[Beowulf] flange clearance on sliding rails

[David Mathog]

We have two racks in the machine room.  They are both generic
(ie, not from a major manufacturer like Dell, Sun, or IBM.)
Neither one of them will hold a set of sliding rails properly.

When I set mine up I pushed the forward vertical rails
all the way to the front of the case.  That didn't cause any problems
with the flanges on the nodes which are permanently mounted.  However
the flanges on the ends of rails hit a structural member on
the front/outside of the case.  So the rails are displaced
inwards a couple of millimeters  andthe resulting space is
about 4 mm too narrow to hold a case.

The other rack, from another group, has the same problem on one
side.  For that one (square holes with the little clamp in nuts)
there's absolutely nothing to adjust.  What's most infuriating about
this case is that there's almost 2 inches of free space on the other
side, all they had to do was to make the narrower rail a tiny bit
wider, and the wider one a tiny bit narrower.

In both cases the mounting flanges are only about 2 mm too wide.
I've seen this now with rails from two different sources.

Is this a common problem?

Does somebody make sliding rails which have flanges that are
just a bit narrower?

At the moment we only need to mount one set of rails so I
guess we'll have to take it over to the metal shop and have
them cut or grind 2 mm off of the flange on one side.

Thanks,

David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech