Christopher Jeris (01:49 PM 07/21/1999) wrote:
>Paul> I agree. Usually, the bottom 12U holds a 400lb power supply! Not
>Paul> MOTM-happy.
>
>Mark> The tall relay racks are usually bolted to the floor...
>
>Hm. I can't bolt things to the floor in my apartment (never mind that the
>building is so far below code, bolting anything to a floor beam would
>probably crack it). But the picture of a relay rack in the Newark catalog
>shows base flanges extending a little ways front and back from the bottom
>of the rails, I guess to put bolts into. You think I could maybe hold it
>down with a few 15kg lead bricks? If you normally bolt those flanges
>down, they must be strong enough that the thing doesn't bend and fall over
>to front or back when you put equipment in it, right? So maybe (since
>MOTMs are really pretty light) it would be enough just to weight the base
>down instead.
Yes, you can weight them down, but at 15kg a pop, you're gonna need a few
bricks.
There's some physics involved here that I don't know the math for, but
basically, it will take a lot less weight than you may think at the top of
the rack to topple the whole thing. You have to get a good amount of weight
at the bottom to stop it from happening.
The flanges at the bottom are quite strong... Double welds, heavy gauge
steel and all that. Just load 'em up with weight and make sure that the
weight doesn't have a way to shift off of the legs.
To help this, try bolting the bottom of the rack to a piece of 3/4"
plywood, and then stacking the weight onto the wood. That'll give you more
surface area to put weight on.
Something else...
Most racks I've seen do NOT ship broken down. If you're in an apartment,
you might wanna think about just how you're gonna get the rack up any
stairs and in place. Also, shipping costs can be quite high.
Mark