11 Apr
2006
11 Apr
'06
11:51 a.m.
pretty good condition, cleanliness wise. I replaced
all four course
filters, and
checked the absolute filters, which were actually okay even in the dirty
drives.
The RL airflow is rather nice in there's air circulated round the disk
pack, the absolute filter and the outside of the 'heat exchanger' tubes,
and a second airflow through the prefilter, the inside the of the tubes,
and out over the heatsinks and the PSU fan. While the first system is not
sealed, there is less interchange between it and the 'very dirty' air
than in most drives, so the absolute filters last longer.
Because all of these have been powered off for many years, I opened them
up and
pulled the power supply for a session with my capacitor reformation rig
after
cleanup. With that successfully accomplished, and finding that all
voltages were in
line, everything was reassembled. During the wait for the capacitors, I
cleaned the
interior pretty well with a vacuum and Windex. As a side note, three of
the drives
still had the platter brushes installed, and since I already had each
drive opened
for power supply checkout, I went ahead and removed the brush assemblies.
What did you remoce? Just the brush tips? Did you leave the motor, the
microswitch, and the operating cam? Without those, you might have
problems getting the drive to go ready.
Fortunately, the 'clean' set of drives are now fully functional, having
been tested
with one of the 11/23s.
Unfortunately, after mounting and LOADing a known good disk cartridge,
neither drive
from the 'dirty' set will show READY after spinup. Though the details
You do have these cabled to a working controller, I trust? You need the
clock signal from the cotnroller for the drive to spin up and go ready.
are a bit
different, each drive emits a very noticeable sound, kind of a
whining/rumbling sound
(not squealing), that I think is indicative of dry bearings in the
spindle, the
spindle motor, or both. I wonder if dragging bearings are preventing
the drive from
becoming READY due to uneven RPM?
It's possible, but unlikely. I suppose you could start by looking at the
output of the sector transducer (posibly after the amplifier circuit).
That's what the drive uses as a speed reference anyway (the motor in the
RL is not locked to the mains, unlike most other demountable hard drives,
there is no change for 50/60Hz). See if the signal is stable and has the
right frequency (compare it with the same signal in another working drive).
I've scoured the online documents for possible
information regarding RL
drive
lubrication, but I can't come up with anything that suggests 'in the field'
lubrication options. The RL01/RL02 Maintenance Guide talks about
disassembly and
Field Replaceable Units, but nothing about lubrication.
So a few questions for those in the know:
Could dragging bearings be the cause of no READY indication?
Has anyone had any experience lubricating the appropriate assemblies in
an RL drive?
I would not try to lubricate the spindle bearings. You'll never get it
apart anyway (t's pressed together, and you have to maintain mecahnical
balance, etc. There may be a ferrofluid seal in there too). The risk of
contamination to the disk/heads is too great.
It shouldn't hurt to take the spindle motor out, take it apart (obvious
through-bolts) and oil the bearings. I think they're phosphor-bronze
bushes, not ball races, in which case you want a medium machine oil on them.
If so, what lubricant is recommended, where is it
applied, and how?
Removing the motor for lubrication is no problem, but I wonder if
removing the
spindle assembly would then necessitate a head alignment once it's back
in place?
No, you can remove and replace the spindle without upseting the heads. In
any case, the RL drive has an embedded servo burst in each sector header,
so head alignemnt is quite easy (you need a 'scope, but no special
alignment disk, any normal disk will do).
-tony