17 Nov
2003
17 Nov
'03
9:42 p.m.
On Nov 17, 22:01, Ian Primus wrote:
How do I get the side panel off the Digital rack? They
seem to come
off, and one is loose. I am wanting to remove it, and reattach it so
that it won't rattle. Also, the top panels are a little crooked. I
have
tried to look for how the thing is put together, but
it's hard for
me
to tell, being unfamiliar with racks. What is the
trick to removing
those panels?
There are two or three types. One has panels that pop on using springy
metal fasteners, one has sides that lift up slightly then pull off,
similar to (but not the same as) the taller racks.
What are the preferred types of screws to use for
mounting things in
racks? One of my racks has threaded holes, but the Digital one
doesn't.
Should I just go to the hardware store and get some
1/4-20 nuts and
bolts, or is there a recommended or standard size? Also, what is the
threading on racks with threaded holes? Is this a standard size bolt?
Normally, on those racks, you use clip-on Tinnerman nuts, with 10-32
screws. Some devices use a metal strip with tapped holes to take 10-32
screws. A Tinnerman nut is basically a folded piece of springy sheet
metal with a nut welded onto the back, so that it clips onto the
vertical rail and holds the nut captive and aligned with the hole in
the rail.
Also, I have a Fujitsu Eagle, which, aside from being
very heavy,
also
needs a new set of rails. It has some rails already,
but I don't have
the mating ones to put in the rack. Do most devices take standard
rails, or are there peculiarities to some drives? Will a normal set
of
rails handle a 150 pound hard drive, or do I need
something a bit
more
robust?
Pity you haven't got the original rails, they're really high quality.
Eagle rails are heavier-duty than most, but any really HD rail will be
fine, providing the holes fit.
Does it matter what order I put the hardware into the
rack? I
wouldn't
think that it would, but I'm worried about heat.
Within reason, it doesn't matter. I'd leave a gap above the Eagle. In
case you didn't already know, the rack is measured in "U" (units of
1_3/4"). 3U is 5_1/4". If you look closely you'll see the holes are
not evenly spaced, but in groups of three. The centres of the outer
holes of a 1U space are 5/8" distant from the centre of the middle hole
(and distance from centre of outer hole of one U to centre of outer
hole of the adjacent U is 1/2" ).
On a related note, how should I plug all this stuff
in? I'll have at
least three power cords, one for the computer, one for the Eagle and
one for the tape drive, then there will likely be another drive or
two.
What should I plug these into? Will a heavy duty power
strip handle
the
load, or should I split it up? What about a single
circuit? From what
I
have read, an 11/73 shouldn't draw that much
juice, the only thing I
worry about is how much current the drives need. I'd still imagine
that
a regular household 15 amp line should do it though.
15A should be plenty. I can't remember what an Eagle draws, but my
11/73 system draws less than 4A at 230V, but it has two smaler drives,
not an Eagle. The normal way to wire them up is with a power
controller in the bottom of the rack, at the back. A power controller
is basically a power strip with two sets of sockets (one always on, one
set controlled), a 2-pole (3-pole if for 3-phase) circuit breaker (not
just a switch), and a relay/contacter and associated electronics. A
3-position switch lets you turn the contactor to ON, OFF, or REMOTE,
and there are two or three 3-pin AMP Mate-N-Lock sockets for remote
connections (you can wire the BA11-x switches to turn the contactor on
and off).
--
Pete Peter Turnbull
Network Manager
University of York
18 Nov
18 Nov
1:35 a.m.
On Tuesday, November 18, 2003, at 03:42 AM, Pete Turnbull wrote:
Are these Tinnerman nuts available in places like Home Depot, or do
they need to be ordered. Something tells me that Home Depot wouldn't
carry them, since they sound specific to rack mounted hardware, but I
thought I'd ask. I'll probably just use regular nuts and bolts, those I
_can_ get at Home Depot.
I've got part of the original rails :). Bolted to the side of the drive
are sliding rails, and normally I would assume that the entire rail was
there, as the end is such that it could be screwed into the rack, but
there are only these screw holes on the front of the rails, not the
back, and I know that a 150 pound drive cannot be supported by a single
set of screws in the front.
OK, that makes sense. The Eagle is definitely going on the bottom
though :)
Ian Primus
ian_primus(a)yahoo.com
On Nov 17, 22:01, Ian Primus wrote:
I've managed to get the panel to slide up, but it doesn't want to come
off. It's like there is something keeping it from sliding up all the
way. I'll have to take a closer look at the bottom of the panel, maybe
there is something I missed.
How do I get the side panel off the Digital rack?
They seem to come
off, and one is loose. I am wanting to remove it, and reattach it so
that it won't rattle. Also, the top panels are a little crooked. I
have
tried to look for how the thing is put together,
but it's hard for
me
to tell, being unfamiliar with racks. What is the
trick to removing
those panels?
There are two or three types. One has panels that pop on using springy
metal fasteners, one has sides that lift up slightly then pull off,
similar to (but not the same as) the taller racks. What are the preferred types of screws to use for
mounting things in
racks? One of my racks has threaded holes, but the Digital one
doesn't.
Should I just go to the hardware store and get
some 1/4-20 nuts and
bolts, or is there a recommended or standard size? Also, what is the
threading on racks with threaded holes? Is this a standard size bolt?
Normally, on those racks, you use clip-on Tinnerman nuts, with 10-32
screws. Some devices use a metal strip with tapped holes to take 10-32
screws. A Tinnerman nut is basically a folded piece of springy sheet
metal with a nut welded onto the back, so that it clips onto the
vertical rail and holds the nut captive and aligned with the hole in
the rail. Also, I have a
Fujitsu Eagle, which, aside from being very heavy,
also
needs a new set of rails. It has some rails
already, but I don't have
the mating ones to put in the rack. Do most devices take standard
rails, or are there peculiarities to some drives? Will a normal set
of
rails handle a 150 pound hard drive, or do I need
something a bit
more
robust?
Pity you haven't got the original rails, they're really high quality.
Eagle rails are heavier-duty than most, but any really HD rail will be
fine, providing the holes fit. Does it matter what order I put the hardware into
the rack? I
wouldn't
think that it would, but I'm worried about
heat.
Within reason, it doesn't matter. I'd leave a gap above the Eagle. In
case you didn't already know, the rack is measured in "U" (units of
1_3/4"). 3U is 5_1/4". If you look closely you'll see the holes are
not evenly spaced, but in groups of three. The centres of the outer
holes of a 1U space are 5/8" distant from the centre of the middle hole
(and distance from centre of outer hole of one U to centre of outer
hole of the adjacent U is 1/2" ). 
2:54 a.m.
Ian Primus wrote:
On Tuesday, November 18, 2003, at 03:42 AM, Pete Turnbull wrote:
If it's like the one I had, You have to pull out, away from the rack,
on one of the bottom corners of the side panel. It gets caught on a
frame rail down there. Then a good thump upwards should pop it right
off.
--
--- Dave Woyciesjes
--- ICQ# 905818
On Nov 17, 22:01, Ian Primus wrote:
I've managed to get the panel to slide up, but it doesn't want to come
off. It's like there is something keeping it from sliding up all the
way. I'll have to take a closer look at the bottom of the panel, maybe
there is something I missed. How do I get the side panel off the Digital rack?
They seem to come
off, and one is loose. I am wanting to remove it, and reattach it so
that it won't rattle. Also, the top panels are a little crooked. I
have
tried to look for how the thing is put together,
but it's hard for
me
to tell, being unfamiliar with racks. What is the
trick to removing
those panels?
There are two or three types. One has panels that pop on using springy
metal fasteners, one has sides that lift up slightly then pull off,
similar to (but not the same as) the taller racks.
12:39 p.m.
How do I get
the side panel off the Digital rack? They seem to come
off, and one is loose. I am wanting to remove it, and reattach it so
that it won't rattle. Also, the top panels are a little crooked. I
have
tried to look for how the thing is put together,
but it's hard for
me
to tell, being unfamiliar with racks. What is the
trick to removing
those panels?
There are two or three types. One has panels that pop on using
springy
metal fasteners, one has sides that lift up slightly then pull off,
similar to (but not the same as) the taller racks.
4:18 p.m.
I worked some more tonight, and I have managed to get the PDP-11 system
box mounted, and rails in place for the tape drive. I will need some
help to hoist the tape drive up so it can go into the rack. The Fujitsu
Eagle is another story entirely. I have looked at the rails some more,
and they do appear to be safety rails, and they are missing the rear
right angle flange that would allow me to screw them into the rack.
Also, even if I did have this flange I do not know how I am to get this
drive into the rack at all. I need to somehow lift the drive up far
enough so I can screw the rails in place. The only thing that I can
think of is to stack the drive on top of something the right height
(I'm thinking of using some junk PC clones and some wooden boards), so
that I can screw in the rails, then shove the drive back into the rack.
But, there I face another snag. The Digital rack I am installing this
in is not threaded. Also, the spacing between the front and the back is
different than the other rack I have, and I noticed that some of the
rails I had didn't fit as easily as they could have. Are there really
different depths for racks? I would have imagined that a 19" rack would
be standard dimensions, but the Digital rack definitely seems to be
different than the other generic rack. Another little snag I
encountered with the Digital rack is that I _can't_ use the Tinnerman
nuts that clip onto the rails. The problem is that in the Digital rack,
the rails screw in from the _back_ of the front part, instead of the
front. If I screw them into the front, the holes in the side don't line
up with the other upright. I found a couple appropriate sized bolts
with locking nuts that I was able to use, I'm going to get some more at
the hardware store tomorrow though. So, in other words, I need a pair
of the rear right angle pieces from the Fujitsu Eagle rails (I don't
know if these are the rails it came with or not, I'll take a picture
though). Also, in the "it would be kinda nice to have" category, I
could use the front panel from a Fujitsu Eagle. It's not an important
part, it just looks nice. I can always fabricate some sort of cover
from wood though.
It's amazing how much energy and thought trivial
s**t consumes.
Amazing, isn't it? I haven't even had a chance to fire the thing up
yet, since I really need to get things organized and mounted before I
can hook everything up. It's just amazingly complicated to mount
something as heavy as a Fujitsu Eagle into a rack when you've never
done it before, and have none of the proper parts to do it.
Ian Primus
ian_primus(a)yahoo.com
5:42 p.m.
Haven't got time to comment on everything you've said.
Some tips:
Rails come in two pieces.
You can mount one piece to the drive and one to the rack.
When you have the rails in two pieces, the rack side rails
can be screwed in place with much less stuff in the way
than if the drive was there, so please do that.
Extend the rack rail and dock the drive rail to it.
Once you get one side docked, you can let it support *some*
weight, like half a drive weight, so you can move from gross
lifting to fine positioning at that later point.
Some rails are extendable.
You can loosen a screw and pull them out a little longer.
I've used nuts and bolts. Not much problem, I added locking
washers to them because these are machines that vibrate.
I've used piles of things to lift Eagles.
A table with a PC on it gave the right height and *important*
wasn't too rickety.
If the height wasn't exactly right it was alot easier lifting 1
inch than holding it up at four feet.
Eagles require friends when lifted.
John A.
6:03 p.m.
From: "John Allain" <allain(a)panix.com>
Haven't got time to comment on everything
you've said.
Some tips:
Rails come in two pieces.
You can mount one piece to the drive and one to the rack.
When you have the rails in two pieces, the rack side rails
can be screwed in place with much less stuff in the way
than if the drive was there, so please do that.
"Safety Rails" do not come apart like that. They are specifically designed
so the device *won't* go in or out through the front of the machine. It
will extend so the device can be serviced, but it won't let go so you can
take the device out and set it on a table. Likewise, you can't pick it up
from the table and engage the rail glides, then push it
on in, like you
would regular rails.
They are a pain.
To get a "safety" rail apart, you have to do a maneuver roughly equivalent
to pushing the device all the way through the *back* of the rack. Of
course, the bezel prevents that, if the rail is actually mounted to a
device.
Vince
19 Nov
19 Nov
2:34 a.m.
On Tue, Nov 18, 2003 at 10:18:30PM -0500, Ian Primus wrote:
But, there I face another snag. The Digital rack I am
installing this
in is not threaded.
That is completely ordinary. I have well over a dozen DEC racks... they
have bare holes onto which you Clip tinnerman nuts, except for the really
old racks (pre 1968) that are solid and have to be drilled for rivnuts
(you install them like pop rivets, but there's no central shaft when
you install them, just internal threads).
Also, the spacing between the front and the back is
different than the other rack I have, and I noticed that some of the
rails I had didn't fit as easily as they could have. Are there really
different depths for racks?
In effect, yes. There is no guarantee that all rails will fit all
racks. DEC rails will fit a DEC rack, though. I might have missed
something, but it's possible that your Eagle came from a generic
rack, not a DEC rack.
In practice, in the past, I've seen systems that had mixed rack styles...
DEC hardware in a DEC rack, and third-party hardware in another rack.
My PDP-8/L + BM08 came in a third-party rack with third-party rails that
just plain don't fit the CPU. Someone before me drilled extra holes
in the CPU case, but that wasn't enough - the width of the CPU itself
is about 2mm narrower than the space enclosed by the rails - I had to
find a way to shim the CPU rails with washers to get a proper fit. When
I got it, it would bind and occasionally hop the tracks. Worst
installation of DEC hardware into a rack I've ever seen. If I had a set
of rails for the -8/L, I'd have moved it all to an H960 long ago, but
all of my -8/Ls came as table-top or rail-less.
Your fit issues are nothing modern.
Personally, I was surprised the first time I ran into "modern" racks
for PeeCee servers. One of the things I like about DEC racks is that
you don't have to worry about stripping out threads in the rack uprights.
I've only ever had to throw away a few Tinnerman nuts, but that's a lot
better than ruining a thread on a rack.
Just this week, we ran into a rack incompatibility at work: we received
rails for some modernish Compaq server that wants to mount into a rack
with square holes that normally accept another style of clip-on nut.
The rack, unfortunately, is of the pre-threaded variety. We ended up
bending back the locking tabs meant to rest in the square holes, and
boring out one of the threaded holes to accept a #12 bolt. For next
year, though, I think we'll bring down a real HP/Compaq rack and
replacement rails.
--
Ethan Dicks, A-130-S Current South Pole Weather at 19-Nov-2003 13:20 Z
South Pole Station
PSC 468 Box 400 Temp -39.2 F (-39.6 C) Windchill -60.1 F (-51.2 C)
APO AP 96598 Wind 6.6 kts Grid 031 Barometer 677.5 mb (10719. ft)
Ethan.Dicks(a)amanda.spole.gov http://penguincentral.com/penguincentral.html
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7 comments
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participants (6)
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allain＠panix.com -
dickset＠amanda.spole.gov -
dwoyciesjes＠comcast.net -
ian_primus＠yahoo.com -
pete＠dunnington.u-net.com -
vrs＠msn.com