Newfdog said:
I just purchased an external harddrive case and installed a
200G harddrive in it. When placed in its stand the case
puts the harddrive on its side which got me to wondering,
is there a preferred orientation for harddrives wrt to
longevity or does it not matter?
When there's no fan cooling of the drive, vertical orientation is
preferred because it keeps the drive mechanics slightly cooler and some
of the electronics as much as 20C cooler.
For at least the past 5-10 years, drive manufacturers have allowed any
orientation, but some used to require an almost perfectly vertical or
perfectly horizontal orientation, and Seagate once prohibited standing
their drives vertically with the front at the bottom, probably because
this created balance problems with the head arm assembly.
Regarding the bearings, the following, written years ago by Randy Van
De Loo, a mechanical engineer who owned a drive rebuilding business,
says orientation is irrelevant to them:
---------------------------------------------------------
"The bearing assemblys in the actuators as well as the spindles are
*ALL*
pre-loaded "ball" bearings which are of the exact same specification in
size
and pre-load top and bottom. This even includes the Maxtor FH drives
which
use "4" spindle bearings.
A ball bearing has no particular recommended orientation as far as
radial-load/thrust is concerned. It is not a heavy duty "thrust" type
bearing, but is designed to take thrust loads as high as half of it's
perpendicular or radial load. The type of bearings used in hard drives
are
generic low noise ABEC 2 - 5 sealed ball bearings. The ones we use in
rebuilding use a special lubricant which is conductive to allow the
dissipation of static in the event the static discharge tab is removed
or
somehow disabled.
Think about it this way. Ball Bearings are designed to take at least
twice the radial load as thrust load. Since this is a given, follow me
with this one, if the drive is mounted with the platters parallel to
the
plane of the earth, gravity would place the majority of the load on the
bearings in a THRUST orientation rather than RADIAL which is actually
going to cause MORE WEAR than mounting the drive on it's side. Now, if
you've followed me so far through the other conversations we've had on
the subject, you remember that I told you that the bearings are held
with
a constant "pre-load" tension (usually with bellview washers - conical
spring washers), which further changes some of this thrust load to
radial
load. This effectively makes the bearing capable of doing more work in
any position because of the distribution of the load.
As far as your friends drive is concerned:
If the mounting orientation is at fault, then the bearings must have
been
defective to begin with (it's been know to happen). Think about it
this
way. Ball Bearings are designed to take at least twice the radial load
as
thrust load. Since this is a given, follow me with this one, if the
drive
is mounted with the platters parallel to the plane of the earth,
gravity
would place the majority of the load on the bearings in a THRUST
orientation
rather than RADIAL which is actually going to cause more wear than
mounting
the drive on it's side. Now, if you've followed me so far through the
other
conversations we've had on the subject, you remember that I told you
that
the bearings are held with a constant "pre-load" tension (usually with
bellview washers - conical spring washers), which further changes some
of
this thrust load to radial load. This effectively makes the bearing
capable
of doing more work in any position because of the distribution of the
load."
