[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: [OT] Re: Computer case



* Ralf Mardorf <ralf.mardorf@alice-dsl.net> [120602 17:33]:
> ... Most of my music gear is 19" too. I placed the gear
> on shelfs, but I tend to switch to a 19" cabinet, to get rid of the wide
> and lengthy shelfs. A tower could be > 26" high, if I would get rid of
> the shelfs. The only issue, a 19" or a new tower computer case + a 19" cabinet is
> above my financial scope.

You can build your own wooden 19-inch rack in three or four hours.
Use hardwood if it is available at low cost; otherwise use plywood or
pine.

Not including the front and back (if any), you need six pieces of wood
(three pairs of pieces).  Assuming 3/4-inch actual thickness (1-inch
nominal):

    => top and bottom: about 19-1/8 inch wide, and whatever depth you
    need for the rack-mount gear

    => inner side panels (into which the rack screws are inserted): an
    inch or two less than the depth of the top and bottom, so that
    knobs and switches are recessed and thus protected from damage)
    and as tall as you need for your collection of rack-mount gear
    (1-3/4 inch per single-height panel); you can allow for future
    expansion by installing several blank panels

    => outer side panels: the same depth as the top and bottom, and a
    at least 1-1/2 inches taller than the inner side panels; make them
    taller if you wish to keep items such as pencils and pens from
    rolling off the top of the rack

Note that the top and bottom panels rest against the inner side
panels.  The primary function of the outer side panels is to provide
rigidity to the structure.

Now here is the secret for an inexpensive homebuilt rack: thread the
rack screws directly into the inner side panels.  If at all possible,
find someone with a drill press (so that the axis of the holes are
square with the panel), and make yourself a jig to ensure that hole
spacing is correct.  

Take a scrap of wood and experiment: choose a drill bit which
allows you to install a standard rack screw (10-32 -- that is, No. 10
screws, 32 threads per inch) as if it were self-tapping.  A bit
which is about a millimeter smaller than the outsider diameter of the
10-32 screw should be about right.

The first time you install a screw in a hole, the fit should be rather
tight, so that the threads which are being formed in the wood do not
strip.  (The screw is going to get rather warm from the friction.) But
once you have installed a screw fully into a hole and then remove it,
it should screw back in without much difficulty.

If you make a large rack and thus use soft wood for the inner side
panels, you can make a better rack if you reduce the depth of the
inner side panels by, say, two inches, and replace the missing depth
with a pair of 1-inch by 2-inch hardwood strips.  Hardwood provides a
secure grip for the screws, and it is easier to drill holes accurately
into strips than into large side panels.

If you do not care about appearance, you can mount rack gear using
wood screws, sheetrock (or drywall) screws, outdoor deck screws, or
even sheet metal screws.  But it does not take long to follow the
procedure above so that you can use standard 10-32 rack screws, in
which case the appearance of the rack is going to be really nice,
particularly if you sand the box and then varnish or paint the rack.
But even bare wood is not unattractive.

Assemble all six pieces of wood (or eight pieces, if you use drilled
hardwood strips) using 1-1/4 inch wood screws or deck screws and
carpenter's glue.  In the end, it is easier if you:

    (1) drill and countersink all the holes and fit everything together
    loosely with wood screws but without glue; a combination
    drill-and-countersink bit is useful

    (2) mark the pieces (so you can get them back together in the same
    arrangement, with all holes matching precisely)

    (3) take apart the pieces

    (4) apply glue

    (5) reassemble the rack tightly with wood screws

    (6) allow the glue to dry overnight before you load gear into the
    rack

With this technique, you are going to have an almost-indestructible
rack which is acoustically dead.  Needless to say, the rack is going
to be heavy.

And with the dual-side-panel design, the inner side panels (and not
just wood screws) support the top.  This allows you to pile gear
weighing a hundred pounds or more on top of the rack -- in addition to
the gear which is mounted in the rack.

RLH


Reply to: