19 Nov
2003
19 Nov
'03
1:12 a.m.
From: "Pete Turnbull" <pete(a)dunnington.u-net.com>
All the rails I've ever seen have some way of
separating equipment from
rail; usually catches that can be undone to allow the unit to come
right out the front. I've seen some rails where the catches were hard
to find, hard to get at, hard to figure out, but never one without any
catch or release mechanism at all. It wouldn't make sense: if the
equipment is so heavy and/or delicate that you couldn't risk it falling
out, you don't want to make it too hard to mount in the first place.
I agree with you about it not making a lot of sense. Nonetheless, I have
seen rails that have no release buttons/clips/etc.
I was told that they were used for heavy devices and that multiple DEC
personnel with lift tables were used to install the equipment, apparently on
the assumption it was not going to be removed (without similar staff and
equipment).
I remember the couple of times I unbolted this equipment, then realized it
was too heavy for me to do anything but sink to the ground, trying to slow
the equipment's fall while keeping myself out from under it as much as
possible. Not fun.
The other thing I hate is when the rail guides pop loose during equipment
insertion or removal. The equipment sort of falls through the rack until it
hits something or reaches the maximum extension of the rail (which is
usually still attached at the back). If there is nothing to hit, it will
eventually bend up the flange on the front of the equipment.
I now make it a point never to do rack mounting without a buddy, and
something to catch the equipment if it gets away from us. (One thing that
seems to work well are the little angle-aluminum shelves like the PDP-8/a
systems use, installed temporarily just below where the equipment is to go.
I have also made similar shelves myself (since my 8/a is using the others)
from angle I bought at Home Depot. I have also used
strapping looped under
the work area, but I didn't like that as well -- the
straps can get in the
way.
Harbor freight has a special on hydraulic lift tables - $199 :-).
Vince