrication
oldcpu at rogerwilco.org
Tue Apr 11 17:38:54 CDT 2006
Tony Duell wrote:
>> Yes, I left the motor, cam, and switch. I just removed the actual brush
>> arm from the shaft, leaving everything else so that the logic would
>> 'think' the brush is still in place.
> Sorry if some of my questions were 'going over the bleeding obvious'...
> All too often I've found I've made assumptions about what the other chap
> has or has not done, and wasted a lot of time going along the wrong path.
No worries. It's good to have someone look over my shoulder helping to
make sure I'm not my usual complete idiot! :) Thanks!
>>> See if the signal is stable and has the
>>> right frequency (compare it with the same signal in another working drive).
>> Excellent advice. I will try this. I do have a scope, though I'm more
> I think the printset is on Bitsavers (if not, I have it). If you can't
> find the right point to look at this signal, let me know, I'll get out
> the prints and tell you what pin of what IC to look at.
I'll check bitsavers. If I can't find what I need, I'll come back to you.
> Another 'obvious' question : You have made sure the head lock is not
> fitted on the 'dirty drives'? That would stop it going ready.
Another valid question. Yes, indeed, the head/actuator locking plate
has been rotated to the 'un-locked' position. This might be the place
to mention that these two 'dirty' drives had the heads already locked at
the time of acquisition. I'm doubtful that they have been used in many,
many years, since this indicates that the former owner had not tried them.
I wonder....could the heads, having been in the retracted position for
so long (years and years), be kind of 'glued' in place by dust/grime/dry
grease, thus no READY indication? Hmm...a question: is it advisable to
move the heads manually to test this, or am I better off keeping my fat
fingers out of the head actuator area (which I've religiously done to date)?
> I think there's some kind of grounding brush on the spindle, visible
> under the little cover on the bottom of the drive. That can, I suspect,
> make odd noises, but it shouldn't stop the thing going ready.
This, too, is a good point. I do recall reading about the grounding
'point' in the Maintenance Manual. I'll check this also.
>> I was just worried that there might be some vertical alignment issues if
>> the spindle assembly wasn't put back correctly. I have no idea if there
>> are shimming or 'leveling' screws that would assist in making sure that
> There are no leveling screws, and AFAIK no shims either. Vertical
> alignment is not _too_ critical -- the heads fly rememebr, so will align
> themselves to the platter surface. I think all you have to do is make
> sure the mounting faces on the chassis and spindle housing are clean, put
> the spindle in place and tighten the screws evenly.
Well, this is good news, at least. I hope not, but I may end up
removing the spindle eventually, and this let's me be more comfortable
about that possibility.
Again, thanks for the advice, Tony. It might be a day or two for me to
get back to this project, but I'll post my results as they are gathered.
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