Racks and frack racks

[Daniel Gendreau]

Note: The urls I have listed below are from some vendor site. I include them
because they have illustrations and information about racks, and not as a
plug.

When I looks this stuff up, I usually just go to:
http://www.lashen.com/vendors/MidAtlantic/default.asp

Most standard racks are 19" wide and a multiple of 1.75"(refered to as U)
high.
ie. a 3U panel is 5.25in high by 19" wide.

The rails that run down the sides of the rack have 3 holes per U, evenly
spaced 7/12" apart I believe, but I do recall seeing rails where the holes
were not exactly evenly spaced. Rack screws are 10/32 thread (not metric).
Many people like to use plastic washers to reduce ground loops and paint
gouging.

The hole centers in your rack panels will be 7/24" or 21/24" in from the
edge (where X is 0 thru whatever you want). For frac rack panels, 7/24" in
from both edges in the 4 corners would be appropriate. The panel mounting
holes are probably 1/4" Diameter, but I am not sure here.

To make a frac rack, people often create a set of 19" rails that run across
the rack with the same hole spacing as the vertical rails. Make sure you
give yourself 1/2in to 1in room on the ends for mounting. check the second
picture on this page:
http://www.lashen.com/vendors/MidAtlantic/pages/ucp.asp

By using the same spacing as the vertical rails, you can then make frac rack
panels that are multiples of UxU in size. So if you space your horizontal
rails 3U appart, you can use 3Ux1U, 3Ux2U, 3Ux3U etc. frac panels in that
row.

Hope this helps,
-Dan Gendreau